2015 Proceedings 57th Annual Horticulture Growers’ Short Course
2015 Proceedings
January 29-31, 2015
Editors: Todd Kabaluk Lisa Frey Michael Dossett
Sponsored by:
Lower Mainland Horticultural Improvement Association LHMIA 2014/2015 Board of Directors
Members: Ex Officio:
Andrew Arkestyn-Vogler Donna Anaka Mike Boot Jennifer Curtis Trevor Harris Michael Dossett Jeff Husband Sheila Fitzpatrick Brian Johnston Elsie Friesen Alf Krause Shawn Halter Sid Kwantes Gary Jones Ed McKim Todd Kabaluk Grant McMillan Dave Trotter Heather Meberg Bob Vernon David Mutz Dave Woodske Lydia Ryall Kerry Seale Harvie Snow Ria van Eekelen Bruce Wisbey
Executive Director: Sandy Dunn
President: James Bergen Vice-President: Jordan Krause Secretary: Susan Smith Treasurer: Mark Sweeney
Foreword
These Proceedings summarize three days of meetings and educational seminars at the 57th Lower Mainland Horticultural Improvement Association Short Course held in conjunction with the 17th Annual Pacific Agriculture Show from January 29 -31, 2015 in Abbotsford, BC. There were 819 registered for the Short Course and 157 for the Ag-Energy session, and 82 presenters, along with over 280 exhibitors and over 7,400 general attendees at the Pacific Agriculture Show. The Short Course provides an opportunity for participants to learn about the recent progress in research and development, sustainability and innovation, marketing, agricultural programs and policies, and the ever-changing face of the horticulture industry in BC. This event is organized by the LMHIA Board of Directors, which includes growers, agribusinesses, government and university personnel – all of whom deserve credit for its delivery. Short Course evaluations this year indicated a very high rating for both the choice of speakers and the topics presented. The introduction of Twitter (#pacagshow) in 2013 was so successful that we expanded our social media presence, with the following sites planned for use into the future:
Twitter: www.twitter.com/pacagshow Facebook: www.facebook.com/pacificagricultureshow Instagram: www.instagram.com/pacagshow
This volume contains summaries written by the speakers themselves. The LMHIA Board, and all others involved in the Short Course acknowledge and appreciate the widespread participation of the speakers in drafting summaries of their presentations to be included in these Proceedings. The Proceedings stand as a resource of information for the horticulture industry as a whole, and a record of the state of development of agriculture in BC. Revenue generated by the Short Course enables the LMHIA to award research projects in support of agriculture in BC.
We look forward to seeing you at next year’s Short Course from January 28 - 30, 2016.
The Editing Committee - Todd Kabaluk, Lisa Frey, Michael Dossett
The summaries presented in this volume were submitted by the presenters themselves. The BC Ministry of Agriculture, the LMHIA, and the editors of this publication do not assume liability for crop loss, animal loss, health safety or environmental hazard caused by the use of information described in this publication. Table of Contents Strawberries/Raspberries
New Techniques for Getting Raspberries and Strawberries Off to a Better Start ...... 8 Eric Gerbrandt
Current and Future Options for Soil Fumigation: A Washington State Perspective ...... 11 Thomas Walters
Strawberry and Raspberry Cultivar Development at Washington State University ...... 14 Patrick P. Moore
Raspberry and Strawberry Variety Developments ...... 17 Eric Gerbrandt
Evaluation of New Products for Weed Control in Raspberry and Strawberry ...... 20 Tim Miller and Carl Libbey
Day-Neutral Strawberries: Recognizing and Managing Insect Pests ...... 25 Emily Carmichael
2015 Processed Red Raspberry Market Outlook ...... 31 Jen Dhaliwal
Greenhouse Vegetable
To Fog or Not to Fog: That is the Question ...... 35 Mark Stanley
Strategies for Biocontrol of Aphids in Greenhouse Vegetable Crops ...... 38 Gerben Messelink
From the Depths of the Earth to Your Customer’s Kitchen ...... 40 Alison Thompson
Agro-Forestry/Alternative Crops Cold Climate Food Forest Agroforestry ...... 42 Michelle Heinz
Cariboo Silvopasture: Zirnhelt Ranch...... 45 David Zirnhelt Horticulture Growers' Short Course 4 Potatoes
2014 BC Potato Variety Trial: With a View from the Kitchen ...... 48 Heather Meberg
Floriculture
Pot Azaleas, Flanders' Pride: How Breeders, Growers and Researchers Join Efforts to Create a Success Story...... 51 Stefaan Werbrouck
How to Establish Natural Enemies in Ornamental Crops ...... 55 Gerben Messelink
Western Flower Thrips: Is The Game Over? ...... 57 Raymond Cloyd
What Is the Real Story Behind Declining Bee Health ...... 59 Elizabeth Elle
New Tools and Advances to Battle the Mildews...... 63 Mary Hausbeck Field Vegetables
Yellow Nutsedge: A Beast of a Weed ...... 67 Tim Miller
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Nursery
Characterization of Rose Black Spot in Canada ...... 80 Anissa Poleatewich, Irina Perez Valdes, and Rumen Conev
What is All the “Buzz”: Systemic Insecticides and Pollinators ...... 82 Raymond Cloyd
Drip Irrigation of Nursery Crops ...... 85 Inge Bisconer
Horticulture Growers' Short Course 5 Farm-Direct Marketing Opening Remarks for Direct Marketing Session ...... 98 Murray Siemens
Pricing, Distribution & Profitability ...... 100 Andrea Gray-Grant
Agri-Energy and Waste Management Forum See link: https:/www.bcac.bc.ca/ardcorp/program/renewable-agri-energy
All Berries The Blueberry Experience with Spotted Wing Drosophila in 2014 ...... 102 Tracy Hueppelsheuser
Yellow Nutsedge: An Increasing Weed Threat to Berry Crops ...... 105 Victoria Brookes
Blueberries Evaluating New Pesticides for Insect Control in Blueberries and Raspberries ...... 108 Carolyn Teasdale
Tissue Testing in Blueberry: What Have We Learned? ...... 112 Bernadine Strik and Amanda Vance
What Causes Green Fruit Drop and Can We Prevent It?...... 115 Eric Gerbrandt
From Planting to Maturity: Which Cultivars Rise to the Top? ...... 119 Bernadine Strik and Amanda Vance
Hazelnuts New Hazelnut Cultivars and a Trial to Evaluate Them in BC ...... 121 Thom O'Dell and Haley Argen
A Preliminary Report on Hazelnut Enterprise Budget in British Columbia ...... 126 Wallapak Polasub
BC Hazelnut Industry Development Plan ...... 128 Darrell Toma
Horticulture Growers' Short Course 6 Organics
Keeping the Door Shut on Invasive Vegetable Pests...... 131 Tracy Hueppelsheuser
Environmental Farm Planning: A Tool to Manage Nutrients ...... 134 David Poon
Cover Crops to Achieve Multiple Farm Goals ...... 138 James LaChance and Mitch Hunter
Evaluating Techniques for Better Blueberry Pollination ...... 144 Elizabeth Elle and Kyle Bobiwash
Weevils in Blueberries: Identification and Management...... 145 Tracy Hueppelsheuser
What is Needed to Get Your Products Listed in a Major Supermarket? ...... 148 Ken Clark
Taking a Good Look at Irrigation Water is a Good Idea ...... 149 Justin Falardeau, Siyun Wang, and Pascal Delaquis
Nitrate Accumulation in Vegetables: Something to Avoid ...... 152 Michael Bomford
Keeping Food Safe to Eat: From Producer to the Consumer ...... 158 Alison Speirs
Post-Harvest Handling of the Vegetable MixTips for Success ...... 160 Bruce Wisbey
Post-Harvest Vegetable Handling Techniques and Tips ...... 162 Harvie Snow
LMHIA Research Grants Awarded
LMHIA Research Grants Awarded March 2015 ...... 165
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New Techniques for Getting Raspberries and Strawberries Off to a Better Start
Eric Gerbrandt University of the Fraser Valley, Abbotsford, BC [email protected]
Raspberry Planting Trials
Last year’s proceedings included a description of a first round of trials (2012/2013) that compared the establishment of raspberry tissue culture plugs planted in the fall and spring with bare-root planting in spring. These trials were conducted in open ground, which is the standard in the Pacific Northwest. In 2013/2014, a second round of trials evaluated how these results would transfer to the plasticulture system (i.e., when plants are established with a plastic row mulch). To this end, tissue culture plugs of ‘Chemainus’ and ‘Saanich’ were planted on October 13 and April 29 on a single farm location in Abbotsford, BC. For comparison, bare-root plants of ‘Chemainus’ were planted at the same time in the spring, ‘Saanich’ bare-root plants not being available at the time of these trials. First year establishment of these planting treatments was monitored over the season (Figure 1) and evaluated by measurement of the number of canes and their length at the end of the season.
A completely randomized design with four replications of each of these five combinations of planting times and material was duplicated in two rows. It should be noted that the field had not been fumigated and, the row having been formed in the summer of 2012, there were very high nematode levels. This presented the opportunity to take a first look at a fungicide product that was recently determined to have potential as a nematicide (Luna® Privilege). Therefore, as an observational trial, this fungicide was applied to one of the two rows, which was compared with the row that was not treated. Four pseudo- replicated soil counts of root lesion nematodes (Pratylenchus penetrans) were conducted in each row before application (May 5) and at the end of the season (October 23) after application (May 5 and June 5). The non-replicated results of this experiment demonstrated that Luna® Privilege likely has an effect on nematode numbers, as the increase in nematodes over the season was twice as great in the untreated row as the treated row. Replicated research is required before any statistically valid conclusions can be drawn.
Figure 1. A ‘Saanich’ tissue culture plug growing through plastic mulch after planting on October 1, 2013 (photo taken June 5, 2014)
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The findings of these trials are summarized as follows: • Under plastic mulch, tissue culture plug plantings in fall and spring compare similarly with bare-root plantings in the spring as they do when planted in open ground. This means that this flexible system for raspberry planting warrants further investigation as a means of early establishment in the Pacific Northwest. • It is vital that tissue culture plugs have a considerable root mass to be able to compete with bare-root plants, but this is a question of what can be economically produced. Specifically, a 100 to 150 mL plug size is likely sufficient to obtain adequate growth, but the bigger the better. • Tissue culture plugs demonstrate a different growth habit from bare-root plants. In general, they tend to produce a more consistent crop of long canes whereas the bare-root plants make a greater number of canes of variable length. As a short-term benefit, the baby crop yield in the following season may be superior with a more consistent crop of canes in the establishment year. • The primary advantage of the tissue culture plugs is that they are produced in a relatively “clean” environment, making them more likely to be pest and disease free in comparison with a bare-root plant. As a long-term benefit, the early establishment of a planting with “cleaner” planting stock should help delay the eventual decline of a planting due to the raspberry yield decline complex. • Additional opportunities presented by the use of tissue culture plugs and plastic mulch are: o Additional bed fumigation options that will deal with recent changes in fumigation regulations. o The flexibility to work a field in the fall and then plant either earlier in the spring. Future research is underway to integrate these findings into a more comprehensive set of field trials that will compare bed fumigation, plasticulture, bare-root and tissue culture plugs, a range of raspberry genotypes and various organic amendments. As well, these findings point toward more questions of how to optimally use bed fumigation to control soil-borne diseases before and after planting.
Strawberry Planting Trials
As described above for raspberry, a first round (2012/2013) of planting trials for day-neutral strawberry were described in last year’s proceedings. A second round (2013/2014) of trials picked up where these trials left off, comparing summer/fall plantings of runner-propagated ‘Albion’ plantlets (Aug. 12, Sept. 2 and Sept. 23) and summer planting of bare-root (i.e., frigo) plants (Aug. 12) with the standard bare-root planting in the spring (Mar. 26). These trials were conducted on a single farm location in Langley, BC using ten plant plots with four replications in a randomized complete block design. The first of two years of fruit harvest is now complete, resulting in the following preliminary findings:
• With significant early-season yields (Figure 2), a range of late summer plantings of runner- propagated ‘Albion’ plantlets can be used as viable alternatives to the standard spring planting of bare-root plants. • Conversely, with more modest yields and low average fruit weight, early fall planting does not have an advantage over the standard. • With loss of vigour during cooler storage and poor summer/fall establishment, frigo bare-root plugs are not a viable alternative in comparison with runner-propagated plantlets.
These findings, being preliminary in nature, will be subjected to revision upon collection of a second year of field data in 2015 and a subsequent comparison of return on investment for each planting date and material combination.
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Acknowledgements
Participating growers; Tom Baumann and Andrew Gerbrandt (Expert Agriculture Team Ltd.); Mark Sweeney and Maria Jeffries (BC Ministry of Agriculture); Tom Forge (Agriculture and Agri-Food Canada); and Michael Dossett (BC Blueberry Council).
Funding
Raspberry Industry Development Council; British Columbia Strawberry Growers’ Association; and Lower Mainland Horticultural Improvement Association.
Figure 2 Fruit yield (lbs per 10 plant plot) of different ‘Albion’ planting time and material combinations over 18 weekly harvests in 2014 in Langley, BC.
Horticulture Growers' Short Course 10 Strawberries/Raspberries
Current and Future Options for Soil Fumigation: A Washington State Perspective
Thomas Walters Walters Ag Research, Anacortes, WA [email protected]
As in BC, Washington raspberry growers rely on soil fumigation to get their plants off to a good start, free from soilborne disease and plant parasitic nematodes. Standard soil fumigation practice for raspberries in Washington State has been to kill the old crop with a Roundup/Crossbow combin- ation, remove posts and wire, chop and grind up the old crop, and rip and cultivate the soil. Fumigation usually takes place in September and early October, when soil temperature is above 50 F and soil moisture is in an appropriate range. Most fumigation is applied by a custom applicator, using a combination of Telone (1,3-D) and chloropicrin. No tarps are applied due to cost, but the surface is packed with a roller packer. Oftentimes, a small grain cover crop is seeded just before fumigation. This system has given growers decent protection from nematodes and diseases for a couple of years, but the cost is high ($1100-$1800/A), and the USEPA’s buffer requirements make it very difficult to fumigate fields with structures nearby.
Washington growers are experimenting with some alternatives. One grower is trying substituting a fallow year with a mustard cover crop for soil fumigation. Dr. Inga Zasada (USDA-ARS Corvallis, OR) and I helped him select a field with moderate (not high) root lesion nematode pressure, and very little disease. He removed the old crop in September 2013 and seeded a wheat cover crop. Dr. Zasada found moderate numbers of root lesion nematodes on the cover crop that winter. In April 2014, he seeded a white mustard (Sinapis alba) cover crop, and chopped and incorporated it in July. Dr. Zasada’s lab found very low levels of root lesion nematodes on weed roots in this field following the incorporation (Table 1). He planted a wheat cover crop again in September 2014, and the nematode numbers on that cover crop compared favorably with fumigated fields sampled then (Table 3). So, the early indications for this field are good, but we will continue to follow it.
Table 1. Root Lesion Nematode numbers in a field with a mustard cover crop, and in an adjacent raspberry field.
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Trident Ag Products, the custom fumigator in Washington, recently built a bed fumigation rig for raspberry. This makes high, wide beds, and we are looking forward to trialing it in 2015.
Another grower is trialing a new soil fumigant called Dominus. The active ingredient in Dominus is allyl isothiocyanate, which is chemically related to the breakdown product of Vapam and other metam products. Buffers for Dominus are extremely low, only 25 feet. The product has a strong horseradish smell. When we applied it, the odor was not a problem as long as we kept the shanks underground. The odor dissipated quickly. Dominus will be expensive though. This grower set up a trial comparing Dominus (40 gallons/A), Vapam (75 gallons/A) and Telone C-35 (35 gal/A) in a field with heavy root lesion nematode pressure. The Telone C-35 was applied by Trident with a deep shank rig; Dominus and Vapam were applied by the grower with a specialized rig having injections points 5 and 10 inches below the surface, with shanks 4 inches apart. A cover crop was seeded over all the treatments. We sampled the cover crop, and Dr. Zasada found nematodes in all of the plots, but the shallow-applied Dominus and Vapam had lower numbers of nematodes than the deep-applied C-35 (Table 2).
Table 2. Root Lesion nematodes in roots before and after fumigation.
We are also learning about the limitations of our current fumigation practices. We sampled the winter cover crop on 6 other recently fumigated fields, as well as the mustard crop and the fumigation comparison fields described above. Once Dr. Zasada’s lab processed the samples (Table 3), we were surprised to find that in nearly every case, root lesion nematodes were present on the cover crop roots of recently fumigated fields. The cover crops may be acting as a bridge, allowing nematodes that survive fumigation to infest the following raspberry crop. Obviously, cover crops prevent soil erosion and contribute other benefits to the system, but our fumigation practices don’t seem to protect them adequately. We’ll be looking at this more in the future.
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Table 3. Root Lesion Nematodes in the roots of cover crops over freshly fumigated fields.
We plan to continue to evaluate these fields in 2015, and to establish new trials to find better ways to address our soil fumigation needs.
Horticulture Growers' Short Course 13 Strawberries/Raspberries
Strawberry and Raspberry Cultivar Development at Washington State University
Patrick P. Moore WSU Puyallup Research and Extension Center, Puyallup, WA [email protected]
Strawberries
Objective: To develop short-day strawberry cultivars that are adapted to the PNW for processing and fresh use and have higher picking efficiency than current industry standards. Breeding day-neutral strawberry cultivars for fresh market use has been added to the WSU breeding program and crosses have been made and seedlings and selections are being evaluated.
Puget Reliance (1994) This cultivar was the result of a cross of an aphid resistant WSU selection with a BC selection. Although ‘Puget Reliance’ did not inherit aphid resistance, it is vigorous, large fruited (by 1994 standards) and highly virus tolerant. Although some newer cultivars have larger size, ‘Puget Reliance’ has found a place in the industry, primarily as a fresh market cultivar.
Puget Crimson (2010) This cultivar has many of the same characteristics as ‘Puget Summer’ (one of its parents). They both ripen at the same time, have excellent flavor and are susceptible to powdery mildew. However, unlike ‘Puget Summer’, ‘Puget Crimson’ has large fruit in both first and second fruiting season. Size of ‘Puget Crimson’ fruit is similar to ‘Tillamook’. Early fruit can average 35 g or more. ‘Puget Crimson’ has been patented (USPP 22,781) and Plant Breeders’ Rights for Canada was granted January 3, 2014, certificate No 4689.
Raspberries
Objective: To develop processing red raspberry cultivars that are adapted to the PNW and that are machine harvestable. Additional traits to incorporate into new cultivars are RBDV resistance and root rot tolerance.
Cascade Delight This cultivar was released by Washington State University in 2003 as a late season, fresh market cultivar with large, firm fruit and good field tolerance to root rot. The fruiting season and productivity is very similar to ‘Tulameen’ when both are grown on a good site. Fruit size and firmness are greater than ‘Tulameen’. However, ‘Cascade Delight’ will perform well on sites where ‘Tulameen’ is killed from root rot. ‘Cascade Delight’ is very vigorous with long fruiting laterals and fruiting laterals may break at the attachment to the cane. ‘Cascade Delight’ is recommended only for fresh use.
Cascade Gold (2010) WSU 991 produces large, firm fruit with very good yields and excellent flavor. Fruit of ‘Cascade Gold’ releases easily, even at a relatively light fruit color. Evaluation in root rot plots indicated ‘Cascade Gold’ is susceptible to root rot. . Plants of ‘Cascade Gold’ were tested for RBDV resistance by graft inoculation and tested resistant to the common strain of RBDV.
Horticulture Growers' Short Course 14 Strawberries/Raspberries
Cascade Harvest WSU 1507 was released as ‘Cascade Harvest’ winter 2013-14. ‘Cascade Harvest’ has been evaluated in several Machine Harvesting Trials and the fruit releases very easily. The fruit flavor has been very good, with sweetness equal or greater than ‘Meeker’ and pH similar to ‘Meeker’. In root rot trials at Puyallup, ‘Cascade Harvest’ has been highly tolerant to root rot. Plants of ‘Cascade Harvest’ were tested for RBDV resistance by graft inoculation and tested resistant to the common strain of RBDV. In hand harvested plots at WSU Puyallup, ‘Cascade Harvest’ has had yield similar or greater than ‘Meeker’. In a small plot with a commercial grower, ‘Cascade Harvest’ had much greater yield than ‘Meeker’. ‘Cascade Harvest’ combines machine harvestability, root rot tolerance, RBDV resistance with high yield potential and very good flavor. With the easy fruit release, ‘Cascade Harvest’ may be suitable to either processing or fresh market uses. US plant patent and Plant Breeders’ Rights for Canada have been applied for.
Promising Selections
Machine harvesting trials for the WSU program were planted for the first time in 2002 and new plantings have been established annually. There are a number of selections that have machine harvested very well in these plantings and may be released in the near future. Three WSU selections and ‘Rudi’ were planted in Grower Trials with cooperating growers in Oregon and Washington in 2012. A WSU selection (WSU 1507) was released as ‘Cascade Harvest’. A “baby” crop of these plantings was harvested in a few locations in 2013 and the first full evaluation was in 2014. Some growers were interested in WSU 1912 because of the fruit quality. It is also highly tolerant to root rot and will produce a significant fall fruit crop. There are concerns that the yield my not be high enough. A second Grower Trial of four WSU selections was planted in 2014. These four selections have only been tested in grower trials for one or two fruiting seasons. All four selections pick very cleanly and all have firm to very firm fruit. All four have good flavor, with all of them having acidity similar to ‘Meeker’ or higher and three with soluble solids similar to ‘Meeker’ or higher. Two selections combine high anthocyanins, high sugar and high acids which should be a desirable combination for a new processing cultivar. These selections were planted in 2014 and will be harvested in 2016 and 2017. Additional testing for disease resistance and performance in hand harvested plots will also be conducted at Puyallup. Selections that perform well could be released after the 2017 fruiting season.
2013-2014 Plant Sales
Each year, plant sales information is voluntarily provided by the plant propagators that sell plants into Oregon, Washington and British Columbia. Thanks to Lassen Canyon Nursery, Norcal Nursery, Northwest Plants, North American Plants, Nourse Farm and Spooner Farms for providing the plant sales information. Data has been collected for strawberries since 1985, raspberries since 2001, blackberries since 2002 and black raspberries since 2003 except in 2006 and 2007.
Strawberry
Total strawberry plant sales in the PNW decreased by 2.8% compared with the previous year. The same seven cultivars were the most sold plants in 2014, in the same order as in 2013 with the exception of ‘Tillamook’ having higher sales than ‘Albion’ in 2014. In 2014, ‘Tillamook’ was the most planted (17.8%), followed by ‘Albion’ (16.2%), ‘Totem’ (12.9%) and ‘Hood’ (11.0%). In BC, ‘Albion’ was the most widely planted with 37% of the total, ‘Puget Reliance’ was second with 12.4% and ‘Rainier’ third with 11.1%.
Horticulture Growers' Short Course 15 Strawberries/Raspberries
Raspberry
After decreasing total raspberry plant sales since 2009, sales were up 1.9% in 2014. However, plant sales continued to decrease in Oregon, a 35% decrease from 2013 to 2014. Plant sales in Washington increased by 1.5% and in BC by 32.7%. However, plant sales in Oregon and BC in 2014 are 75% less than sales in 2009 and Washington is 40% less. ‘Meeker’ continues to be the most widely sold cultivar with 40.8% and ‘Wakefield’ continued to be second with 32.8% of the total, ‘Chemainus’ was third, with 7.5%. In BC, ‘Chemainus’ was the most widely sold with 37% and ‘Meeker’ second with 30.5%, none of the other cultivars sold more than 10%.
Blackberry
Total blackberry plant sales increased by 50%, led by a 73% increase by Oregon and a 19% increase in Washington. In BC, the total blackberry sales decreased by 89%. ‘Black Diamond’ remained the most widely planted with 34% and the newly released ‘Columbia Star’ was second with 31%. ‘Marion’ has consistently been among the more widely planted cultivars, but was only ninth with 1.9% of the total. In BC, ‘Loch Ness’ was the most widely planted with 36.2% and ‘Natchez’ second with 27.1%.
Black Raspberry
Total black raspberry plant sales decreased by 46% with a 39% decrease Oregon and a decrease of over 90% in Washington. No black raspberries were sold in BC. ‘Munger’ was the most widely planted with 96% of the total.
Horticulture Growers' Short Course 16 Strawberries/Raspberries
Raspberry and Strawberry Variety Developments
Eric Gerbrandt University of the Fraser Valley, Abbotsford, BC [email protected]
The berry breeding program in BC is vital to moving the local industry forward in an increasingly competitive marketplace. Challenges such increasing land and labour costs, loss of chemical tools and greater pest and disease problems make genetic advancement through breeding of superior varieties an important priority. Part of the process of breeding better berries is the evaluation of these varieties in grower/variety trials.
Perspectives on Grower Trials
• Translating the breeding program to the industry: Grower trials are the process of translating the breeding program to the industry. After years of development under experimental conditions, potential varieties (called ‘selections’) must pass this final test. If a selection does not perform well under standard industry production practices, on a variety of farm locations and over a number of years, it should not receive a variety name and be released for wide-spread planting. The opinions of the expert growers, who give of their land and time to evaluate potential varieties, dictate whether it will be named and released for use in the industry.
• Transferring technology from around the world: In addition to the evaluation of selections from the local breeding program, grower trials are used to evaluate berry genetics from around the world. If genetics are thought of as a type of biological technology, this is the process of technology transfer from other parts of the globe. All plant varieties have limits to their range of adaptation and so evaluation under the specific climatic, production and regulatory environment found in BC’s Lower Mainland is a necessary first step before new varieties can be recommended. Sometimes this involves an early look at selections from other breeding programs that have not yet been released as varieties and other times it means evaluation of varieties that have already been released.
• Determining what works: The question that is asked of each selection and variety in grower trials is whether it “works” or not, which is always relative in comparison to industry standard varieties and to the specific market for which the grower is producing. Though this may seem like a simple question, it encompasses many other questions, including:
♦ Does it establish well? ♦ Does it have high yields? ♦ Does it have good fruit quality? ♦ Is it easy to harvest? ♦ Is the harvest window appropriate for the market to which it is best suited? ♦ Is it resistant/tolerant to important pests and diseases?
• Discovering management requirements: At the same time as grower trials tell the industry whether a selection or variety will “work”, they also provide indications as to how management should differ from that of industry standard varieties with which the industry has production experience. These are questions that may take further years of experimental research and industry experience to fully figure out, but grower feedback tends to highlight the most important
Horticulture Growers' Short Course 17 Strawberries/Raspberries
needs of a variety. These observations can be used to either get a general sense for what special treatment the variety requires or what sort of experimental research should follow. Determining differential management requirements is the result of a diversity of questions, including:
♦ Does it need harder or lighter pruning? ♦ Does it require more or less fertilizer? ♦ Does it do better in one soil type or another? ♦ Does it benefit from more or less pest and disease control applications? ♦ How well does it do with winter water conditions?
Objectives and Methodologies
• Providing support to the breeding program: Through translating the breeding program to the industry, grower trials are used to provide another level of information gathering for the breeding program. The objective and subjective observations generated through grower trials provides the breeder with a broader sense of how the products of their labour are faring in the hands of the people for whom they were developed. This can be used to modify future breeding strategies, enhance the objectives of the breeding program and measure progress of past efforts.
• Linking growers with the most up-to-date information: When growers plant varieties from other regions they have the chance to gain a competitive advantage in the marketplace, but they are also risking an expensive total or partial failure. For the industry as a whole, a coordinated effort to evaluate new varieties as soon as they’re publicly available is the most prudent approach as it allows for mistakes to be made on a small scale before individual growers invest time and effort into an unproven product. The variability in a variety’s performance from one region to the next (i.e., its range of adaptation) is a complex riddle, with an answer that is hard to predict. Grower trials help to remove some of the guess work.
• Improving recommendations: With feedback from growers and broader evaluation by breeders and other scientists, a more comprehensive picture can be assembled as to what varieties should be recommended for the region, for what marketing purpose and under what specific management. More often than not, this is the beginning of the industry’s process for figuring out how to grow and manage a new variety, but it is definitely a better starting point than the industry would have without the systematic evaluation of grower trials. As an extension of the breeding program, grower trials are an important investment for the local industry.
Acknowledgements
Collaborating growers and propagators: Michael Dossett (BC Blueberry Council); Mark Sweeney (BC Ministry of Agriculture); Tom Baumann and Zach Fleming (Expert Agriculture Team Ltd.); Tom Peerbolt (Peerbolt Crop Management); Chad Finn (United States Department of Agriculture – Agriculture Research Service); and Pat Moore and Wendy Haoshi-Erhardt (Washington State University).
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Industry Funding
RIDC, BCSGA, BCBC and LMHIA.
Funding Provided By:
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Evaluation of New Products for Weed Control in Raspberry and Strawberry
Tim Miller and Carl Libbey WSU Mount Vernon – NWREC, Mt. Vernon, WA [email protected]
2014 Report: Blueberries
Young ‘Draper’ blueberries, transplanted in September, 2011 (Craig Ford, South Alder Farms, Lynden, cooperator), were treated with directed sprays of Callisto (mesotrione), Prism (rimsulfuron), Sandea (halosulfuron), Sinbar (terbacil), Stinger (clopyralid), Eragon (saflufenacil), Karmex (diuron), Lorox (linuron), Reflex (fomesafen), Alion (indaziflam), Dual Magnum (s-metolachlor), Gramoxone (paraquat), and Velpar (hexazinone) either during late dormancy (early March) or post bud break (late April or early May; POST). The same plots were treated with the same herbicides in 2012, 2013, and 2014. Rows were also occasionally treated with Gramoxone by the cooperator during the summer to control emerged weeds throughout the plots, especially in nontreated control plots. Percent weed control from dormant-season applications was estimated May 7, 2014 and for all plots on May 27, June 23, and August 7, 2014. The experimental design was a randomized complete block with four replicates. Means were separated using Tukey’s HSD (P < 0.05). Data are provided in Table 1.
Some weeds were emerged at the time the dormant application timing. Primary weed species in the plots were common chickweed (Stellaria media), shepherd’s-purse (Capsella bursa-pastoris), purple deadnettle (Lamium purpureum), white clover (Trifolium repens), common groundsel (Senecio vulgaris), spring whitlowgrass (Draba verna), and annual bluegrass (Poa annua). Other weeds included prostrate knotweed (Polygonum aviculare), panicle willow-herb (Epilobium ciliatum), dandelion (Taraxacum officinale), quackgrass (Elymus repens), and corn spurry (Spergula arvensis).
Weed control during this third year of testing did not differ much by these treatments at any evaluation, ranging from 76 to 100%. Most treatments were not significantly different, indicating that these herbicides and combinations were uniformly effective for controlling the weeds in these young ‘Draper’ blueberries. Importantly, no treatments caused visible blueberry foliar injury at any evaluation.
Based on these data, continued testing of these product combinations is warranted. In particular, Eragon and Alion remain as high priorities for registration in nonbearing and newly-planted blueberry, and Reflex also appears to be a good fit for these uses.
Horticulture Growers' Short Course 20 Strawberries/Raspberries
Table 1. Weed control after treatment with several herbicides in third-year ‘Draper’ blueberry (2014). Weed control Treatmenta Rate Timinga May 27 Jun 23 Aug 7 product/a % % % Sandea 2 oz Dormant 86 b-f 79 cd 84 a Stinger 5.3 fl.oz Dormant 88 a-f 86 a-d 86 a Callisto 6 fl.oz Dormant 88 a-f 85 a-d 83 a Prism 4 oz Dormant 93 a-e 81 a-d 85 a Sinbar + Lorox 2 lb + 1 lb Dormant 100 a 96 abc 90 a Sinbar + Lorox 2 lb + 2 lb Dormant 98 abc 86 a-d 86 a Sinbar + Karmex + Lorox 2 lb + 1 lb + 1 lb Dormant 100 a 96 abc 94 a Sinbar + Karmex + Lorox 2 lb + 2 lb + 2 lb Dormant 99 ab 83 a-d 84 a Sinbar + Callisto 2 lb + 6 fl.oz Dormant 100 a 98 ab 95 a Sinbar + Prism 2 lb + 4 oz Dormant 100 a 91 a-d 90 a Velpar + Sinbar + Karmex 1 lb + 1 lb + 1 lb Dormant 99 ab 80 bcd 79 a Eragon + mso + ams 1 oz + 1% + 2% Dormant 88 a-f 79 cd 84 a Eragon + mso + ams 2 oz + 1% + 2% Dormant 80 f 83 a-d 81 a Alion + Gramoxone 2.5 fl.oz + 2 pt Dormant 91 a-e 81 a-d 84 a Alion + Gramoxone 5 fl.oz + 2 pt Dormant 93 a-e 76 d 85 a Reflex 1 pt Dormant 83 def 83 a-d 78 a Reflex 2 pt Dormant 83 def 85 a-d 90 a Reflex + Dual Magnum 2 pt + 1 pt Dormant 94 a-d 85 a-d 86 a Reflex + Callisto 2 pt + 3 fl.oz Dormant 86 b-f 83 a-d 79 a Sandea 2 oz POST 85 c-f 83 a-d 85 a Stinger 5.3 fl.oz POST 76 f 83 a-d 83 a Callisto 6 fl.oz POST 90 a-e 95 abc 93 a Prism 4 oz POST 91 a-e 85 a-d 85 a Sandea + Prism 2 oz + 4 oz POST 91 a-e 91 a-d 90 a Sandea + Callisto 2 oz + 6 fl.oz POST 84 def 91 a-d 85 a Sandea + Stinger 2 oz + 5.3 fl.oz POST 86 b-f 89 a-d 90 a Stinger + Prism 5.3 fl.oz + 4 oz POST 89 a-f 86 a-d 80 a Stinger + Callisto 5.3 fl.oz + 6 fl.oz POST 86 b-f 89 a-d 85 a Prism + Callisto 4 oz + 6 fl.oz POST 90 a-e 99 a 83 a Sandea + Prism + Callisto 2 oz + 4 oz + 6 fl.oz POST 90 a-e 99 a 90 a Sandea + Prism + Stinger 2 oz + 4 oz + 5.3 fl.oz POST 89 a-f 98 ab 89 a Sandea + Callisto + Stinger 2 oz + 6 fl.oz + 5.3 fl.oz POST 89 a-f 95 abc 85 a Prism + Callisto + Stinger 4 oz + 6 fl.oz + 5.3 fl.oz POST 89 a-f 95 abc 86 a Nontreated check ------0 g 0 e 0 b Means within a column followed by the same letter or with no letters are not statistically different (P < 0.05). aDormant applications were made in early March and POST applications were made in late April or early May annually in 2012, 2013, and 2014; all treatments were mixed with nonionic surfactant (0.25%, v/v) prior to application.
Horticulture Growers' Short Course 21 Strawberries/Raspberries
2014 Report: Strawberries
Newly-planted strawberry
Strawberries were transplanted at WSU Mount Vernon NWREC May 16, 2014. Herbicides were applied May 20, 2014 (post-transplant, POSTR); no weeds were emerged at the time of herbicide application. Crop injury and weed control were estimated June 10, July 1, and July 14, 2014. The plots were severely infested with seed from nonharvested buckwheat the previous year, however, so volunteer buckwheat formed a dense growth in all plots throughout the trial. Therefore, postemergence (POST) applications were made June 26, 2014 primarily to gauge impact of the herbicides on that weed, although it was also of interest to look at damage to young strawberry plants. Treatments with POST activity were reapplied, other treatments received Chateau alone (0.75 oz/a + 0.25% nonionic surfactant) as the POST treatment. Given the regrowth of the buckwheat by late July, the experiment was declared complete at that point and plots were tilled. The experimental design was a randomized complete block with four replicates. Data are provided in Table 2.
None of the herbicides applied POSTR had caused visual injury to transplanted strawberries by the June crop injury rating (data not shown). Only after the POST treatments did strawberry show damage. Herbicides applied POST that caused < 15 injury included Spartan (alone or mixed with Trellis or Alion), Reflex (alone or mixed with Devrinol or Dual Magnum), and surprisingly, Eragon + Devrinol (other Eragon treatments caused 30 and 48% injury). It appears that Spartan and Reflex, therefore, may offer the best potential for mid-season applications for weed management rescue operations. Other products resulted in appreciable strawberry leaf damage, although normal new growth was visible in most plots by two weeks after the POST treatment.
Initial weed control ranged from 70 to 95% on June 10, with only Devrinol (70%) or Dual Magnum (73%) providing statistically limited weed control. As mentioned above, poor control of volunteer buckwheat resulted in only about half of the plots showing > 50% weed control by June 26. Weed control after POST herbicide treatments was good to excellent, with all treatments providing at least 83% weed control by July 1. By July 14, Spartan treatments were giving 60 to 65% weed control, Chateau treatments 50 to 70%, Reflex 65 to 90%, and Treevix 60 to 83% at that evaluation (data not shown). Top weed control at that time was observed in strawberries treated with Fierce, Reflex + Dual Magnum, and Eragon + Devrinol.
From these data, it appears that Gallery, Alion, Fierce, Reflex, and Dual Magnum remain excellent candidates for registration in newly-planted strawberry.
Established strawberry
Strawberries were transplanted at WSU Mount Vernon NWREC May 10, 2013. All plots were treated with Spartan + Prowl H2O (5 fl.oz/a + 3.2 pt/a) POSTR for weed control during the establishment year. All plots were also treated with Assure II (quizalofop) October 4, 2013 and Select Max (clethodim) April 28 and/or June 1, 2014 to control Italian ryegrass. The strawberry block was rototilled several times from late summer until winter to maintain weed control between the rows. Plots were treated with dormant- season herbicides January 16, 2014, prior to onset of new growth. Crop injury and weed control were estimated April 9 and May 21, 2014. Berries were picked three times (June 6, 16, and 23, 2014) and marketable berries were counted and weighed. The experimental design was a randomized complete block with three replicates. Crop injury, weed control, and harvest data are provided in Table 3.
Visual strawberry injury coming out of the winter was quite variable, with injury ratings from 0 to 20% in early May, most not differing statistically from each other. By June, there was no visual crop injury from
Horticulture Growers' Short Course 22 Strawberries/Raspberries
any treatment. Weed control was excellent with all treatments by May 3. Reflex alone and Eragon + Devrinol were the only products controlling < 85% of the weeds. By June 6, there was not a significant difference in weed control among all the treatments, which ranged from 78 to 93% control. Neither berry yield not fruit size differed statistically among treatments.
All tested products continue to show promise for use in established strawberry, combining generally good weed control with low crop injury.
Table 2. Weed control and crop injury after application of several herbicides in newly-planted strawberrya (2014). Timingb Weed control Crop injury Treatment Rate Jun 10 Jul 1 Jul 1 product/a % % % Trellis 1.3 lb POSTRc 85 abc 93 abc 45 abc Trellis + Spartan 1.3 lb + 8.5 fl.oz POSTR, POST 85 abc 96 ab 10 e Trellis + Chateau 1.3 lb + 0.75 oz POSTR, POST 81 abc 83 d 39 bc Trellis + Devrinol 1.3 lb + 6 lb POSTRc 80 abc 91 a-d 45 abc Trellis + Dual Magnum 1.3 lb + 1 pt POSTRc 84 abc 95 abc 50 ab Sinbar 6 oz POSTRc 81 abc 95 abc 44 abc Reflex 2 pt POSTR, POST 90 abc 94 abc 15 de Reflex + Devrinol 2 pt + 6 lb POSTR, POST 94 a 94 abc 13 e Reflex + Dual Magnum 2 pt + 1 pt POSTR, POST 94 a 98 ab 13 e Alion 5 fl.oz POSTRc 79 abc 93 abc 40 bc Alion 10 fl.oz POSTRc 86 abc 93 abc 49 ab Alion + Spartan 5 fl.oz + 8.5 fl.oz POSTR, POST 86 abc 95 abc 13 e Alion + Chateau 5 fl.oz + 0.75 oz POSTR, POST 86 abc 95 abc 45 abc Alion + Devrinol 5 fl.oz + 6 lb POSTRc 91 ab 96 ab 44 abc Dual Magnum 1 pt POSTRc 73 bc 91 a-d 45 abc Spartan 8.5 fl.oz POSTR, POST 81 abc 94 abc 13 e Chateau 0.75 oz POSTR, POST 78 abc 93 abc 41 bc Devrinol 6 lb POSTRc 70 c 86 cd 35 bc Fierce 4.6 oz POSTR, POST 95 a 100 a 60 a Eragon 1 oz POSTR, POST 84 abc 91 a-d 30 cd Eragon + Devrinol 1 oz + 6 lb POSTR, POST 91 ab 90 bcd 10 e Eragon + Dual Magnum 1 oz + 1 pt POSTR, POST 91 ab 99 ab 48 ab Nontreated ------0 d 100 a 0 e Means within a column and followed by the same letter or not followed by a letter are not significantly different (P < 0.05). aStrawberries transplanted May 16, 2014; bPOSTR = post-transplant, May 20, 2014; POST = postemergence, May 26, 2014. cPOSTR treatments followed by POST Chateau (0.75 oz/a) + nonionic surfactant (0.25%, v/v) applied May 26, 2014.
Horticulture Growers' Short Course 23 Strawberries/Raspberries
Table 3. Crop injury, weed control, and berry yield after applications of various herbicides during dormancy of established strawberry (2014). Crop Weed Total berry Average Treatmenta Rate injury control yieldb berry May May Jun weightb 3 3 6 product/a % % % g/plot g/berry Trellis 1.3 lb 5 ab 90 ab 85 a 3064 14.3 Trellis + Spartan 1.3 lb + 6.4 fl.oz 13 ab 92 ab 88 a 2537 15.0 Trellis + Chateau 1.3 lb + 0.75 oz 12 ab 90 ab 87 a 2614 14.4 Trellis + Devrinol 1.3 lb + 6 lb 5 ab 88 ab 87 a 3116 14.1 Trellis + Sinbar 1.3 lb + 2 oz 0 b 90 ab 85 a 2169 13.6 Sinbar 6 oz 7 ab 85 ab 82 a 2102 17.0 Reflex 2 pt 5 ab 83 b 92 a 2739 15.1 Reflex + Dual Magnum 1 pt + 1.05 pt 7 ab 92 ab 92 a 3148 15.5 Alion 5 fl.oz 0 b 93 ab 90 a 3446 16.3 Alion 10 fl.oz 7 ab 93 ab 88 a 2508 12.8 Alion + Spartan 5 fl.oz + 6.4 fl.oz 13 ab 92 ab 90 a 2754 16.6 Alion + Chateau 5 fl.oz + 0.75 oz 10 ab 92 ab 87 a 2625 14.4 Alion + Devrinol 5 fl.oz + 6 lb 3 ab 92 ab 92 a 2637 14.9 Alion + Sinbar 5 fl.oz + 2 oz 3 ab 93 ab 93 a 3253 15.7 Eragon 1.44 oz 10 ab 87 ab 82 a 2484 15.6 Eragon 2.9 oz 7 ab 88 ab 87 a 2535 14.5 Eragon + Spartan 1.44 oz + 6.4 fl.oz 10 ab 93 ab 93 a 2788 14.4 Eragon + Chateau 1.44 oz + 0.75 oz 12 ab 92 ab 87 a 2581 14.0 Eragon + Devrinol 1.44 oz + 6 lb 0 b 83 b 78 a 2908 13.4 Eragon + Sinbar 1.44 oz + 2 oz 2 ab 92 ab 87 a 2693 14.6 Fierce 4.6 oz 12 ab 87 ab 80 a 2539 13.1 Fierce + Spartan 4.6 oz + 6.4 fl.oz 17 ab 90 ab 88 a 2267 13.6 Fierce + Devrinol 4.6 oz + 6 lb 8 ab 95 a 85 a 2275 13.3 Fiece + Sinbar 4.6 oz + 2 oz 20 a 88 ab 78 a 1972 14.8 Hand weeded --- 0 b 0 c 0 b 2717 15.1 Means within a column and followed by the same letter or not followed by a letter are not significantly different (P < 0.05). aStrawberries transplanted May 10, 2013; dormant-season herbicides applied January 16, 2014. bBerries picked three times (June 6, 16 and 23, 2014).
Horticulture Growers' Short Course 24 Strawberries/Raspberries
Day-Neutral Strawberries: Recognizing and Managing Insect Pests
Emily Carmichael E.S. Cropconsult Ltd, Surrey, BC [email protected]
Background
There are approximately 70 acres of day-neutral strawberries planted in the Fraser Valley and on Vancouver Island. The main variety grown is ‘Albion’. Day-neutrals are increasing in popularity in BC for several reasons: they provide an opportunity to expand the season past June until the first frost; they are of excellent fruit quality (the fruit is typically large, sweet and firm); and growing them in plastic mulch keeps them clean, which is a desirable trait for the fresh market.
June Bearing vs. Day-Neutral: Differences Contributing to Increased Pest Pressure
Growing day-neutral strawberries differs significantly from growing June-bearing strawberries. There are many differences between June-bearing and day-neutral fields, but several of these differences can be highlighted as key factors that can impact pest dynamics in day-neutral fields.
Factors that can contribute to increased pest pressure in day-neutral fields:
1. Beds are not renovated can lead to increased spider mite and powdery mildew pressure.
The post-harvest mowing (renovation) of June-bearing fields helps both in knocking down spider mite levels and in removing infected powdery mildew leaves. Because day-neutral fields are not renovated, spider mite and powdery mildew levels can really take off, as there is no event that physically removes the disease source or pest host from the field.
2. Grown in raised beds with plastic mulch can lead to increased spider mite pressure.
Another growing practice that can also contribute to increased pest levels is that the plants are grown in beds with plastic mulch. The dark colour of the plastic mulch generates additional heat, which when combined with the summer temperatures, can lead to increased spider mite levels.
3. Bear fruit past June until the first frost can lead to increased thrips, lygus, spider mite, spotted wing drosophila and powdery mildew pressure.
With continual bloom comes flower dwelling pest such as thrips and lygus. As the strawberry season is pushed into some of the hottest months of the year, we see increased pressure from spider mites and SWD. The evening dews and warm days typical of late Aug/Sept encourage the development and spread of powdery mildew.
Horticulture Growers' Short Course 25 Strawberries/Raspberries
Identification and management of 5 uniquely challenging pests of day-neutrals
1. Thrips (Western flower thrips, Frankliniella occidentalis; European flower thrips, F. intonsa)
Why are thrips a problem? • They have rasping/sucking mouthparts. Both adults and larvae feed by removing sap from punctures they make in the plant tissue. • Feeding causes “russetting” or “bronzing” to the fruit surface. As the damaged berries ripen, they turn leathery, dry, and dull in colour. • Damage is observed at low levels in BCat less than 5 thrips/cluster.
Recognizing thrips damage • Damage first appears as small bronze lines on the raised flesh between the seeds. • It often starts at the calyx or hull end of the fruit.
Figure 1. From left to right: beginning of thrips damage on green berry, more established thrips damage on green berry, thrips damage on ripe berry (photos 1 & 2 by S. Busch; photo 3 by C. Teasdale).
Thrips Management • Chemical . Limited spray options; . Delegate is only product registered (1 day PHI and maximum 3 applications per season); . Risk of resistance developing to this pesticide if sprayed repeatedly.
• Biological . Minute pirate bugs and green lacewings will naturally occurring in fields, but they are also commercially available.
• Cultural . Avoid planting strawberries near grass or hay fields, as thrips will move into strawberries when these sites are mowed or dry out.
2. Lygus (Lygus shulli, L. elisus, L. hesperus)
Why are lygus a problem? • They have piercing/sucking mouthparts that they use to puncture individual seeds. • Feeding on seeds causes fruit distortion. • When a seed is damaged, the flesh surrounding the feeding site does not develop properly. • Cause damage called “monkey facing” or “cat facing”.
Horticulture Growers' Short Course 26 Strawberries/Raspberries
Recognizing lygus damage • Poorly pollinated berries and lygus-damaged berries are often confused with each other. • With lygus-damaged fruit, seeds are relatively the same size in the deformed area as compared to the healthy area of the fruit. • With poorly pollinated fruit, the fruit in the deformed area will have smaller seeds compared to the healthy area of the fruit.
Figure 2. Monkey facing/cat facing on green berries (photos by E. Carmichael).
Lygus Management • Chemical . Sprays work best on nymphs, so try to time sprays to target lygus when they are just recently hatched. . Rimon (1 day PHI), Assail (1 day PHI), Clutch (1 day PHI), Matador/Silencer (7 day PHI), Ripcord (7 day PHI), Thionex (7 day PHI), Cygon (7 day PHI), Lagon (7 day PHI), Decis (14 day PHI).
• Biological . Bigeyed bugs, damsel bugs, lacewings and parasitoid wasps are naturally occurring enemies. . None of the enemies are able to prevent economic damage when lygus numbers are high. . Natural enemies may not be present early in the spring when lygus move into the fields.
• Cultural . Good weed managementcontrol weed hosts in winter (where they will lay their eggs). . Host plants including: chickweed, dock, lambsquarters, mallow, lupins, shephard’s purse, brassicas. . Consider proximity of alternate hosts when planting strawberriesadjacent weedy fields and alfalfa plots should not be mowed or disturbed just before or during the strawberry blossom period, because doing so will stimulate movement of lygus into the strawberry fields. . Throughout the season, good weed control within and beside strawberry plantings also helps keep lygus at low levels, but be sure to destroy weeds when lygus are still in the nymph stage and cannot fly.
3. Spider mites (Tetranychus urticae)
Why are spider mites a problem? • Mite feeding on leaves decreases plant vigour and therefore yield. • Feeding damage appears as white speckling on upper leaf surface.
Horticulture Growers' Short Course 27 Strawberries/Raspberries
Spider mite Management • Chemical . Agri-Mek (3 day PHI), Oberon (3 day PHI), Nexter (10 day PHI), Apollo (15 day PHI). . PHIs of the registered products are a limiting factor controlling for this pests with continual harvests.
• Biological . Predator mite release with Amblyseius fallacis or Phytoseiulus persimilis. . Amblyseius fallacis is a native predator mite, best released in spring. . Phytoseiulus persimilis is a heat-tolerant mite that can be released in warmer summer temperatures.
4. Spotted Wing Drosophila (Drosophila suzukii)
Why are SWD a problem? • Female SWD flies lay their eggs in strawberries as they start to ripen. • The larvae are a serious harvest contaminant. • Damaged berries will be soft and leaky as a result of the larval feeding.
Figure 3. SWD larva in strawberry (photo by E. Carmichael).
Management • Chemical . Registered sprays target adults. . Delegate (1 day PHI), Entrust (1 day PHI), Ripcord (2 day PHI), Malathion (3 day PHI).
• Biological . No commercially available biological controls for SWD.
• Cultural . Keep picking intervals short. . Remove culled fruit from the field to eliminate additional feeding and breeding sites.
5. Powdery Mildew (Sphaerotheca macularis)
Why is Powdery Mildew a problem? • Impacts leaves, flowers and fruit. • Infections can reduce pollen production, which will then reduce fruit set, and therefore yield. • Infected green fruit will remain hard and fail to ripen. • Infected fruit will have a bitter taste.
Horticulture Growers' Short Course 28 Strawberries/Raspberries
Figure 4. Powdery Mildew leaf – upward curling exposing purple/merlot discolouration (photo by S. Busch).
Recognizing Powdery Mildew on berries • Infected berries will have a fuzzy white hue. • Seeds will be raised from the surface of the fruit.
Figure 5. From left to right: Powdery mildew starting on green berry, raised seeds on ripe berry caused by powdery mildew, fuzzy white on ripe berry hue caused by powdery mildew (photos from left to right by S. Busch, E.Carmichael and C.Teasdale).
Management • Chemical . Luna Privilege (through drip) (day of harvest), Mettle (day of harvest), Flint (day of harvest), Actinovate (organic) (day of harvest), Regalia Maxx (organic) (day of harvest), Pristine (1 day PHI), Quintec (1 day PHI), Nova (3 day PHI). . Apply fungicides at the first sign of disease (leaf distortion and discolouration). . Repeat sprays at 7-14 day intervals when conditions are conducive to disease development (moderate to high humidity and temperatures between 15 and 27°C).
• Cultural . Destroy old infected foliage. . Avoid excess nitrogen.
Horticulture Growers' Short Course 29 Strawberries/Raspberries
Summary
• Detecting pests early and applying controls at the right time means that you can prevent levels from getting into the danger zone in August and September. • Growing day-neutral strawberries differs significantly from June-bearing in terms of planting methods, length of season and different climate conditions. These all have an impact on pest pressure in the field. • Managing these pests in day-neutrals can be challenging because some of the products available have long PHIs that do not lend well to the short picking intervals. Other products are toxic to pollinators and need to be applied at night. • Regular monitoring throughout season improves ability to control these pests and maintain fruit quality
The chart below shows the increasing pest pressure as harvest continues into August and September.
Deeper red = higher risk * = when to start monitoring
Horticulture Growers' Short Course 30 Strawberries/Raspberries
2015 Processed Red Raspberry Market Outlook
Jen Dhaliwal Pacific Coast Fruit Products Ltd., Abbotsford, BC [email protected]
2014 Season Review
As most of you all know, last season was a very productive season. The quality of the 2014 harvest was again very good. It was a bit nerve-wracking at the start of the year with all the winter damage we were seeing throughout BC and WA. However, the weather co-operated and the plants seemed to bounce back. It was very sporadic. I saw as much at 40% loss in some fields, whereas others were left virtually untouched. Overall, the harvest was better than we expected.
There was lots going on in the production side of thingsmore IQF tunnels went in, and more and more people were packing IQF. This is a very good thing to see, as we need to maintain a healthy balance in the market. It is a basic supply and demand situation. If you have an excess of one pack-style, then you will drive the market price down, and vice versa. Too much of one thing is never a good idea.
In addition to fantastic weather conditions, we were very pleased to see that we had low SWD counts coming in with the fruit, especially compared to 2013! I encourage everyone to please keep on top of your spray program and ensure you speak with your packer and processor regarding what chemicals they wish you to use, or not use. There was some confusion about the use of Ripcord that was registered in Canada, but with the MRL so low that we were not able to use it. Be careful with your sprayer! Health Canada is working to get the MRL’s consistent with Codex, but this is going to take time!
Keeping the SWD away not only protects our raspberries, but it also protects our blueberries and keeps our blueberry packers happy.
Pricing increased substantially in 2014 from the 2013 crop; part of this is due to low inventory at the beginning of the season
PCFP lbs Received by Date
Fresh quality was good. The weather held out and IQF packers were able to maximize their production. There were a couple of times I can recall, when some IQF processors had to turn away fruit because they were too busy to pack it all. Throughout the season, we had a fairly steady flow of fruit coming in, but there were some substantial drops and spikes. We were all scrambling from time to time, but we were able to provide homes for all of our wonderful raspberries.
Comparison of Raspberries Received by Date 2013 - 2014
Our harvest lasted 38 days with a couple of drums trickling in here and there. It is interesting to see the difference between how the fruit was coming in during 2013, and how it was received in 2014. A large part of this was due to the weather. We had dry sunny conditions and everyone needed to maximize IQF production, which is great. Then we had a couple of days of rain when very few people picked, and then we were back to the super dry heat again. At one point, it was so hot and dry that I don’t think anyone could predict what the fruit would do.
Horticulture Growers' Short Course 31 Strawberries/Raspberries
PNW Raspberry Production
The production out of the Pacific Northwest as a whole was approximately 92 million lbs, with BC contributing to a little over 16 million of that. Production was very similar to 2013, with only a slight increase.
PNW Plant Sales
Plant sales have increased slightly. 40% of plant sales were of the ‘Meeker’ variety and 30% of plant sales were ‘Wakefield’.
It is interesting to notice how plant sales had a spike in 2009 after grower price increased dramatically in 2008, nearly clearing out nurseries everywhere. As much as we would love to see this increase happen again, we are unfortunately still losing acres of raspberries to blueberries.
US Red Raspberry Holdings
Cold storage holdings are down slightly this year at 58.5 million lbs from last year’s 62 million lbs. Most of the current inventory is either committed or sold, leaving little as a cushion as we move into 2015.
Cumulative Raspberry Usage
As of the end of November, holdings appear to be down while raspberry usage is on the rise. Raspberry usage was up 15-20% over last year. This is a good thing from a sales perspective. However, if inventory is low and usage is up we want to keep our fingers crossed that we have a good harvest in 2015.
Worldwide Processed Raspberry Production 2014
In the Fraser Valley we have some wonderful land, great growers and various levels of government support, but we are still small players on the global market. We are seeing some competition from Mexico. They have cheaper land, more affordable labour, grow according to US pesticide restrictions, and have a free trade agreement with the US.
Other Regions
Europe has been in a situation of bad or good, depending on how you look at it. Overall production has increased from 2013 but weather has plagued the region with quality issues.
Poland had quality issues with texture, size, and brix. This resulted in even lower numbers of Grade ‘A’ fruit than expected.
Serbia experienced extensive rainfall in the spring and flooding in harvest, which again created quality issues. One of our business associates with a facility in Serbia told us they couldn’t get fruit into the plant, because many of the local roads were just a swamp and farmers had to detour miles around to get there. IQF production was down 20%. Keep in mind that since Serbia does not grow to US pesticide requirements, this fruit will not be destined for North American markets.
This shortage of IQF raw material has caused there to be a much smaller price gap between IQF and crumbles. It is estimated that this is a temporary situation, and moving forward, the price gap should return to a more normal level.
Horticulture Growers' Short Course 32 Strawberries/Raspberries
Chile
The second bloom of ‘Heritage’ has just begun, so it is still a little too early to give any real firm numbers out of Chile.
Initial predictions are that the crop will be relatively the same as last season, which is down from 2013, and much like in Canada, raspberries are losing acres to blueberries.
The low Chilean peso is boosting exports into the US and the demand is strong. Pricing is expected to remain solid.
Opening IQF pricing is around USD 2.00 – 2.20 lb for GFSI certified plants and USD 1.90 for smaller plants.
Chilean growers are currently receiving around USD 0.75/lb for good quality juice stock.
Market Influences
When doing my research and writing my speech, it was very difficult to come up with any negatives. We are in a really great position right now regarding the raspberry market. If I had to list something as a negative, I would say that we should consider the high selling prices as a potential risk. If pricing climbs too high, as it did in 2008, we run into the situation where our customers simply drop raspberry from their program. We need to be mindful of this as an industry, because once the sales are gone and consumers are used to a different fruit profile, it is very hard to get this business back.
I would also like to just quickly mention that SWD still remains an ever-present risk. Although it was a good season in 2014, we still need to protect ourselves in 2015.
And as we all know, the weather is always a potential risk. Do you think we can possibly get three great seasons in a row? Let’s hope so!
Now, on to the positives...
One of the biggest impacts on our market year after year is current inventory. This year, inventory is low. Having little inventory to carry over into the new crop already places our raspberries in demand.
Usage is up! This is exciting news!! It has taken us several years to bounce back from the past 5-6 years of low raspberry usage and it should continue to be the trend for 2015.
As stated previously, Chile’s crop is expected to be low again, leaving us Canadians, the last ones in the race, room for exporting.
Last, but not least, the US Dollar...
Now as Canadian processors and packers, the US exchange is an ever-present concern. The good news is the US dollar is up and the exchange rate is high. This might not be such great news if you are crossing the border for gas and milk, but in the raspberry industry it only helps us to increase our sales. We grow, pack, and process in CAD funds and sell primarily in US funds. This gives us a competitive edge when the US dollar is up.
Horticulture Growers' Short Course 33 Strawberries/Raspberries
Market Outlook for 2014
Grower pricing for 2014 is expected to finish at around 1.20-1.25/lb for washed puree or straight-pack puree stock.
It is great news for the growers who have been struggling with such low prices. We need to make sure that we continue to diversify our pack styles in order to have an even balance in the market.
We do expect strong prices to continue into 2015.
Horticulture Growers' Short Course 34 Greenhouse Vegetable
To Fog or Not to Fog: That is the Question
Mark Stanley MicroCool, Thousand Palms, CA [email protected]
High-pressure fog systems can be used to humidify and cool greenhouse environments. Mark will discuss the use of fog systems to optimize environmental conditions around the plant to maximize plant growth and crop yield.
This presentation will explain the operation and use of a high pressure water fog system in greenhouses and offer growers some insight into improving the operation.
Droplet Size
Fog systems are used all over the world, but a better understanding of how and why fog systems work will assist growers in obtaining the best results from the system.
The droplet size produced by fog systems is approximately 10 microns (1/10th the diameter of a human hair). The water only evaporates from the surface of the droplet.
Larger droplets sizes have a much lower surface area to volume ratio. The smaller the droplet, the faster it will evaporate into the releasing the energy.
The change of state from a liquid to a gas provides an adiabatic cooling effect that cools the air around the droplet; it will also add moisture to the air and increase the relative humidity of the air around it. Billions of droplets are evaporating every second, allowing the surrounding air temperature to decrease. The cooling power of one nozzle is equivalent to approximately 1 ton of air conditioning.
Weather Data
Weather data analysis using local information or that garnered from www.wunderground.com helps to understand what is possible in any particular situation. It is noted that in many cases the high temperature and the high humidity are offered as an indication of a local climate.
The illustrations noted that in most cases when the high temperature is reported, this is also when the humidity is at its lowest. Cooling is only required when the greenhouse is too hot; by using the low humidity value at this point, maximum cooling can be achieved in the greenhouse.
Horticulture Growers' Short Course 35 Greenhouse Vegetable
Examples of different days and specific conditions were presented to illustrate the phenomenon. Cooling potential and water required to change the condition of the air can be calculated using a simple psycrometric chart.
Examples of how relative humidity can affect the cooling potential were shown. With a higher humidity there is less “room” in which to evaporate the fog. Higher humidity levels also slow down the speed of the absorbsion in the surrounding air.
Greenhouse cooling requires a change of air to effect maximum cooling; once a volume of air has been cooled, it must be exchanged for a second volume of drier air tor “treatment”. This air change is achieved using mechanical or natural methods.
Greenhouse Climate Control (“Your Fog system is only as good as the system that controls it.”)
If the fog is left uncontrolled, the humidity level will rise until the air is saturated. No cooling is taking place when these levels are reached. At high humidity levels the plants in the greenhouse will also suffer, as the difference in pressure does not allow transpiration from the leafnutrient uptake can also be affected. Settings are determined by the grower, but are commonly between 55% and 65% RH.
The controller measuring the temperature and humidity of the air will then interrupt the signal to the fog equipment until the humidity levels have decreased. When below a set level, the system will resume operation, lowering the temperature and affecting the humidity. Since the air coming into the greenhouse is always changing, these levels produce different operational sequences and also the amount of possible cooling. The controller effectively manages the temperature of the greenhouse on the humidity setpoint. When the fog is operational, different vent strategies are used to ensure that the greenhouse air exchange is kept at an optimal rate to optimize greenhouse cooling.
It is of paramount importance that the control of the fog system be integrated with the central climate controller. The fog system is changing the environment inside the greenhouse and other factors and operations will be influenced by these changes.
Differing nozzle densities are used when selecting either a cooling system to a humidification system. Since the cooling operation requires many air changes, the density of fog nozzles is much greater.
Water Quality
Water supplies with a high mineral content and/or organic content cause numerous problems with fog systems. Nozzle orifices are 0.008” or 0.2mm in diameter; if unsuitable water is used in the system the nozzle flow will reduce, diminishing the cooling potential of the system. It is similar to shutting down 50% of a building air conditioning and expecting the same result.
Horticulture Growers' Short Course 36 Greenhouse Vegetable
High levels of minerals in the water can also slowly block the nozzles as they precipitate. These minerals are also left in the air when the water flash evaporates. These particles are in the molecular level at 0.001 – 0.0001 microns so cannot easily be removed with simple filtration. The minerals also collect on the leaves (reducing transpiration) and the fruit (reducing quality). Many treatments are available, but the most effective is Reverse Osmosis, which remove all the minerals as well as other impurities (see diagram).
Reverse Osmosis systems work by forcing the water through multiple membranes to remove mineral salts and impurities.
Ultraviolet lights are also installed in critical operations. These bulbs, installed on the low pressure side, will remove 99.9% of the bacteria and viruses in the water. Should there be a problems with the RO unit, the UV light ensures continued sterilization of the system water.
The presentation concludes with an insight to new devlopments in the humidification and cooling arena. MicroCool uses Variable Frequency Drives on the motors to reduce electrical usage and wear on the motors and pump heads. The latest developments in PLCs and display screens inform the user on usage and time to replace filters and oil. They can also be connected to external units to provide remote monitoring.
The latest development in nozzle technology was demonstrated with the MicroCool FOCUS range of nozzles that include an individual solenoid for each nozzle (or nozzle unit). The nozzles operate and shut instantly, removing the chance of any drips or wetting in critical areas.
Horticulture Growers' Short Course 37 Greenhouse Vegetable
Strategies for Biocontrol of Aphids in Greenhouse Vegetable Crops
Gerben Messelink Wageningen UR Greenhouse Horticulture, Bleiswijk, The Netherlands [email protected]
Biological control in sweet pepper has been one of the success stories of the greenhouse industry for decades. This success is mainly based on inoculative releases of anthocorid predatory bugs and generalist phytoseiid predatory mites, which successfully control thrips, broad mites and whiteflies. One of the last obstacles for a completely pesticide-free cropping system are aphids. Sweet pepper in particular is often quickly damaged by aphids, mainly by the peach aphid Myzus persicae (Sulzer), the foxglove aphid Aulacorthum solani (Kaltenbach) and the cotton aphid Aphis gossypii (Glover), because of their extremely fast development in this crop. Biological control of these pests in sweet pepper is difficult and expensive, as effective control requires repeated releases of natural enemies. So far, aphid control strategies are mainly based on frequent releases of specialized aphid parasitoids and the predatory midge Aphidoletes aphidimyza (Rondani). Additionally, growers release chrysopid, syrphid or coccinellid predators to suppress high aphid densities. However, none of these natural enemies is able to establish in a crop without aphids. Biological control of aphids might be greatly improved by generalist predators that are able to establish in a sweet pepper crop prior to aphid infestations, because this can result in rapid responses to new aphid infestations and prevent establishment of aphids.
Wageningen UR Greenhouse Horticulture has tried to develop new strategies for aphid control based on generalist predators, parasitoids and measures that prevent disruption by hyperparasitoids or hyperpredators. I summarize the main conclusions of these studies.
Generalist Predators
• We studied the effects of inoculative releases of the generalist predatory bugs Orius laevigatus, Orius majusculus and Macrolophus pygmaeus on green peach aphids and western flower thrips in a greenhouse grown sweet pepper crop. We found that compared to the two Orius species, M. pygmaeus was by far the best predator for controlling aphids. Similar results may be achieved with Dicyphus species. • Intraguild predation of M. pygmaeus by O. laevigatus did not affect coexistence of the two predators. • The combined use of the 2 predators M. pygmaeus and O. laevigatus gave the best control of both thrips and aphids.
Parasitoids
• Aphidius matricariae is more effective against peach aphid than Aphidius colemani. • Efficacy of A. matricariae is reduced in the presence of an unsuitable host (foxglove aphid), thus we recommend the release of “generalists” such as A. ervi when different aphid species are present. • Aphidius ervi is more effective in searching out aphid colonies over larger distances. • Aphidius colemani seems to do better at lower light conditions than A. matricariae (indications searching experiment).
Horticulture Growers' Short Course 38 Greenhouse Vegetable
Hyperpredators and Hyperparasitoids
• Hyperparasitoids can completely disrupt biological control with primary parasitoids, as hyperparasitism rates can go up to 100%. Abundant hyperparasitoids in The Netherlands are Dendrocerus aphidum and Asaphes suspensus. A survey among growers suggested that the hyperparasitoids overwinter in greenhouses. It is therefore recommended not to use banker plants with aphid mummies early in the season, as this can facilitate the establishment of hyperparasitoids. • We evaluate the impact of three species of generalist predatory mites on the biological control of green peach aphids, Myzus persicae with the aphidophagous gall midge Aphidoletes aphidimyza. The predatory mites tested were Neoseiulus cucumeris, Iphiseius degenerans and Amblyseius swirskii, which are all commonly used for pest control in greenhouse sweet pepper. All three species of predatory mites were found to feed on eggs of A. aphidimyza, even in the presence of abundant sweet pepper pollen, an alternative food source for the predatory mites. In a greenhouse experiment on sweet pepper, all three predators significantly reduced population densities of A. aphidimyza, but aphid densities only increased significantly in the presence of A. swirskii when compared to the treatment with A. aphidimyza only. We therefore recommend not to use A. swirskii for thrips control when the biological control of aphids with A. aphidimyza is more important.
References for More Background Information
Messelink, G. J., C. M. J. Bloemhard, J. A. Cortes, M. W. Sabelis, and A. Janssen. 2011. Hyperpredation by generalist predatory mites disrupts biological control of aphids by the aphidophagous gall midge Aphidoletes aphidimyza. Biological Control 57:246-252.
Schelt, J. v., H. Hoogerbrugge, N. Becker, G. Messelink, and K. Bolckmans. 2011. Comparing Aphidius colemani and Aphidius matricariae on Myzus persicae ssp. nicotianae in sweet pepper. IOBC/wprs 68:169-172.
Messelink, G. J., C. M. J. Bloemhard, L. Kok, and A. Janssen. 2011. Generalist predatory bugs control aphids in sweet pepper. IOBC/wprs Bulletin 68:115-118.
Messelink, G., C. Bloemhard, H. Hoogerbrugge, and J. Van Schelt. 2012. Evaluation of four lacewing species for aphid control in sweet pepper. IOBC/wprs Bulletin 80:149-153.
Messelink, G. J., M. W. Sabelis, and A. Janssen. 2012. Generalist predators, food web complexities and biological pest control in greenhouse crops. Pages 191-214 in M. L. Larramendy and S. Soloneski, editors. Integrated pest management and pest control - current and future tactics. InTech, Rijeka.
Messelink, G. J., C. M. J. Bloemhard, M. W. Sabelis, and A. Janssen. 2013. Biological control of aphids in the presence of thrips and their enemies. BioControl 58:45-55.
Messelink, G. J., and A. Janssen. 2014. Increased control of thrips and aphids in greenhouses with two species of generalist predatory bugs involved in intraguild predation. Biological Control 79:1-7.
Horticulture Growers' Short Course 39 Greenhouse Vegetable
From the Depths of the Earth to Your Customer’s Kitchen
Alison Thompson Canadian Geothermal Energy Association, Calgary, AB [email protected]
The direct use of geothermal heat refers to any non-electric applications of geothermal resources. Any application that requires heat can use geothermal direct use. The most attractive of these are agricultural applications, including: greenhouses, soil warming and sterilization, milk pasteurization, and food drying and processing. Using a renewable heat source not only reduces the carbon footprint of an operation that otherwise would use fossil fuels, but it may also cut costs. Compared to not utilizing a heat source, geothermal heating practices can improve yield and efficiency. The diagram below shows the many opportunities available through the direct use of geothermal heat.
If you think this sounds like science fiction, other countries are already using geothermal heat to support agricultural production. Agricultural and floral crops are successfully grown in Hungary, Russia, New Zealand, Japan, Iceland, China, Tunisia, Kenya, and the United States. Iceland, for example, is a northern country like Canada, which produces 90% of its cucumbers, 75% of its tomatoes, and large portions of its peppers and small fruits are produced in geothermal heated greenhouses.
Horticulture Growers' Short Course 40 Greenhouse Vegetable
Other agricultural applications of geothermal heat include soil warming and sterilization. Soil warming involves running pipes beneath crop fields and circulating geothermal waters through them to heat the soil prematurely to begin the growing season early. It should be noted that by doing this, certain crops can be brought to market earlier and thus demand a greater price than they normally would.
Soil sterilization can be performed in a greenhouse or in a field and involves using hot geothermal waters to kill bacteria and fungi that infect plants, which reduces the need for chemical pesticides. This has many benefits to ecological and human health.
Additionally, geothermal heat can be used to process food products, providing a final product ready for sale in the BC market or for export. This includes drying fruits, vegetables, and herbs to be used in numerous food products. These could serve as new entrepreneurial opportunities in BC.
Local food production is significantly important to BC consumers, as they rely on imported food crops from California. In 2010, BC imported 67% of its vegetables from the US; more than half of that was from California. Due to the impact of recent droughts on crop yields in California, the price of food is expected to rise between 20% and 34%, which will directly affect the household budgets of British Columbians. However, using geothermal heat for greenhouse production could reduce this impact by increasing local food production. Geothermal is a renewable, cost-effective heat source that can lengthen the growing season, improve efficiency by regulating temperatures, and reduce transportation distances, as well as providing new entrepreneurial opportunities. Purchasing food locally strengthens the local economy. A Vancouver City Savings Credit Union’s study found that if the average BC household were to spend 50% of its grocery budget on local food, up to an extra $6,457 per household would circulate in the local economy.
Producing local food is especially important in Northern and Remote Communities, where the growing season is short and transportation costs are higher. Especially because many Aboriginal communities are experiencing what has been deemed a ‘nutrition transition’ from traditional foods to industrial, processed foods. This has led to a rise in non-communicable diseases such as diabetes, heart disease, and cancer. Increasing the amount of food that can be grown locally allows healthy fruits and vegetables to be produced for a longer growing season and makes them available at a lower cost than expensive imports. The controlled, local production of fruits and vegetables that are not subject to unpredictable events such as those influenced by weather also ensures price stability and a steady, reliable supply of healthy foods.
There are many uses for geothermal heat in agricultural production that offer significant benefits that will increase food security and independence in BC. As we like to say at CanGEA, the applications for direct use of geothermal heat are limited only by your imagination.
Alison Thompson’s Biography
As one of Canada’s foremost champions of geothermal energy, Alison Thompson is paving the way for the Canadian energy sector to capitalize on a large, untapped resource of renewable energy. From 2007- present, Ms. Thompson took the reins as Managing Director and remains as Chair of the Canadian Geothermal Energy Association (CanGEA), where she is building this non-profit organization into a respected and influential assembly of industry representatives advocating for the development and commercialization of Canada’s geothermal energy resources.
Horticulture Growers' Short Course 41 Agro-Forestry/AlternativeGreenhouse Vegetable Crops
Cold Climate Food Forest Agroforestry
Michelle Heinz Clear Sky Meditation and Study Foundation, Fort Steele, BC [email protected]
In 2013, thanks to funding from the Agro-forestry Industry Development Initiative (AIDI), Clear Sky completed planting of the first one-acre cold climate food forest in Canada. Today I will share how it came to be, its design, how it’s doing, and where it is headed next.
Firstly, Clear Sky is a retreat centre in southeastern British Columbia - a non-profit, charitable organization and LEARNING pioneer founded in 2004. Clear Sky gives people tools and opportunities to make LASTING changes in their day-to-day experience of life, inspiring full engagement and life-long learning. We practice this in many ways, such as by providing courses in (and role-modeling) sustainable agriculture, permaculture, food forestry, green building, and ecological restoration. Clear Sky is located between Fernie and Cranbrook, 20 minutes from Fort Steele Heritage town and 5 minutes from the Kootenay Trout Hatchery. It sits on a breathtaking 310 wooded acres in the Agricultural Land Reserve (ALR) and within a precious wildlife corridor, connecting Yellowstone to Yukon (Y2Y).
Did you know that grasslands comprise less than 1% of BC's land base, and are home to more than one- third of BC's endangered and at-risk species, according to BC Grasslands? Of all of BC's grasslands, those in the East Kootenays are under the most serious pressure. Main issues include human settlement and development, disruption of the natural fire cycle / forest ingrowth, invasive species, and unsustainable management practices. This alone has motivated us to find more sustainable ways of living and supporting our precious land.
Why a food forest? In 2007, I was managing the land at Clear Sky and was only on-property for 2 months of the year. In my attempts to find a cold-hardy crop that required little water and care, I discovered a plant called sea-buckthorn, a super food from Eurasia. I also discovered an organic grower, Richard Walker, in Grand Forks that I spoke with on the phone. In April 2008, en route to relocating to CS and to plant sea buckthorn, I drove through Grand Forks and gave him a call. Over tea I asked Richard what he did and he said, let me show you. That was my first introduction to a food forest, and it changed my life. From a hayfield, Richard had designed and managed a 3.5 acre food forest from the ground up. I experienced the fruits of his labours and knew it was possible. I had no idea at the time that he had pioneered food forests in Canada, and that 5 years later he would be part of designing a one acre cold climate food forest at Clear Sky. Clear Sky wanted to create a demonstration model food forest to see how agro-forestry could offer more sustainable opportunities for growing local food security, revenue generation, contributing to ecosystem health and well-being. Agro-forestry is outside of the box for the traditional ranching community in which we live.
So what is a food forest? It is an intentional garden designed to mimic a forest’s structure and function. This includes producing food, fuel, fibre, fodder, fertilizer, medicinals. And it’s fun!
What are the features of a food forest? Multiple canopy layerings, high diversity, beneficials and pest control, pollination, a full season of multiple harvests, soil building, no tillage, self-fertilizing, less inputs / fossil fuels, less water used, quality soil producing quality food, multiple high quality harvests from snowmelt to snowfall, fruit, nuts, herbs, vegetables, medicinals, herbal tinctures & teas, fruit wines, preserves, nursery business, propagation and, last but not least, the farmer's goals are at the centre of the system.
Horticulture Growers' Short Course 42 Agro-Forestry/Alternative Crops
The Clear Sky site is in zone 4, with mountainous conditions and low rainfall, with a 25 acre elk-fenced field previously in hay and of moderate fertility. It gets wind from all directions, is south facing with good sun exposure and has access to well water or mountain stream irrigation.
Working with Richard Walker and Leslie Lowe (a landscape architect), we created an oval design to match the local surroundings, with 5 rings and a buffer. The buffer zone contains trembling aspen, Amur maple, Saskatoons, filberts, haskaps and lilacs. This zone will grow fast and offer some wind protection and aid in capturing solar. Within the buffer zone are 5 rings. Circle 5 contains the canopy trees: trembling aspen, lindens, burr oak, with room for annual crops/covers between. We have grown heritage garlic. In circle 4 we start to move to smaller trees with nanny berry, willows, black locust, hawthorn, European mountain ash, caragana, box elder and linden.
Circle 3a leads us into shrubs and berries such as filberts, sea-buckthorn and currants and the inside of the 3rd row are plums, pears, lilac and cherry. Row 2 contains various cherries and a Siberian salt tree. The inner circle is home to herbaceous material, vines such as grapes, kiwi, and further small shrubs and fruit bushes like chokecherry, haskap, currant, Saskatoon, raspberry, blueberry, goji berry, gooseberry and about 500 asparagus plants.
The herbaceous layer includes asparagus, chives, dill, horseradish, orach, borage, sea kale, arugula, Jerusalem artichoke, lemon balm, daylily, Solomon's seal, salad burnet, sorrel, skirret, thyme and ostrich fern. Given the opportunity to include native forbs and grasses, we did, and our inventory includes heart- leaf, arrowleaf balsamroot, showy aster, flat-top spirea, silky lupine, rough fescue and prairie junegrass. Medicinals include: astragalus, poor man’s ginseng, echinacea, Siberian ginseng, stinging nettle, golden seal, motherwort, mallow, mints, catnip, goldenrod, allheal and valerian.
So how is fertility increased? Constant leaf fall, recycling by deep accumulator plants and nitrogen fixation contribute to a growing level of humus and biological diversity over time. High humus soil can maintain far higher levels of both nutrition and water, thus dropping the need for irrigation and fertilization in the future. Examples also include beneficial and native species reducing disease and insect problems.
Wild Connectivity
We aim to have linkages from the wild areas outside the fence to the buffer zone, leading to and from the food forest circle, to provide a corridor for beneficial and native speciesplants, insects and birds. We are already seeing healthy communities of busy native bees. Sand beds provide nesting sites for many of the beneficial wild bees. Woody material works well for providing habitat for many species of ground beetle. High plant and native species diversity extends the flowering season. Fortunately we have several Jeffersonian badgers on our property (there are only 200 odd in the province), and they manage rodents for us, while staying out of the food forest. In 2014 we installed electric fencing around our food forest to protect local bears, our neighbours, the food forest and ourselves.
Estimated Yields in 5 Years
600 lbs of Saskatoon from 30 trees, 300 lbs of haskap berries from 20 bushes, 200 lbs of cherries from 30 trees, 200 lbs of raspberries from 100 canes, 30 lbs of gooseberries from 10 bushes, 70 lbs of blueberries from 12 bushes, 150 lbs of sea-buckthorn berries from 10 thornless sea-buckthorn trees, 1500 lbs of apples from 20 apple trees, 600 lbs of pears from 12 trees, 600 lbs of plums from 15 trees, 800 lbs of choke cherries, 300 lbs of hazelnuts from a few small groves, 100 lbs of currants from 12 bushes, 25 lbs of goji from 5 plants, 50 lbs of kolomitka hardy kiwis from 5 vines, 175 lbs of grapes from 8 hardy vines. Herbaceous and early vegetables include 750 lbs of asparagus per year. Small early and late season
Horticulture Growers' Short Course 43 Agro-Forestry/Alternative Crops
harvests of perennial and often unusual gourmet vegetables include chives, sea kale, specialty mints, linden leaves, sweet cecily, daylilies, edible flowers, Jerusalem artichokes and ostrich fern.
Please remember that we are demonstrating substantially improved yields for difficult cold climate production, which otherwise would be producing an extremely limited selection and volume of food. This is partly done by selecting cold hardy species and carefully placing them within the system to perform various functions and mutually beneficial relationships with other plants. It is a science and an art to create a community of beings, empowering nature to work together and to reduce human inputs. One example of this is with a buffer zone and 5 rings. In 10-20 years, the middle area will be one zone warmer than outside the food forest because we are co-creating a micro-climate. Another example is for every tree we planted, we also planted with it caragana (Siberian pea shrub) to fix nitrogen directly into the ground. As it grows it can be cut back and added to the mulch layer.
Other income stream potentials
There is also income from nursery and seed sales for fruit, berries and nuts, insectary plants & seeds (pollinators) for cold climates, eco-tours and educational opportunities for local schools, varieties of medicinals for cold climates, native forbs and grasses seed mixes, soil improvement plants such as sterile comfrey ‘Bocking 14’, and sorrels. There is a wide range of potential value-added products from various berries & fruit (e.g. juices, syrups, vinegars, wines).
Since we planted, we have already hosted over 30 tours and begun to enjoy the harvests. In late 2013, we began working on a feasibility study to see how we can effectively bring various yields on a relatively small scale into production. On a regular orchard you can harvest simply, if all the plants are the same. In this case we are harvesting different plants at different times and in different ways.
Are you asking, “How do you do it all?” Can you increase your bottom line, find time to spend with family and also support healthy ecosystems? We believe we can. To that end, we are hosting a workshop in our local community at the end of February, to craft a holistic goal from which we can base decisions moving forward in order to meet our quadruple bottom line. Jeff Goebel is a certified holistic management educator and international consensus builder. He specializes in leveraging issues which can accelerate and lead to the long-lasting and effective changes we want, which includes healthy financial returns, a lifestyle that is sustainable and eco-systems that are vibrant. Please contact Michelle at [email protected] to find out more about our food forest, courses and centre.
Horticulture Growers' Short Course 44 Agro-Forestry/Alternative Crops
Cariboo Silvopasture: Zirnhelt Ranch
David Zirnhelt Zirhelt Ranch, Beaver Valley, BC [email protected]
Zirnhelt Ranch is located in Beaver Valley near Big Lake in the eastern part of the Cariboo. Precipitation is 22 inches. Rarely is irrigation needed for forage crops on a single crop basis. Elevation is 2280 feet. Aspect is a Northerly slope. The ranch is a combination of an older ranch dating to the 1920s and added to over the years since 1974. The demonstration site is 140 acres.
Zirnhelt Ranch has a biodiversity plan which calls for introducing more biodiversity into the monocrop hay and pastureland uses. Given the large area of Riparian zones, plans call for judiciously grazing those areas.
The ranch consists of 644 acres of private land, 1500 acres of crown woodlot license, and thousands of acres of open range. The range and woodlot are shared with the neighbouring ranch (once part of a previous private land partnership).
About 60% of the deeded land base is forest, including silvopasture, whereas the cultivated perennials forage cropland is only 21%. This means that the ranch as a unit, especially in conjunction with associated crown land, is significantly biodiverse.
The silvopasture demonstration (140 acres) is a significant past on the land use and associated biodiversity objectives. The history of this lot (Cariboo District lot 8240) involves preemption by a homesteader who raised mink and sold to a fish and game guide (Fairchild) who mainly pastured his horses used for guiding hunters seeking big game (moose, deer, cougar, bear).
Before it was severely logged between 2003 and 2005 it had been partially logged (selectively logged, i.e. selecting the biggest and best trees and logging them down to an 18 in diameter) and the logs milled on site.
Zirnhelt Ranch pastured horses there for several years in the 1980s and utilized up to 80 AUMs (Animal Unit Months: one AUM is one 1000 lb. cow and calf for one month grazing). Zirnhelt Ranch bought the lot in 2005 for pasture and a potential homesite for a family member. The idea was to try to keep in a savannah like state for grazing and recreation. The previous owner logged virtually all the land which could physically be accessed and took almost every hardwood and softwood tree over the 20 cm size which was saleable.
Management Objectives for the Ranch
The first objective is to double the amount of forage for cattle for a pasture finishing beef operation. Second, management must maintain and enhance biodiversity. Third, the cattle should be adapted to the land as well as the land to the cattle. Fourth, cows are the main implements of landscaping to achieve the objectives. Fifth, the silvopasture is to be used eventually as part of the finishing operation for direct marketing of grass fed and finished beef.
Horticulture Growers' Short Course 45 Agro-Forestry/Alternative Crops
Silvopasture
The 140 acres are divided into three equal management units each containing some of the two ecological associations in the area: one, the moist hot Sub-boreal Spruce biogeoclimatic subzone, and two, the drier, warm Sub-boreal subzone.
The “Control” management unit is to utilize cattle only to effect the development of more forage. The “Silvopasture” unit calls for spacing trees and making forage improvements through limited land development; removal of some course woody debris, scarification for seed for seed catch of agronomic forage species. The third management unit, “Pasture”, involves developing the land by stumping and clearing, are vigorous scarification for predominantly domestic forage cover: improved pasture.
The original prescription called for brushing deciduous trees and shrubs, removal of slash, spacing of crop trees (softwoods, fir, pine, spruce) to 350 stems per acre (5 meter spacing), scarification and seeding of agronomic forage species.
Because of the high cost of contracting this work out, a revised prescription was created by consultation between the original pilot designer, the contractor, and the owner. This new prescription would see the creation of minimally bladed and slashed trails or corridors to facilitate cattle movement so cattle trampling and grazing would open up areas covered in brush. Cattle were to graze intensively at high stocking rates for short periods – one to three days – and in the process spread seed, fertilize and “cultivate” sufficiently for establishment of agronomic species . Infrastructure Improvements
Electric fencing of the three management units with a single strand high tensile steel wire fence was undertaken using treated wooden posts for corners and gates and plastic post in between.
Three water sources were to be developed in addition to a controlled access on the lake edge. Two springs are to be fenced and water piped to troughs. One dug out has been built to store spring runoff. Additional corridors, approximately 10 per management unit were to be developed to make it easier to cross fence the units further for the intensive grazing Management of smaller areas.
Cost Trials
Small areas of slashing were hand piled and costed. Another area was machine piled and scarified in the processing an excavator with a rake attachment to get a scarified site.
Cost Benefit Analysis
The capital cost needs to be low ($26,000) in order for there to be a positive return. Annual costs need to be low. A positive cashflow happens with stocking of 66 head of cattle (double the current 33 head). Cash flow and margins become greater when forage is suitable for finishing and direct marketing of the beef.
Cattle Management
Cattle are put on the silvospasture in late winter and feed using a bale grazing method: round hay bales are placed on patches of thick brush so the cattle can trample the brush area and fertilize the ground and promote more forage growth. Holistic Resource Management principles are used:
Horticulture Growers' Short Course 46 Agro-Forestry/Alternative Crops
• Mimic the herd effect, creating ecological succession • Graze once for every 10 inches of rain: 22 inches here, so two grzing passes annually • Don’t graze the same area two years in a row at the same season • Use many small pastures. In this case, 30-40 to encourage even grazing and no overgrazing • One to four days on a pasture, leave for 90-120 days. Rest for recovery • Leave lots of residual plants for decay, fertilization and water retention • Manage for biodiversity: warm and cool season plants.
Data Collection
Forage productivity and utilization has been measured in wach unit for natural forage and seeded forage. Livestock use has been recorded. Management (capital and operational) inputs have been recorded.
Forage will continue to be measured. Tree productivity will be measured. Soil samples will be taken to record microbiological activity and moisture holding capacity. `
Horticulture Growers' Short Course 47 Potatoes
2014 BC Potato Variety Trial: With a View from the Kitchen
Heather Meberg E.S.Cropconsult Ltd., Surrey, BC [email protected]
The BC Potato Variety Trial project demonstrates new varieties that may be of interest to our local growers. The potato variety trial project is generously funded through the Agri-Science Cluster for Horticulture 2, in partnership with Agriculture and Agri-Food Canada’s AgriInnovation Program, a Growing Forward 2 initiative, the Canadian Horticultural Council and the BC Potato and Vegetable Growers Association. The project was conducted by E.S. Cropconsult Ltd.
The 2014 trials were located in a ‘Kennebec’ potato field on 33A Avenue in West Delta. The field was managed by Ken Bates of Bates Brothers Farm. The plots were planted on June 6th, top-killed September 16th and harvested October 9th.
The plots were not irrigated this season and were protected with fungicides along with the rest of the field. The growing season was very hot and dry. There were 124 mm of rainfall between June 6th and September 16th with half of the rainfall occurring in June with a few timely rains in the main growing season.
In general, the BC potato growers are looking for new varieties with: • Better taste; • Better cooking quality; • Good looks; • Greater yield; • Improved storage longevity; • Pest tolerance; • Size and shape consistency; • New potato varieties that will work in our marketplace and our growing conditions. The ultimate goal is potatoes that farms can grow and sell.
The 2014 variety trial included 52 varieties in the replicated trial. Five standards, 11 numbered varieties and 36 new-to-BC varieties were included in the agronomic portion of this trial for evaluation under BC growing conditions. There were three replicated plots and a demonstration plot for each variety. A field day was held in late August with a turnout of over 125 growers and industry partners. Participants viewed harvested demonstration plots as well as the replicated plots.
Please see the table below for a summary of results from the agronomic portion of the trial.
Table. 2014 Potato Variety Trial Agronomic Results Summary Yield is the average of 20 hills in 3 plots of each variety converted to tons per acre. Uniformity of shape and size are on a scale of 0-5 with 5 being most desirable and 0 least desirable. Potatoes were grown for approximately 100 days (from planting to top kill).
Horticulture Growers' Short Course 48 Potatoes
Planted June 6 and harvested October 9. The field was not irrigated but received some timely rains.
Uniform Uniform Overall Purples t/ac Shape Size Appearance Comments Hot02-7001/Violet Queen 13 3 4 4 Purple Magic 14 4 4 3 Uniform Uniform Overall Reds t/ac Shape Size Appearance Comments Mazama 10 4 4 4 Very uniform – great taste AR 2014-07 12 4 4 3 Pale skin AR 2014-15 12 4 4 4 Dark and round Bordeaux 13 4 4 4 Low yield but looks good Norland 13 5 5 5 AR2013-09 13 4 4 4 CV99256-2 (AR2013-06) 14 4 4 4 Nice but has netting Alta Rose 16 4 4 4 Has netting Modoc 16 4 4 4 Bright round red Carolina 17 4 4 4 Barcelona 19 4 4 4 Nice but a little pale AR 2014-13 19 4 4 4 Netting and stems attached Uniform Uniform Overall Red/Yellows t/ac Shape Size Appearance Comments AR 2014-05 14 4 4 4 Variable skin colour Rosara 16 2 4 4 Spindly tubers Mozart 16 4 4 4 Variable skin colour Labella 21 4 4 4 Very nice Uniform Uniform Overall Russets t/ac Shape Size Appearance Comments Gold Rush 12 2 4 3 Oval shaped russet Russet Norkotah 14 4 4 4 Gem Russet 14 4 4 4 Ivory Russet 16 2 4 3 Tubers were knobby Alta Crown 16 2 4 3 Alta Cloud 16 3 4 4 Nice oval russet GemStar Russet 17 4 5 5 Good size, look great Uniform Uniform Overall Whites t/ac Shape Size Appearance Comments CV96044-3 12 4 4 4 Nice round white, skinning Gemson 13 4 4 4 Nice bright white Cascade 15 4 4 4 Buff skin, nice AR 2013-05 15 4 4 4 Flesh is very crisp Shepody 15 3 4 3 Sifra 16 4 4 4 Very nice, good uniformity Kennebec 17 4 4 4 Good oval shape Alta Strong 17 2 4 3 Good blocky white Imola 18 2 4 3 Very nice, smooth
Horticulture Growers' Short Course 49 Potatoes
Uniform Uniform Overall Yellows t/ac Shape Size Appearance Comments Bright smooth skin – fries Butterfly 12 4 4 4 well Citadel 13 5 5 5 Looks great Oriana 14 4 4 4 Nice potatoes AR 2014-08 15 4 4 4 AR2013-10 15 3 4 4 Sylvana 16 4 4 4 Dark lenticels Agata 16 3 4 4 Milva 16 2 4 3 Misshapen tubers Yukon 17 4 4 4 Montreal 17 3 4 4 Variable flesh colour Nicola 18 3 4 4 Krone 18 2 4 3 Variable shape Melody 18 4 4 4 Bright and round AR2013-07 18 3 4 4 Buff skin, a little soft rot Colomba 19 4 4 4 Musica 19 3 4 3 Laperla 19 4 4 4 Connect 20 4 4 4 Nice but dark lenticels
In a second component to the field trial, cooking assessments are performed on selected varieties in four teaching kitchens. The results of this component are still on-going. Preliminary results indicate that both ‘Capri’ and ‘AR2013-07’ performed better than the industry standard ‘Yukon Gold’ in the sensory analysis at all four kitchens. Whereas in the white (‘Norchip’) and red (‘Norland’) categories the industry standards remained in top place. Knowing whether a new variety performs well in the kitchen is critical in determining marketability.
Thank you to all of the BC potato growers and industry who help make this project a success, to our funding partners, seed growers who provide seed for the trial and to the chefs and their students who allow us to invade their kitchens.
For more information on the varieties in the trial please contact: Susan Smith - BCMAFF Field Vegetable Specialist: Phone: 1-888-221-7141 Heather Meberg, E.S.Cropconsult Ltd.: Phone: 604-841-0764
Horticulture Growers' Short Course 50 Floriculture
Pot Azaleas, Flanders' Pride: How Breeders, Growers and Researchers Join Efforts to Create a Success Story
Stefaan Werbrouck Ghent University, Belgium [email protected]
During two centuries, azalea breeders used the rhododendron gene pool to create fancy pot plants with double flowers, subtle color variations and extended flowering. In close interaction, researchers and growers refined production practices. Nowadays specialization, automation and flexible marketing allow growers of Flanders ‘Gent azalea’ to stay competitive.
1. Origin and breeding milestones
Around 1840, the Belgian pot azaleas originated from crosses between collected species from the Far East. This was principally R. simsii, but likewise R. mucronatum, R. indicum and R. scabrum, all belonging to the Tsutsusi subgenus, contributed to the gene pool (De Schepper et al. 2001; Scariot et al, 2007). Pot azaleas carry the scientific name R. simsii hybrids and constitute a group of small evergreen shrubs that have glossy dark green leaves and flourish abundantly.
Although they are mainly grown in the Belgian Ghent region, historically seen, the most successful cultivars were bred by Germans, followed by Belgians (Heursel, 1999). In Belgium the currently most important breeders are the private company Hortibreed and the Institute for Agricultural and Fisheries Research (ILVO) which harbors the breeding cooperative AZANOVA, supported by 21 nurserymen. During the breeding history of pot azalea, following several impressing landmarks can be recognized.
Double flowers – As in many other ornamentals, the double-flower trait appeared, a mutation that transformed stamens into petals and was rapidly introduced in the early cultivars. Double flowers last longer because self-pollination is avoided. Another homeotic mutation, which converted sepals to petals, was called hose-in-hose and can still be observed in a number of cultivars
Sport series – Pot azaleas are vegetatively propagated by cuttings and the most successful cultivars are cloned million fold. As a consequence, attentive growers could spot flower color sports in the forcing greenhouses. These are mainly sequential loss-of function mutations. In a clonal population with carmine flowers a sport with for instance red flowers is detected and propagated. This sport is supposed to give a new sport with pink flowers which in turn probably will yield a sport with white flower. The Belgian pot azaleas sport relatively easily, probably by the presence of instable transposons, a trait inherited from its main ancestor R. simsii (Heursel, 1999). To speed up the sporting process in promising new cultivars, breeders might use gamma irradiation treatment. The advantage of growing sport series is obvious. A large flower color range is available for the customer and the grower has the advantage that all plants from such a clonal group demand the same cultivation treatments. This allowed specialization and mass production.
Growing on own roots – The early cultivars had to be grafted because they grew less vigorous on their own roots. Nowadays grafting is too laborious (expensive) and is only practiced for growing big exhibition plants. Cuttings of modern selections have to root easily to make a change on the market.
Horticulture Growers' Short Course 51 Floriculture
Attractive colored candle stage – the customer is attracted by plants that show a colorful flower bud that promise a profuse flowering. The first cultivar with this appealing feature was ‘Friedhelm Scherrer’.
Extended flowering season and flowering time – whereas natural flower season of the ancient cultivars was around Christmas, current cultivars can flower naturally from August (very early cultivars) to May (very late cultivars). By means of extra cultural techniques, the flowering period can even be advanced or delayed. A historical breakthrough in this regard was the very early-flowering cultivar ‘Hellmut Vogel’ in 1967. Moreover, by continuous selection, the individual flowering of each flower was prolonged. In cultivars like ‘Christine Matton’ this can easily encompass 3 weeks.
New plant growth habit, flower shapes and colors – Azaleas normally grow globular: In the late eighties pyramidal growth was introduced by ILVO by introgression of a gene from R. noriakianum (Heursel, 1991). Hortinno crossed lanceolate leaved Satsuki azaleas to select ‘Kinku Saku’ a cv. with lanceolate leaves and long lasting spider type flowers. AZANOVA launched rose bud shaped pot azaleas. Flowers can range in color from purple over carmine red to red, pink and white. Although genes for yellow flowers are available in the rhododendron gene pool, attempts to obtain yellow pot azaleas have failed thus far.
Transgenic pot azalea – The first transgenic pot azalea with a commercially interesting trait was produced in 1999 by the author. The plants, which expressed a cell division inhibitor, grow compact and bloom profusely without pruning or the use of growth retardants. They are not on the market.
Horticulture Growers' Short Course 52 Floriculture
2. Production
The culture starts by rooting 3 to 5 cuttings directly into the final pot. At every pruning phase, not only the number of branches increases, but propagation material is produced as well. In summer, after a second pruning, the plants are transferred to outdoor container fields. During vegetative growth plenty of water is provided. By closed systems, the water is recycled as much as possible. To save manual labor, manual or robot pruning is alternated by chemical pinching agents such as methyl esters of C6-C12 fatty acids. Vegetative growth and flower initiation is controlled by plant growth regulators such as chlormequat and paclobutrazol. Also later, when flower buds are fully developed, a treatment with paclobutrazol prevents the outgrowth of axillary shoots by transforming them into multiple flower buds at the end of each branch. Price depends on plant diameter, which is often measured by image analysis and directs automated sorting. A cold period is necessary to break flower bud dormancy and to warrant blooming quality. Early cultivars require a shorter cold period then late cultivars. The plants are subsequently forced in heated greenhouses until they show colored buds. In the shops the inflorescence develops into an attractive ‘candle’ stage.
3. Marketing
In 2012, 30 million pot azaleas were produced by about 80 growers. About 80 % of the production is located around Ghent (EROV, 2012). They are mainly exported within Europe. Marketing is organized at different levels. VLAM, Flanders' Agricultural Marketing Board and the Flemish azalea growers association joined forces to protect ‘Ghent azalea’ as a European ‘Regional Product’. To obtain the protected geographical indication (PGI) ‘Ghent azalea’, pot azaleas have to be cultivated and forced in East Flanders (Belgium). When commercialized, the plant has to show 80% colored buds. The participating nurseries are registered and independently monitored and have to take part in flowering trials to warrant strict quality requirements.
On top of this, the plant breeders also control the chain from grower to consumer regarding their own cultivar releases. AZANOVA groups their new rose bud shaped azaleas under the brand Aiko®. Hortibreed launches their new cultivars under the brand Hortinno®. To avoid overproduction, they generally restrict the production to a limited number of growers. They apply internal quality control systems and consider sustainable production practices as an added value. They try to avoid neglect by inattentive retailers, which leads to wilted plants on the shop displays. Therefore, they even select and control the flower shops that are allowed to sell their plants. Careful website design completes this marketing strategy. The breeders cooperate to introduce their selections on other markets, such as Japan. Export of azaleas is often organized by export companies that have their own marketing approach. A number of individual growers don’t hesitate to launch their own labels. An example is the company Mario Naudts with ‘Queen of Flowers’, a strategy supported by his exclusive website, and even an own fashion/life style magazine. The legendary Ghent Floralies are usually held every 5 years and give a central role to the pot azalea. The azalea growers cherish this flower show tradition and display their most beautiful plants, giving their sector an extra international marketing boost.
4. Conclusion
The wildtype Rhododendron simsii plants that were imported almost two centuries ago, were slowly transformed into a group of fancy pot plants with double flowers, subtle color variations and extended flowering. Breeders keep on releasing cultivars that are adapted to consumer taste and modern growing practices that are based on specialization and automation. Quality monitoring and flexible marketing tools allow growers of Flanders azalea to stay competitive.
Horticulture Growers' Short Course 53 Floriculture
5. References
De Schepper, S., Leus, L., Mertens, M., Van Bockstaele, E., De Loose, M., Debergh, P., & Heursel, J. (2001). Flow cytometric analysis of ploidy in Rhododendron (subgenus Tsutsusi). HortScience, 36(1), 125-127.
Heursel J, Saverwyns A, Mertens M (1991) Azaleateelt. Min.van landbouw, 196 pp
Heursel J (1999) Azalea’s, Oorsprong, veredeling en cultivars. Lannoo/Terra,192 pp
Scariot, V., Handa, T., & De Riek, J. (2007). A contribution to the classification of evergreen azalea cultivars located in the Lake Maggiore area (Italy) by means of AFLP markers. Euphytica, 158(1-2), 47- 66.
Horticulture Growers' Short Course 54 Floriculture
How to Establish Natural Enemies in Ornamental Crops
Gerben Messelink Wageningen UR Greenhouse Horticulture, Bleiswijk, Netherlands [email protected]
Biological control of arthropod pests has been applied successfully in greenhouse crops for decades. The list of worldwide commercially available natural enemies goes up to 230 species and the 25 most sold species are mainly the ones used in greenhouse crops. Considering this relatively high number of available species, one might think that most greenhouse pests can be effectively controlled through the use of natural enemies. However, quite the contrary is true. Although commercialized NEs can keep damage caused by the main greenhouse pests, such as whiteflies, spider mites, aphids and thrips below threshold levels in most vegetable crops, this is not the case for many ornamental crops. Moreover, new pests continue to emerge through the invasion of exotic species as a consequence of global trade and global warming, or as a result of reduced and/or more selective use of pesticides. Here I summarize both the currently most problematic and persistent, as well as the newly emerging pest species in greenhouse ornamental crops in The Netherlands, which is probably very similar to the situation Canada. Furthermore, I mention some new methods to support the establishment of natural enemies for pest control in ornamentals.
The list of the 10 most important pest species in ornamental crops is presented in Table 1. It turns out that western flower thrips, Frankliniella occidentalis, is by far the most problematic pest, particularly in cut flowers. This is somehow remarkably because in most crops natural enemies such as predatory mites and predatory bugs have proven to be successful in the control of thrips. The main reasons for this lack of successful control are the poor establishment of these predators in cut flowers and the low thresholds for thrips densities due to their potential cosmetic damage.
Table 1. Top 10 most problematic pests in greenhouse ornamental crops in The Netherlands. Rank Common name Scientific name Relevant crops 1 western flower thrips Frankliniella occidentalis alstroemeria, amaryllis, carnation, chrysanthemum, roses, gerbera, potted plants 2 mealybugs Planococcus citri roses, potted plants pseudococcus longispinus Pseudococcus viburni 3 armoured scales Diapsis boisduvalii cymbidium, palms Aulacaspis rosae roses 4 whiteflies Trialeurodes vaporariorum gerbera, roses Bemisia tabaci Pointsettia 5 Echinothrips Echinothrips americanus gerbera, roses, potted plants (Anthurium, Spathiphyllum) 6 tarsonemid mites Steneotarsonemus laticeps Amaryllis Steneotarsonemus ananas bromeliacae Polyphagotarsonemus latus gerbera, cyclamen Tarsonemus violae 7 aphids several species potted plants, lilies, roses, chrysanthemum 8 Duponchelia Duponchelia fovealis gerbera, cyclamen, Euphorbia 9 Lyprauta Lyprauta chacoensis and Phalensopsis
Horticulture Growers' Short Course 55 Floriculture
Lyprauta cambria 10 spider mites Tetranychus urticae Aster, palms, Dendrobium orchids, Tetranychus cinnabarinus chrysanthemum Carnation The establishment of natural enemies and their population numbers can be enhanced by providing additional resources, such as alternative food, prey, hosts, oviposition sites or shelters. Some examples that have proven to be successful are: • Food spray with cysts of Artemia franciscana to support mirid predators (Macrolophus, Dicyphus); • Food sprays with pollen (e.g., Typha pollen, maize pollen) to support the predatory mite Amblyseius swirskii; • Mulch layers based on bran, yeast and fungi-feeding mites to support leaf-dwelling predatory mites (migration between soil and plant); • Banker plants with alternative hosts for aphid parasitoids (be aware of hyperparasitoids!); • Banker plants with pollen to support populations of Orius predatory bugs.
By conserving natural enemies and creating a “standing army”, the selection of new natural enemies may also shift from more specialist pest-adapted natural enemies to more generalist crop-adapted natural enemies. A new approach could be to select predatory mites that are more crop-adapted rather than pest specialised. An interesting group of mites for this approach are the Type IV predatory mites that also feed on the plant. This trait could result in a better establishment of predators on the plants in absence of prey or at low prey densities and is interesting to include in further studies with predatory mites, particularly for greenhouse ornamentals. A similar trend can possibly be expected from the group of generalist mirid predatory bugs. The Miridae is a large family of omnivorous bugs that feed both on plant material and animal food, but the degree of carnivory ranges from facultative opportunistic prey feeding to specialised prey feeding. Because of their plant-feeding behaviour and oviposition in plant tissue, mirids maintain a close relationship with certain host plants. The enormous variation within this family of predatory bugs provides the opportunity to select new species that are better adapted to certain crops, climates (e.g., lower temperatures) or pest communities.
References with more background information
Messelink, G. J., M. W. Sabelis, and A. Janssen. 2012. Generalist predators, food web complexities and biological pest control in greenhouse crops. Pages 191-214 in M. L. Larramendy and S. Soloneski, editors. Integrated pest management and pest control - current and future tactics. InTech, Rijeka.
Messelink, G. J. 2014. Persistent and emerging pests in greenhouse crops: Is there a need for new natural enemies? IOBC/wprs Bulletin 102:143-150.
Messelink, G. J., J. Bennison, O. Alomar, B. L. Ingegno, L. Tavella, L. Shipp, E. Palevsky, and F. L. Wäckers. 2014. Approaches to conserving natural enemy populations in greenhouse crops: current methods and future prospects. BioControl 59:377-393.
Horticulture Growers' Short Course 56 Floriculture
Western Flower Thrips: Is The Game Over?
Raymond Cloyd Kansas State University, Department of Entomology, Manhattan, KS [email protected]
Western flower thrips, Frankliniella occidentalis is the most destructive and economically important insect pest of greenhouse-grown horticultural crops. Western flower thrips is a major insect pest due to a number of factors including 1) broad host-plant range, 2) high female reproductive capacity, 3) rapid life cycle, 4) resistance to insecticides, 5) virus vector, 6) feeding habit, and 7) small size. Western flower thrips are a concern to greenhouse producers because they cause both direct and indirect damage to plants. Direct damage is associated with feeding using their piercing-sucking mouthparts, resulting in discoloration and deformation of flowers and leaves. Indirect damage is affiliated with adult western flower thrips vectoring viruses such as tomato spotted wilt and impatiens necrotic spot virus. Therefore, greenhouse producers have a low tolerance for the presence of western flower thrips populations.
The management of western flower thrips has undergone minimal changes since it became an insect pest in the 1980’s. Below are the main themes or areas of emphasis related to plant protection associated with managing western flower thrips: • Cultural and physical management practices have “generally” not changed. • There has been a reliance on insecticides with a perception regarding what is currently available and what products will be available in the future. • There are always issues related to resistance and the need to rotate insecticides with different modes of action. • Management of western flower thrips involves an integrated approach.
The integrated approach to managing western flower thrips relies on understanding the fundamentals of plant protection. This includes 1) scouting, 2) cultural practices, 3) sanitation, 4) physical barriers, 5) insecticides, and 6) biological. Scouting, for example, is critical in assessing the population dynamics of western flower thrips populations, which helps time insecticide applications accordingly. Removing weeds from within and around the perimeter of the greenhouse is important, as many weeds serve as reservoirs for western flower thrips populations as well as sources of the viruses that they can vector (e.g., impatiens necrotic spot virus). The installation of insect or micro-screening over openings such as vents or sidewalls prevents adult western flower thrips from migrating into the greenhouse. This is particularly effective if weeds are present on the outside of greenhouses, especially near openings.
Western flower thrips have a cryptic or thigmotaxtic behavior in which they prefer to reside in tight- enclosed buds. This behavior, in which individuals reside in enclosed, concealed locations on plants, may reduce direct exposure to contact insecticides. It is possible that spray applications may select for an increased cryptic behavior (avoidance factor). The key to dealing with western flower thrips populations when using insecticides is timing of application (when the most vulnerable life stages—nymphs and adults—are predominantly present), coverage of all plant parts, and frequency of applications. However, every time an insecticide is applied, this places selective pressure on western flower thrips populations, thus enhancing the prospect for resistance.
There are 153 documented cases of insecticide resistance associated with western flower thrips populations world-wide. These cases of resistance involve insecticides in at least seven chemical classes. In fact, certain western flower thrips populations may possess multiple resistance mechanisms or resistance may involve multiple genes (polygenic). There are four biological parameters that contribute to resistance in western flower thrips populations. These are 1) short generation time (2 to 3 weeks), 2) high
Horticulture Growers' Short Course 57 Floriculture
female reproductive rate (150 to 300 eggs), 3) wide host-plant range (>250 plant genera), and 4) haplo- diploid breeding system. This means that males only have one set of chromosomes (haploid), so resistance genes are directly exposed to selection by an insecticide treatment. This subsequently increases the potential for resistance developing. Therefore, the primary way to avoid resistance development is to rotate insecticides with different modes of action. The mode of action is how an insecticide affects the metabolic and physiological processes in an insect pest. However, the rotation of insecticides assumes that the frequency of individuals resistant to one insecticide will decrease during the application of another insecticide—with a different mode of action. Below are examples of rotation programs for use against western flower thrips. These are eight-week rotation programs, with each insecticide applied once per week for two weeks: • SpinosadChlorfenapyrAbamectinPyridalyl • PyridalylAbamectinChlorfenapyrSpinosad • NovaluronAcephatePyridalylSpinosad • MethiocarbAbamectinPyridalylChlorfenapyr • PyridalylBeauveria bassianaChlorfenapyrSpinosad
It is important to understand that the immigration of western flower thrips adults into greenhouses from nearby field or vegetable crops may be exposed to insecticides with similar modes of action. Therefore, it is important to inquiry on what insecticides have been applied to field or vegetable crops within the last two weeks, so that an insecticide with the same mode of action is not applied to western flower thrips populations in the greenhouse.
There are number of biological control agents that may be used to regulate western flower thrips populations in greenhouses. These include predatory mites (Neoseiulus cucumeris, Amblyseius swirskii, and Stratiolaelaps scimitus), predatory bugs (Orius spp.), and entomopathogenic fungi (Beauveria bassiana, Isaria fumosoroseus, and Metarhizium anisopliae). When using biological control agents, it is critical to make releases or initiate applications prior to the establishment of “high” western flower thrips populations. In fact, in regards to the use of entomopathogenic fungi, research at Kansas State University (Manhattan, KS USA) has shown that rotation programs that incorporate entomopathogenic fungi are just as effective in suppressing western flower thrips populations as standard rotation programs that only include insecticides.
What does the future hold? Well, below are four points: • Due to the costs and regulations associated with registering new insecticides, very few new active ingredients will be introduced into the marketplace specifically for western flower thrips. • Greenhouse producers must implement a combination of plant protection strategies so as to alleviate problems with western flower thrips. • Due to issues associated with insecticide resistance, there will likely be an increase in the use of biological control against western flower thrips. • The global movement of plant material may possibly exacerbate problems with western flower thrips.
For more information on managing western flower thrips, consult the following extension publication and article:
Cloyd, R. A. July 2010. Western flower thrips management on greenhouse-grown crops. 8 pages (http://www.kres.ksu.edu/library/entml2/mf2922.pdf) Cloyd, R. A. 2009. Western flower thrips (Frankliniella occidentalis) management on ornamental crops grown in greenhouses: Have we reached an impasse? Pest Technology 3(1): 1-9.
Horticulture Growers' Short Course 58 Floriculture
What Is the Real Story Behind Declining Bee Health
Elizabeth Elle Dept. of Biological Sciences, Simon Fraser University, Burnaby, BC [email protected]
Pollinators are in the news a lot lately because of ongoing declines in managed honey bee populations, and increasing acknowledgement that wild bees are also in decline. Most wild bee data are for bumble bees, but when evidence is available it also seems to apply to other wild bees. Note that we have about 450 species of bee in B.C.
The general public is aware of pollinator declines, and also aware that pesticides like neonicotinoids may be contributing. There are new labelling requirements for some “big box” stores and some municipal groups, like the Vancouver Park Board, are banning neonicotinoid-treated bedding plants from public spaces. All of this suggests it is important for the floriculture industry to understand why pollinators are in decline. The main reasons (for both managed honey bees and for wild bees) are diseases, exposure to pesticides, and habitat loss.
Diseases
Mites are one of the biggest problems for honey bees, and they became resistant to the most commonly used chemical controls in the early 2000—and honey bee declines followed soon after. Honey bees also suffer from a large number of viral, fungal, and bacterial diseases. Wild bees likewise have some emerging diseases and there is evidence that there is disease transfer from managed honey bees to wild bumble bees.
Pesticides
Chemical treatments are important for pest control but they can have negative effects on beneficial insects like bees. These impacts are sometimes acute and cause bee death, but the more concerning impacts are those that are chronic. Obvious bee death does not occur, but other impacts lead to reduction in population growth or even population decline. For example, neonicotinoids appear to have especially concerning effects on the ability of honey bees and bumble bees to learn—and “learning” is essential for bees to find flowers (pollen and nectar = food) and return to the hive or nest to feed offspring. When foraging rates or foraging efficiency decline, the population can decline. There are many plants where the length of residual activity of neonics hasn’t been investigated, but it is fair to assume that soil drench applications will retain activity throughout the bloom period of many, if not most, annuals. Other recent research shows that spray adjuvants and fungicides can also affect bee learning, and so have the potential to affect bee populations. Following label directions about the timing of treatments is essential.
Habitat Loss
The loss of food from flowers, and the loss of nesting sites, are the main cause of wild bee population declines. Gardens can provide both food and nest sites to wild bees, and so my research group always encourages people to plant a garden. We have info on bees and on bee-friendly garden plants on our web site: http://www.sfu.ca/biology/faculty/elle/Bee_info.html
In honey bees, diet has been shown to be important for health and activity levels. Unfortunately when they eat a single-pollen diet (as on crop monocultures) honey bee colonies grow less fast and the
Horticulture Growers' Short Course 59 Floriculture
probability of surviving when infected with disease is lower. These results likely apply to wild bees as well, but they haven’t been studied in this context.
The bottom line is that pesticides are just one of several reasons why pollinators are in trouble, but they are a part of the story that the floriculture industry can do something about. Given that plants are sometimes marketed as ‘pollinator friendly’ or for butterflies, bees, or hummingbirds, considering pesticide treatments that are more pollinator friendly is a good way to go.
Horticulture Growers' Short Course 60 Floriculture
New Tools and Advances to Battle the Mildews
Mary Hausbeck Department of Plant, Soil & Microbial Sciences, Michigan State University [email protected]
Downy Mildews
Downy mildew may occur sporadically on some crops, but can be a predictable pest on others. There are many different pathogens that are responsible for the downy mildew diseases and most are restricted to only one or a few plant types. For instance, the downy mildew pathogen that infects rose is specialized and does not cause disease on other ornamentals. If you’ve been struggling with downy mildew on coleus, snapdragon, or impatiens, for example, the rose downy mildew pathogen is not the culprit!
Downy mildew can occur on all aboveground plant parts, blighting the leaves and stems. Sometimes the first symptoms of downy mildew are confused with a nutrient deficiency or spray injury. On the leaves, spots may be purplish or brown and appear square since they may be limited by the larger veins. Downy mildew that infects some plants, such as roses, doesn’t always produce a fuzzy mat on the underside of the leaf that is noticeable without magnification. On other species, such as impatiens and coleus, sporulation may be observed easily on the underside of an infected leaf. Often infected leaves drop from the plant and when the infection is severe enough, may leave the plant nearly devoid of foliage. Once the diseased leaves start dropping, the downy mildew is advanced and stopping it becomes very difficult.
Downy mildew is very responsive to weather cues. When the weather favors development of the downy mildew, symptoms can explode almost overnight. Wet weather, high relative humidity, and overcast conditions are triggers to the downy mildew disease. In outdoor growing facilities, fog can provide nearly the perfect weather for an outbreak. During wet weather, a fine weft of fungal threads can coat the underside of the leaf. This is where the downy mildew pathogen reproduces via a spore type called a sporangium. Sporangia develop and ripen during the night as long as there is darkness and at least 6 hours of continuous moisture. When the environment begins to dry in the early to mid-morning hours, the air currents pluck the sporangia from their spore stalks and carry them to nearby healthy foliage.
Since the downy mildew pathogen can lay quiet in tissue without noticeable blighting, it is possible to receive plants that appear healthy only to have downy mildew symptoms develop later. It is also possible for the downy mildew pathogen to persist in a greenhouse or production facility, causing disease from one season to the next. A specialized spore (oospore) can remain dormant in infected plant debris and soil, surviving harsh weather conditions and allowing the downy mildew pathogen to survive between crops.
One of the most common mistakes with downy mildew is confusing it with the similarly named pathogen, powdery mildew. Powdery mildew infections will produce white talcum powder like sporulation, usually on the upper side of the leaf. Control methods for powdery mildew will unfortunately not control downy mildew. So it is important to properly diagnose which pathogen you are dealing with.
Impatiens Downy Mildew
Downy mildew on impatiens is a relatively new disease problem for greenhouse growers in the United States. It was noted in 2004 in Michigan greenhouse and it was observed widely in Michigan landscapes in summer/fall 2012. The downy mildew pathogen is Plasmopara obducens and infects bedding impatiens, double impatiens, and balsam; however, New Guinea impatiens, other flowering bedding plants, and vegetables are not susceptible. Bedding impatiens are a favorite for use in shady areas where
Horticulture Growers' Short Course 61 Floriculture
they are planted in masses for bright color in the landscape. Double impatiens are used in hanging pots, planters, and decorative pouches.
Diseased impatiens may appear to be a bit off color with a white mildew coating the underside of the leaves. As the infection continues, the leaves turn yellow and may fall off the plant leaving only the stems behind. The white mildew coating on the undersides of the leaves are sporangia that move around the environment via air currents. When that spore settles out of the air onto impatiens leaves, a new infection results. Especially long lasting oospores may form in the stems and leaves of infected impatiens. These long lasting oospores are not readily visible without the aid of a microscope and were found in Michigan samples gathered from the landscape. If the impatiens plants with this long lasting oospore are not promptly removed from the greenhouse or garden and disposed of, the garden soil may become contaminated with the downy mildew pathogen. Once the garden soil is contaminated with these long lasting downy mildew oospores, it may become difficult to successfully grow impatiens in the same location in another year.
Once the plant is infected, there are no fungicides that can “cure” the plant. Many other crops also have their own specialized downy mildew and we’ve learned that as a group, the downy mildews are quite adept at changing on a genetic level so that they can overcome fungicides. Therefore, a fungicide program must be well thought out and utilize multiple fungicides that have proven activity against downy mildew. Using fungicides preventively, prior to the infection of downy mildew, is also helpful in delaying resistance developing in the downy mildew pathogen. Initiating a fungicide program in the midst of a raging downy mildew epidemic increases the risk of the downy mildew pathogen developing resistance. Alternating fungicides and tank mixing two fungicides with different ways of attacking the downy mildew can also be an important strategy in managing the disease and helping to prevent the development of fungicide resistance.
Greenhouse growers and professional landscapers have some fungicide choices available to them. However, this pathogen is devastating if the most effective products are not used in an Greenhouse: Impatiens Downy Mildew 100 intensive application program. Most of the Bars with a letter in common downy mildew fungicides are newer materials 80 b are not signficantly different and growers may not be readily familiar with 60 them. Adorn (fluopicolide), Stature (dimethomorph), Segway (cyazofamid), 40 Micora (mandipropamid) and Fenstop 20 a a a aa a a (fenamidone) are examples of some of the 0 Sporulatingleaf area (%) Untreated Adorn Plentrix Subdue Micora Micora Disarm Heritage newer fungicides that can be used for downy uninoculated SC 50WG MAXX EC SL SL O SC 50WG mildew. Michigan State University research 2 fl oz 1.3 fl oz 1 fl oz 4 fl oz 8 fl oz 4 fl oz 4 oz drench drench drench foliar foliar foliar + Capsil conducted to date indicates that some spray spray spray 4 fl oz foliar materials are better when applied as a drench spray compared to application as a foliar spray (see graph, right). A broad-spectrum fungicide such as Protect DF/Dithane (mancozeb) can be used as a tank mix partner with other more specific downy mildew fungicides that have some systemic activity. A Subdue (mefenoxam) drench, which is often used for Pythium can also provide downy mildew protection. Heritage/Plentrix (azoxystrobin) and Insignia (pyraclostrobin) sprays can be helpful against downy mildew and Alternaria leaf blight. Phosphorus acid-based products (Jetphiter) may also prove to be helpful. In general, adjuvants are not needed and in our experience with other downy mildew pathogens, do not enhance downy mildew control. However, adjuvants may help reduce the appearance of fungicide residue.
Horticulture Growers' Short Course 62 Floriculture
Coleus Downy Mildew
Downy mildew was first observed on coleus in New York and Louisiana in 2005 and by 2006 it was found throughout most of the United States. Symptoms include leaves dropping off plants, brown blotches on leaves (Fig. 1A), and stunted seedlings. Both seed and vegetatively-propagated cultivars are susceptible. The brown or blighted areas on diseased foliage have an irregular shape and can cause the leaf to twist and drop. Sometimes these spots look square or angular and are bordered by large leaf veins. The fungus reproduces via specialized spores called sporangia that may sometimes be seen on the underside of the coleus leaves. In some instances, these sporangia may be few in number and very difficult to see without the help of a microscope. Other times, the sporangia are produced in high numbers and form a fine carpet of grayish fuzz on the underside of the leaf that is obvious to the naked eye (Fig. 1B). These lemon- shaped sporangia are produced on a spore stalk (Fig. 1C). It is A best to look for these sporangia when the environment is humid and damp.
The fungal-like organism that causes downy mildew on coleus is tricky and elusive. Sometimes the disease is obvious and other times it may lie quietly in the plant tissue until the conditions are just right for the disease to develop. For this reason, it is important that all coleus plants that may be left between production seasons be destroyed. Resist the urge to carryover any leftover plants of B your favorite cultivars. Also, it is not advisable to use coleus in outdoor plantings that border production greenhouses. It is possible that coleus seedlings and/or cuttings may arrive at your greenhouse and appear healthy, only to develop downy mildew later. Since this disease is relatively new to the United States, research has been needed to determine whether there is a difference among cultivars and which fungicides work best. Knowing these fundamentals will go a long way in producing a crop that looks healthy and stays healthy in the landscape. C
Although it seems that all coleus cultivars may be affected by downy mildew, the amount of blighting and leaf dropping that results may vary among the cultivars. Coleus cultivars may also differ in how many sporangia are produced on coleus leaves. This is an important characteristic because the sporangia are responsible for spread of the downy mildew. Wind currents or splashing water dislodge sporangia and make them available to infect nearby healthy plants. In a recent Michigan State University study, 15 coleus cultivars were compared for leaf blighting and Fig. 1. Blighting on coleus variety sporangia production. All of the varieties, with the exception of ‘Color Pride’ (A), underside of ‘Dragon Black,’ were supplied from the USDA-ARS North ‘Dragon Black’ showing Central Regional Plant Introduction Station for testing. Plants sporulations (B), downy mildew were sprayed with the downy mildew pathogen and kept together sporangia on spore stalks (C). in a humid research greenhouse. All cultivars tested developed disease symptoms although some cultivars became more diseased than others. Examples of the coleus cultivars that held up well in our study included: Freckles, Beauty, Russet, Harlequin, and Pegasus. Although these cultivars showed downy mildew symptoms, the disease was relatively mild. High susceptibility to downy mildew was observed on cultivars Duke Yellow, White Gem, and Cristata (Table 1). The popular variety Dragon Black was again observed to be very susceptible and if you are
Horticulture Growers' Short Course 63 Floriculture
determined to grow this cultivar, preventive fungicide applications might be necessary. In other studies, cultivars Volcano, Wizard Rose, Wizard Golden, Wizard Coral Sunrise, and Versa Watermelon were all determined to be highly susceptible as well. Most cultivars that had the highest percentage of sporulating foliage also had the highest concentration of sporulation on each leaf. Unfortunately at this time we cannot say for sure that we know of a cultivar that is completely resistant to this new pathogen; however, some varieties appear to be less affected. Table 1 is a listing of the general susceptibility levels of some coleus cultivars we have tested.
Table 1. Susceptibility of coleus cultivars to downy mildew. Coleus cultivar Susceptibility level* Coleus cultivar Susceptibility level* Beauty Low Duke Yellow Medium Dark Chocolate Low Giant Rustic Red Medium Etna Low Versa Burgundy Medium Freckles Low Versa Crimson Medium Giant Palisandra Low Versa Green Medium Glory of Luxemborg Low Versa Rose Medium Harlequin Low White Gem Medium Pegasus Low Wizard Pink Medium Pineapple Beauty Low Wizard Mosaic Medium–High Russet Low Dragon Black High Tapestry Low Versa Watermelon High Versa Lime Low Volcano High Beckwith’s Gem Low–Medium Wizard Coral Sunrise High Chocolate Mint Medium Wizard Golden High Cristata Medium Wizard Rose High *Please note that these results may be from only a single trial and that you may see variances in susceptibility in these cultivars in your greenhouse.
12 Adorn applied as a drench, all perplant 10 d other treatments as a foliar spray, treatments applied once. 8 Bars with a letter in common 6 are not significantly different. SNK; P=0.05 c 4 bc bc 2 a ab a a a a ab
sp. Peronospora a a a a a 0 Avg. # of leaves sporulating #of leaves Avg. with
Regalia SC 1%Regalia SC 0.5% SP2015 50DF 12 oz Adorn 4SC 2 fl Adornoz 4SC 1 fl oz UntreatedBAS inoculated 651FBAS F 11651F FenStopfl oz 13.4Stature fl SC oz 14 SC fl oz 6.12 fl oz Heritage 40WG 4 oz Disarm Disarm480SC 4480SC fl oz 2 fl oz SubdueNOA MAXX 44610 EC 1250SC fl oz 4 fl ozNOA 44610 250SC 8 fl oz
Downy Mildew Control and Recommendations
With the downy mildew pathogen, sometimes cultural control methods are not enough and fungicides are needed for protection. Fungicide studies have been conducted at Michigan State University with products that are currently registered and others that are not yet registered. One study included newly registered products such as Adorn and Disarm compared with FenStop, Heritage, Stature, and Subdue MAXX (see graph testing fungicides for coleus downy mildew control, above). Although all treatments limited infection compared to the untreated control, differences were observed between the products tested.
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FenStop SC, Stature SC, and Subdue MAXX EC were the only treatments that completely prevented infection in this trial. Although Adorn SC limited infection compared to the untreated control, the numbers of infected leaves were still at levels unacceptable to growers.
Downy Mildew Fungicide ‘A’ Team Downy Mildew Fungicide ‘B’ Team Adorn fluopicolide Compass O trifloxystrobin Alude/Jetphiter phosphorous acid salts Disarm ) fluoxastrobin FenStop fenamidone Heritage azoxystrobin Micora mandipropamid Insignia pyraclostrobin Orvego ametoctradin + dimethomorph Pageant pyraclostrobin + boscalid Segway cyazofamid Protect DF mancozeb Stature dimethomorph Subdue MAXX mefenoxam
Use a combination of techniques to prevent and control downy mildew. Keep the environment dry, practice good sanitation, and use effective fungicides.
• Purchase high quality plant material from reputable sources. • Early detection helps time fungicide applications. • Look for necrotic spotting on the leaves as early symptoms of downy mildew. • Keep air moving whenever possible so that relative humidity is kept low. In outdoor production facilities, arrange plants in rows that take advantage of the prevailing winds to dry the foliage. • Choose effective fungicides and reapply frequently, especially when the weather favors the disease. • In some instances, a 5- to 7-day fungicide spray schedule may be needed. Alternate fungicides so that label restrictions regarding the application interval are not violated. • Help delay resistance to fungicides developing by alternating products with each application. • Fungicides must be applied so that the plant is thoroughly covered with the spray. Even though some products offer systemic movement within the plant, the entire plant must be covered with the fungicide spray for the needed protection. • All plants with downy mildew should be disposed of or destroyed at a location far from the production facility. Cull piles must be avoided because this would be a likely place for the downy mildew to survive and cause problems for new crops.
Powdery Mildews
The white talcum-like colonies of powdery mildew can start small but can rapidly blight the leaves, stems, and flowers of susceptible crops. Some powdery mildews can be specific to one type of plant while other powdery mildews, such as Erysiphe cichoracearum, can infect many different annual and perennial flowers and vegetables. The abundant conidia (spores) give a white, powdery or fluffy appearance. There are times when identifying the disease Powdery Mildew on Aster 'Henry I' 10 can be difficult as infection Bars with a letter in common c are not significantly different sometimes can only cause 8 yellowing and withering of b leaves and stunted plant 6 growth. High relative humidity can prompt 4 epidemics. Some plant species such as gerbera daisy, 2 a a a calibrachoa, asters, and a Health (1=healthy, 10=dead) (1=healthy, Health 0 Untreated Terraguard Pageant Palladium Tourney Gantec GREEN SC 8 fl oz 8WG 12 oz WDG 6 oz 50WDG 4 oz EC 8 fl oz 7-day 7-day 7-day 14-day 5-day Horticulture Growers' Short Course 65 Floriculture
verbena are very susceptible and should be sprayed more frequently with the most effective fungicides. Other plant species may not need frequent applications but should be scouted regularly for signs of the disease. It should be noted that certain cultivars of a plant species may be more susceptible than others.
Growing susceptible crops can be a challenge, and fungicides (see graph, previous page) have typically played a key role. Powdery mildews are tricky and have been known to genetically adapt to overcome some of the most effective fungicides. You may want to start out with the most effective products, such as Eagle, Terraguard and Tourney if you are growing an especially susceptible crop. Currently there are several excellent products available (A-/B Team) to rotate with your best fungicides in a comprehensive spray program.
Powdery Mildew ‘A’ Team Powdery Mildew ‘A-/B’ Team Eagle myclobutanil Compass O WDG trifloxystrobin Terraguard SC triflumizole Heritage WDG azoxystrobin Tourney metconazole Insignia WG pyraclostrobin Pageant WG pyraclostrobin + boscalid Palladium WDG fludioxonil + cyprodinil Strike WDG triadimefon Zyban WSP t-methyl + mancozeb
Acknowledgements
This material is based upon work supported by Specific Cooperative Agreement 58-1907-0-096 with USDA ARS under the Floriculture and Nursery Research Initiative and by the American Floral Endowment.
Horticulture Growers' Short Course 66 Field Vegetables
Yellow Nutsedge: A Beast of a Weed
Tim Miller WSU Mount Vernon – NWREC, Mt. Vernon, WA [email protected]
Yellow nutsedge (Cyperus esculentus) is a perennial member of the plant family Cyperaceae, the sedge family. Yellow nutsedge leaves are pale green and pointed, three-ranked, and V-shaped in cross section. Stems are triangular and solid (pith-filled), and usually emerge after soils warm in late May to early June. Yellow nutsedge is ranked among the worst weeds in the world, and is now found in Africa, Australia, Asia, Europe, and South and North America. It is found in most southern tier provinces in Canada and throughout the US, except for Montana and Wyoming.
Horticulture Growers' Short Course 67 Field Vegetables
Yellow nutsedge is not without positive attributes. In Africa, Asia, and Europe yellow nutsedge is grown for its edible tubers. Tubers have a nutty flavor and are eaten raw, roasted, ground into flour, or made into a cold drink (Chufi). In 1941, 7,000 acres of yellow nutsedge were planted for hog pasture in Florida.
Yellow nutsedge is adapted to warm, humid conditions. Growth is favored by high light intensity. Tubers tolerate drought, and certain biotypes can handle cool climates such as what is found in British Columbia. In North America, yellow nutsedge is most troublesome in tropical/subtropical climates, but is also very bad in the southern US (California to Florida) and in parts of the Midwest. Basal bulbs (tips of rhizomes) sprout during the growing season, increasing the infestation. Basal bulb and rhizome growth is stimulated by high nitrogen and the long days of late spring and early summer. Conversely, tuber initiation and growth is stimulated by short days. Tuber formation begins 4 to 6 weeks after shoot emergence, and a single yellow nutsedge plant is capable of producing 7,000 tubers in a single year.
Most tubers germinate during the year after they are produced, but can survive 3 or more years in soil. Tubers are the primary survival organ and have a dormancy period associated with them. They have been shown to survive temperatures to 20°F and to produce new shoots which can emerge from a depth of 24 inches or more. Tubers can sprout numerous times before their energy reserves are depleted. Factors affecting the breaking of tuber dormancy include tillage, cool winter temperatures, high soil moisture, and placement near the soil surface. Deep tubers tend to stay dormant, where their winter survival is improved.
Yellow nutsedge tuber production by depth was investigated in a trial conducted in Ontario, Oregon (Corey Ransom, then with OSU) (Figure 1). Most tubers were initiated in July or later, and at a depth of 2 to 4 inches. By early August, an estimated 16 million yellow nutsedge tubers per acre were produced at that depth. Slightly fewer tubers were produced in the top 2 inches of soil, or from 4 to 6 inches deep (about 8 million/acre). Importantly, about 2 million tubers were produced per acre at depths 6 to 8 inches, and fewer than 1 million tubers/acre were produced at the 8- to 10-inch depth. While this is obviously a large number, it does display that this weed has limits to its tuber production, and that tuber production is reduced below about 6 inches.
Horticulture Growers' Short Course 68 Field Vegetables
Figure 2. Yellow nutsedge tuber production.
In a second trial (again by Ransom, OSU), packets of 10 yellow nutsedge tubers were planted at different depths up to two feet (Figure 2). Tuber packets were buried May 1, and then excised July 7, and the number of shoots and tubers produced during those two months were counted. The tubers producing the fewest shoots were at 18 or 24 inches, averaging 6.6 or 0.6 shoots/tuber, respectively. New tuber production was reduced if tubers were buried at 14 inches or deeper, with tuber number reduced more at deeper burial depths. This is an indication that deep burial of yellow nutsedge tubers may offer a strategy for controlling this species.
Figure 3. Yellow nutsedge shoot and tuber production from buried tubers.
Horticulture Growers' Short Course 69 Field Vegetables
The most important strategy for controlling yellow nutsedge is to not get the weed in the first place. Cleaning equipment is of paramount importance so as not to move tubers from one field to the next. Infested fields should be harvested last, when possible. Tillage may simply spread tubers through the field, so care should be taken when cultivating or plowing through dense patches. Deep burial can delay or prevent shoot emergence from tubers. Cultivation reduces early growth and allows the crop to better compete with the weeds. It is usually advisable to rotate crops to forages and small grains to increase competition with yellow nutsedge plants, reducing their productivity and their ability to produce new tubers.
There are two biological control agents for yellow nutsedge control in the US, including a moth (Bactrus veruntana) which has reduced yellow nutsedge growth in greenhouse trials, and a rust (Puccinia canaliculata) which has achieved 40 to 70 percent control of yellow nutsedge in some US trials. The effectiveness of these organisms appears to be linked to particular yellow nutsedge biotypes found mainly in the southeastern US, however, so the will be of only limited usefulness (if any) in other locations.
There are also chemical strategies (herbicides) that are registered for use in several crops. In potato, herbicides with activity on yellow nutsedge include Chateau, Dual Magnum, Eptam, Matrix (= Prism), Outlook, or Spartan. In silage corn, Callisto, Dual II Magnum, Eradicane, Lasso, Outlook, Permit, Sutan, or Harness/Surpass/Topnotch all show ability to suppress yellow nutsedge emergence and growth. In cucumbers, pumpkins, and squash, Sandea has good postemergence activity on the weed. There are no specific herbicides recommend for yellow nutsedge suppression in small grains, although sulfonylurea herbicides (such as Harmony Extra) will provide some level of yellow nutsedge control. Other herbicides with activity on this species include Nortron and Ro-Neet. Soil fumigants probably provide the greatest suppression of yellow nutsedge. Prior to cropping, metam or Telone C17 provide good control of this species. In field headlands or other sacrifice areas can be treated with Casoron, glyphosate, paraquat, Rely, and Sedgehammer for suppression of yellow nutsedge.
When mixing tillage with herbicides, treat yellow nutsedge foliage prior to tillage and repeat as necessary. With all these treatments, be aware of the potential for soil residuals to injure rotational crops.
Horticulture Growers' Short Course 70 Field Vegetables
Rots and Blights of Vegetables
Mary Hausbeck Department of Plant, Soil & Microbial Sciences, Michigan State University [email protected]
Cucumber Downy Mildew
Michigan cucumber and pickle growers have battled downy mildew (DM), incited by the water mold, Pseudoperonospora cubensis, since 2005. Resistant cultivars are not currently available and fungicides have been the only effective means of controlling this disease. This downy mildew pathogen is resistant to commonly used fungicides including Ridomil Gold-based products and the strobilurin fungicides (i.e. Cabrio, Quadris, and Flint). Results from our research have identified a limited number of fungicides that are effective, but they must be applied every 5-7 days to control downy mildew on cucumbers when weather favors disease (see Table 1).
Table 1. Fungicide recommendations for downy mildew on cucumber. Products* • **Previcur Flex 6SC (2 day PHI) • **Ranman 3.6SC (0 day PHI) • Gavel 75WG (5 day PHI) • Presidio 4FL (2 day PHI) • Tanos 50WG (3 day PHI) • Zampro 4.4C (0 day PHI) Alternate products and mix each with either: • Dithane (mancozeb) 3 lb or • Bravo (chlorothalonil) 1.5 pt *Before downy mildew is confirmed in the area, products should be applied at 7-day intervals, and at 5-day intervals after disease is confirmed. Use of the highest labeled rate of products is recommended. **These fungicides are especially effective under heavy disease pressure.
Cucumber Downy Mildew Fungicide Research
The Hausbeck lab has been working to ensure that pickle growers will continue to have the most effective fungicide products available. Through our research, the pickling cucumber growers and allied industries will know in advance whether previously effective strategies have remained durable or if alternative products/strategies are needed. In 2013, we tested new and unregistered fungicides for efficacy at low and high rates when applied alone or in a rotational program with other downy mildew fungicides; Table 2 lists the fungicides that were included in our research effort. FRAC codes are used to determine the mode of action that the active ingredient has on the pathogen.
Table 2. List of products tested for downy mildew control on cucumber. Product Active ingredient FRAC code Labeled Bravo WeatherStik 6SC chlorothalonil M5 yes Gavel 75DF mancozeb/zoxamide M3/22 yes Manzate Pro-Stick 75WG mancozeb M3 yes Presidio 4SC fluopicolide 43 yes Previcur Flex 6EC propamocarb 28 yes Ranman 3.3SC cyazofamid 21 yes Tanos 50DF famoxadone/cymoxanil 11/27 yes Zampro 4.4SC ametoctradin/dimethomorph 45/40 yes DPX-QGU42 OD 0.83SC experimental -- no V-10208 4SC experimental -- no
Horticulture Growers' Short Course 71 Field Vegetables
Once natural infection by downy mildew was confirmed in Michigan in late July, fungicide field trials were planted at the Southwest Michigan Research and Extension Center, Berrien County. Trials were arranged in a randomized complete block design with four replicates. Sprays were initiated at first true leaf and fungicide treatments were applied by broadcast foliar sprays directed to the foliage.
Single Product Fungicide Summary
This was a 17-treatment trial on ‘Vlaspik’ that included products applied alone at both a low and high rate (Fig. 1). The untreated control plots showed a foliar DM incidence of nearly 75%, whereas a new experimental fungicide (DPX-QGU42) completely prevented the disease. Overall, the weather in the Berrien County area was drier than other areas of the state and irrigation was needed.
80 e SWMREC 60
40
cd d 20 a-d b-d b-d a-d a-d Foliarinfection (%) a-d a-d ab a-d a-d a a ab a-c 0
s 0.5 lb Untreated Gavel 2 lb o Tan Ranman 0.17 ptRanmanV-10208 0.13 pt 0.63 pt V-10208 0.5 pt Zampro 0.88 ptPresidioPresidio 0.19 pt 0.25 pt Previcur Flex 1.2 pt DPX QGU42DPX QGU42 OD 0.04 OD pt 0.02 pt ManzateBravo Pro-Stick WeatherStik 2 Bravolb 3 WeatherStik ptManzate Pro-Stick 2 pt 3 lb Fig. 1. Registered and experimental fungicides tested for control of cucumber downy mildew. a Zampro* -alt- Previcur Flex* -alt- Ranman* a SWMREC Foliar Infection a Zampro* -alt- Tanos* -alt- Gavel a 'Arabian' a 'Vlaspik' Ranman* -alt- Tanos* -alt- Gavel a Rates (applied at 5-7 day intervals) Gavel 2 lb Ranman 2.7 fl oz a Presidio* -alt- Tanos* -alt- Gavel Presidio 4 fl oz Tanos 8 oz a Previcur Flex 1.2 pt Zampro 14 fl oz a *tankmixed with Bravo Presidio* -alt- Tanos* -alt- Ranman* a WeatherStik 2 pt a Presidio* -alt- Gavel -alt- Ranman* a a Presidio* -alt- Previcur Flex* -alt- Zampro* a a Presidio* -alt- Previcur Flex* -alt- Ranman* a
Untreated b b
0 10 20 30 40 50 60 Foliar infection (%) Fig. 2. Evaluation of cultivars and an alternating fungicide program for cucumber downy mildew.
Horticulture Growers' Short Course 72 Field Vegetables
Fungicide Program Across Two Cultivars Summary
Another trial was established in Berrien County where ‘Vlaspik’ and ‘Arabian’ cucumbers were treated with combinations/alternations of fungicides for DM control (see Fig. 2). Results from this plot answers some of the questions that growers often ask, including which fungicide program is preferred and/or which cultivar should I grow? In this trial (Fig. 2), DM in the untreated control plot was at about 60% for ‘Vlaspik’ and 35% for ‘Arabian.’ All fungicide treatment programs effectively limited DM compared to the untreated control. Please note that each DM fungicide was tankmixed with Bravo WeatherStik according to recommendations. The fungicide programs that included Presidio limited DM to less than 8%. All other fungicide treatments showed some level of DM with all treatments keeping disease to less than 11%.
Phytophthora Blight
Phytophthora capsici causes a rot or blight of the roots, crowns, stems, leaves, and/or fruits of summer squash, zucchini, hard squash, melons, and pumpkins. Plants may appear wilted initially and recover in the evenings but eventually will die. Also, following a rainstorm or overhead irrigation, soil containing the pathogen can splash onto the plant’s petioles causing a blighting near or just above the plant’s crown. Sometimes, the infected plant surfaces can be coated with white Phytophthora spores that can look similar to powdered sugar. It can be especially easy to find the powdered sugar symptoms on the infected fruit. Once the fruit become infected with Phytophthora, it becomes compromised and can become infected by other pathogens that may be secondary such as Pythium. When this happens, there will be a fluffy white appearance to the fruit that will grow over the white powdered sugar symptom that occurred first, making it hard to tell which pathogen is really at fault. Eventually the infected fruit will rot, but the pathogen structures that developed inside the diseased fruit will remain viable and serve to further infest the field soil causing increased problems in future years. It is possible to harvest fruits that look healthy with symptoms of Phytophthora rot appearing days later while the crop is in transit or on grocers’ shelves. A good way to avoid Phytophthora in a field is to take preventive measures before there is an outbreak (Table 3). If there is a history of Phytophthora in a field, do not plant susceptible crops.
Water management is an important component of managing Phytophthora. Hard squash, pumpkin, and other types of vine crops can be planted into raised beds which allow for excess water to move away from the susceptible root and crown area. This strategy has proven to be very helpful for pepper production but becomes more challenging to produce vine crops in this manner. Choosing cultivars with more of a bush- like habit versus a trailing vine habit may be helpful for use in conjunction with the raised plant bed system. Because the disease can spread through water, it is essential that fields are well-drained and that low-lying areas of the field are left unplanted. Overhead irrigation should be sparse and drip irrigation is recommended. Irrigation water should not be drawn from a surface water source as it may be infested with Phytophthora spores. Widespread studies conducted in Michigan have clearly shown that many sources of surface water are contaminated with this long-lasting, devastating pathogen. As a result, progressive growers have moved away from using surface water for irrigation and use only well water to irrigate their crops. While drilling wells is expensive, spreading P. capsici over susceptible crops and introducing it to clean fields also has very expensive ramifications.
If Phytophthora is recognized and diagnosed in the field during production, remove the diseased plants and the surrounding healthy-looking border plants immediately. Growers who have successfully managed this disease have seen benefits to plowing under the portions of their fields with Phytophthora including a buffer of healthy plants, to create a “firewall” between the problem area and the rest of their healthy crop. Make sure to clean any equipment used in the field to prevent spread to other areas, and discard the infected fruits in an area where crops are not going to be grown. Power washing equipment to remove soil particles and plant debris will be helpful in limiting the movement of Phytophthora from
Horticulture Growers' Short Course 73 Field Vegetables
problem fields to clean fields. If you do not have a history of P. capsici in your fields, do everything you can to prevent it from occurring. If P. capsici is present in a field, scout often for disease, rotate only with nonsusceptible crop hosts, and irrigate conservatively from a well. Alternate among fungicides to decrease the likelihood of the pathogen from becoming resistant.
Table 3. Summary of recommended management strategies for P. capsici on pumpkins and vine crops. ● Plant into well-drained, tiled fields. ● Use raised beds and drip irrigation. ● Avoid using surface water for irrigation. ● Irrigate sparingly from a well. ● Keep fruits off of the ground. ● Rotate crops. ● Scout fields regularly for Phytophthora. ● Do not dump diseased culls in production fields. ● Apply fungicides preventively and at short intervals when ● Remove fruits from the field as quickly as possible and store needed. in a warm, dry place. ● Powerwash equipment after it has been in infested fields. ● Remove any diseased plants and adjacent healthy plants.
Table 4. Products tested for control of P. capsici in 2013 MSU research field studies. Product Active ingredient Labeled FRAC1 Actinovate AG Streptomyces lydicus yes NC Bio-Tam Trichoderma asperellum, T. gamsii yes NC DPX-QGU42 experimental no NC Presidio 4SC fluopicolide yes 43 Revus 2.09SC mandipropamid yes 40 Serenade Soil Bacillus subtilis yes NC 1NC=not classified.
For most crops, applying fungicides for control of Phytophthora through trickle irrigation (if allowed per product label) is helpful to protect the plants but foliar applications will be needed later as the fruits develop, especially if the fruits lay on the soil surface in possible contact with the pathogen. Many hard squash and pumpkin plants produce large, dense canopies and proper application equipment is usually required to achieve adequate protection of the fruits. Air-assisted nozzles can help to push the fungicide through the canopy more effectively than conventional nozzles. Several fungicides are registered for use on hard squash and pumpkin (Table 4). In Michigan, some growing areas have fields with P. capsici isolates that are insensitive to the fungicide mefenoxam (Ridomil Gold, Ultra Flourish).
Tomato Diseases
Tomato crops grown in the Great Lakes region includes both fresh market and processing types of production. Each production type has recurring problems with foliar blights and fruit rots. The tomato foliage and the developing fruits are susceptible to fungal and bacterial pathogens which can cause complete yield loss if left unmanaged. These diseases can defoliate the plants resulting in yield loss and also infect the fruits with unmarketable blemishes. Bacterial disease can pit the tomato fruit skin which makes it difficult to peel the fruits for processing. Control of these foliar and fruit diseases can be challenging as the pathogens are favored by warm and humid weather which is common in the Great Lakes region. Many of the pathogens can be seedborne and disease may start in transplant greenhouses and go undetected until established in the production field.
Fungal Diseases
The most common fungal diseases in the Great Lakes tomato production region are early blight (Alternaria solani), Septoria blight (Septoria lycopersici), late blight (Phytophthora infestans), and anthracnose (Colletotrichum coccodes). It is common for both the early and late blight to infect both the foliage and fruits. Septoria only causes foliar blight while anthracnose primarily forms a lesion on ripening fruits. Rhizoctonia solani can cause a rot on fruits when they are exposed to splashing soil or come into direct contact with the soil.
Horticulture Growers' Short Course 74 Field Vegetables
The first management practice is to use disease-free transplants to establish production fields. Proper sanitation of the greenhouse, benches, trays, and planting equipment can help limit new infections on young plants. Avoid overwatering the young transplants and try to keep the greenhouse dry and vent out humid air when possible. Applications of fungicides registered for greenhouse use can help limit the amount of fungal infections on the transplants.
Field plantings should utilize a program of crop rotation to reduce initial disease inoculums that can survive on tomato plant debris from a previous crop. Avoid planting in the same field several years in a row in order to break the disease cycle. Keeping leaf wetness moisture to a minimum can also help reduce disease in a field planting. Try to avoid irrigation events that prolong wet foliage into the evening or early in the morning. There are many effective fungicides that can control the various fungal diseases (Table 5). Starting fungicide applications before disease is established is more effective than waiting until an epidemic starts. Adjust the amount of gallons per acre (GPA) to maximize coverage of all the foliage and to avoid runoff of the spray mixtures. Use proper nozzles for the GPA selected for the fungicide application that will ensure proper coverage and the right spray droplet size for maximum coverage.
Table 5. Efficacy of registered fungicides/bactericides based on MSU research studies. Early Late Bacterial Chemical Active ingredient Septoria Anthracnose blight blight diseases Bravo, Equus, Echo chlorothalonil B+ A A A NA Manzate, Dithane mancozeb B C B B NA Quadris, Flint, Cabrio stroblilurin A B A A NA Endura boscalid A D NA B NA Kocide, Champ copper hydroxide C C C C B Tanos famoxadone/cymoxanil C B NA NA C Oxidate hydrogen dioxide NA NA NA NA NA Serenade Bacillus spp. D NA NA NA D Actigard acibenzolar-s-methyl NA NA NA NA B *A= Excellent control of the disease, B=Good to fair control, C=Fair control, D= Poor control, NA= Not advisable or no control.
Bacterial Diseases
Bacterial spot, bacterial speck, and bacterial canker of tomato appear regularly in Michigan. Each disease can affect plant productivity, reduce yield, and/or cause fruit disorders. Disease management is similar for all three diseases. First, tomato transplants must be disease-free. This may be accomplished by using disease-free seed grown under a strict sanitation regime in the greenhouse.
Bacterial speck is probably one of the easiest bacterial diseases to identify. Small dark-brown spots occur on the leaves with each spot surrounded by a yellow “halo.” Typically just a few plants within a flat show symptoms initially. Although bacterial speck may not produce the panic that the other bacterial diseases do, speck can result in significant yield losses if the blossoms become infected.
Bacterial spot on transplants is not as easy to identify as bacterial speck. Bacterial spot causes larger spots or blotches on the leaves and stems than bacterial speck. The spots may have tan centers and are a maximum of ¼" in diameter. However, some years these spots/lesions may be very dark in color. Michigan growers can experience significant yield losses and devastating fruit spotting due to bacterial spot.
Bacterial canker symptoms on tomato depend on the age of the plant when infected and weather conditions. When infected at a young age, plants can wilt and die. Less severe infections on transplants include blistering on the petiole and browning on the midvein. Infected transplants can also appear healthy and not show symptoms. On older infected tomatoes, sometimes the leaflets wilt on one half of the petiole, while the other leaflets remain healthy. Cankers can occur on stems and often occur after
Horticulture Growers' Short Course 75 Field Vegetables
wilting is seen. There can also be browning of the leaves, especially around the margins; this is commonly referred to as the “firing stage” of the disease. When the stem of an infected plant is cut open, a slight browning or discoloration of the internal tissue is often seen; internal tissues of advanced cases are greatly deteriorated and cavities are formed. Infected fruits have birds-eye spotting which starts as small, white dots. As the spots get larger, the centers die and turn dark, giving a “birds-eye” effect. Plants infected with bacterial canker do not always show these fruit lesions. While it may be difficult to diagnose bacterial canker based on any one symptoms (except birds-eye lesions), when two or more of these symptoms appear in a plant, they are likely the result of bacterial canker infection and identification should be made through isolation of the bacterium.
Plants showing symptoms of bacterial disease and those immediately adjacent to them should be immediately removed from the greenhouse and destroyed. In some situations, all of the plants will have to be destroyed. Unfortunately, if the disease begins in a flat that is too far from the walkway to be seen easily, the disease may go undetected until several flats are severely infected. Epidemics may seem to appear overnight, but chances are it had rather humble beginnings in just a few plants and simply progressed unnoticed for several weeks. Plug sheets containing infected transplants should not be reused. Removing infected transplants from the greenhouse is the most critical component of managing bacterial diseases once they’ve been introduced. Planting diseased transplants into the field ensures that the disease is established early with the greatest potential for yield and quality reduction if the environment favors the disease. Planting infected plants in low tunnels can result in very early defoliation.
Tomato plantings should be rotated. Do not include any other solanaceous crop such as pepper in your rotation program. Although it is widely thought that the bacteria cannot live in the soil, they can survive on tomato debris, especially debris on the soil surface. Two to three years is a rule of thumb to allow such tomato debris to break down. Weeds, especially solanaceous weeds such as nightshade and horsenettle, should be controlled around the fields. Although it is suspected that the bacteria that cause disease on tomatoes survive on weeds, the importance of weeds as a source of inoculum is not known.
Once a greenhouse or field is contaminated with bacteria, steps must be taken to assure that future crops remain disease-free. If a greenhouse is contaminated, remove all plant material from the greenhouse (including weeds and dead plant tissue on the floor), wash and disinfect floor surfaces, hoses, equipment, etc. with a 10% solution of bleach or a commercial disinfectant (GreenShield is an example). Wooden structures such as benches or trays should be soaked in a disinfectant such as bleach (10%) or GreenShield for a minimum of an hour and preferably overnight. A simple washing of wooden surfaces is inadequate because of the cracks and crevices that may allow the bacteria to escape a surface wash. Bacteria that overwinter on a wooden surface may be carried to the plants in water droplets next season during the splashing of overhead irrigation.
A contaminated field should be rotated out of tomatoes for at least three years. At one time it was believed that a rotation of at least five years was necessary, however, it is now known that the level of bacteria in a contaminated field drops dramatically after the first year of rotation. Any equipment used in the problem field should be washed and disinfected prior to entering a clean field. Equipment and workers should begin work in the cleanest field and finish with the contaminated field.
Avoid working in a diseased field when it is wet to avoid spreading the disease. Bacteria may enter the plant through natural openings, or wounds created by wind, pesticide spraying or insects. A film of water on the leaf surface allows the bacteria to remain viable and move. If workers are moving within a wet field and creating new wounds on the plants, new infections are likely. If plants have been staked, all stakes should be treated as discussed previously for wooden trays and benches.
Horticulture Growers' Short Course 76 Field Vegetables
Carrot Diseases
Foliar Blights
Because high humidity and frequent rainfall or irrigation is common during the growing season, yield- threatening foliar blights are a recurring problem for carrots in Michigan. Each year, foliar blights caused by fungi (Alternaria dauci, Cercospora carotae) and/or bacteria (Xanthomonas campestris pv. carotae) reduce photosynthetic area and weaken leaves and petioles. Michigan growers harvest carrots mechanically and weakened foliage can disrupt harvest due to carrot tops breaking off during lifting, leaving the roots in the ground. In situations where foliar disease is severe and not controlled, the tops may be compromised to the extent that the crop cannot be harvested. Therefore, fungicides currently play a critical role in the management of foliar diseases.
Bacterial leaf blight is not a yearly problem for Michigan growers but when present, can be severe in some fields and is A B capable of causing large field losses. Symptoms for this disease (Fig. 3) include dark blighting on leaves and roots. Dark streaks may form on the petioles. In Michigan, early symptoms of bacterial blight may mimic those of Alternaria leaf spot. The bacterium can occur on the seed and can also survive in soil when there is carrot debris. It is thought that the bacteria can survive in carrot debris for one year. Once the carrot debris decomposes, the bacteria cannot survive in the soil. The bacteria spread within a field by rain or overhead irrigation. Low levels Fig. 3. Bacterial blight on crown and of seed contamination may not result in significant disease and petioles (A) and foliage (B) of carrot. crop loss under dry conditions. However, under hot and wet conditions, even a low level of seed contamination may result in high levels of bacterial blight. It is critical that all carrot seed be assayed for the bacterium and undergo hot water treatment if the bacterium is found. Fields with bacterial blight should be worked under as soon as the crop is harvested so that the carrot debris can decompose rapidly and therefore not allow the bacterium to survive in the soil for an extended period of time. Copper-based products are the only materials that can protect the carrot foliage and limit the spread of bacteria. To be most effective, the copper-based fungicides need to be applied early in the growing season and reapplied frequently especially at the beginning of the season until it can be determined whether there are bacteria active in the field (based on visual symptoms).
Symptoms of Alternaria leaf spot include dark brown/black spots with yellow margins appearing on older leaves. Petioles may also become blighted. Severe disease results in weak petioles or defoliation. Cercospora leaf spot occurs as small circular brown spots which rapidly enlarge, accompanied by yellow/red discoloration on younger leaves and girdled petioles, resulting in defoliation. Alternaria and Cercospora may occur together and are managed similarly. Methods to reduce disease pressure include planting disease-free seed, following a 2-year crop rotation, minimizing overhead irrigation during warm weather, and applying effective fungicides at appropriate intervals. Methods to effectively schedule fungicide applications according to field scouting and the TOM-CAST disease forecasting system have been developed and have been adopted by many growers.
Carrot research results for Alternaria/Cercospora field trial
Registered fungicides and new products that are not yet registered for use on carrots were included in a field trial in cooperation with a commercial grower to gauge their activity on Alternaria and Cercospora foliar blights (Table 6). Each product was applied every 7 days using 50 GPA spray volume and XR8003
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nozzles. Plots were evaluated for the amount of Alternaria and/or Cercospora infection on petioles and the foliage as well as overall yield.
Table 6. Products tested in the Alternaria/Cercospora field trial.
Product Active ingredient Labeled
Bravo WeatherStik 6SC chlorothalonil Yes
Bravo Top chlorothalonil+difenoconazole No
Cabrio 20EG pyraclostrobin Yes
Endura 70WG boscalid Yes
Flint 50WG trifloxystrobin Yes
Fontelis 1.7SC penthiopyrad No
Inspire XT 7.17EC difenoconazole+propaconazole No
Kocide 3000 46.1WDG copper hydroxide Yes
Omega 4SC fluazinam No
Pristine 38WG boscalid + pyraclostrobin Yes
Quadris 2.08SC azoxystrobin Yes
Quadris Top 2.71SC azoxystrobin + difenoconazole No
All of the products tested were effective in limiting the number of plants infected with Cercospora and the overall severity of disease (see Fig. 4). Bravo WeatherStik applied alone or in alternation with Inspire XT was very effective in limiting the severity of Cercospora on the petioles. The new product Fontelis was also especially effective in limiting Cercospora infections on the petioles. The tested products limited the amount of foliar blight caused by Alternaria compared to the untreated control. The high rate of Fontelis was also effective in limiting Alternaria blight as was the program of Bravo WeatherStik applied alone or in combination with Quadris Top and Inspire XT. Other products that were effective against Alternaria blight included both rates of Omega alternated with Bravo WeatherStik, the lower rates of Fontelis (with or without Activator 90), Flint, and Endura. Kocide 3000 was included in the study to evaluate its efficacy on bacterial blight but that disease did not develop.
Carrot Summary and Recommendation
Currently registered fungicides are capable of controlling both fungal foliar blights when applied either on a 7-10 day spray schedule or when forecasted by the TOM-CAST disease prediction program developed for carrots. Bacterial blight is best controlled by using disease-free seed and implementing an early preventative program of copper-based fungicides when the disease potential for bacteria exists. In addition to using fungicides, selection of carrot cultivars that are tolerant to disease will help limit foliar blight outbreaks. Selecting reliable seed sources that provide clean and disease free seed will also help limit a growers risk to a disease outbreak.
Acknowledgements
This material is based in part upon work supported by funding provided by the Pickle and Pepper Research Committee for MSU/Pickle Packers International, Inc., the Michigan Vegetable Council, and the Michigan Carrot Committee.
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5 Treatments applied at 7-day intervals 4 d severity 3
(1=healthy, bc 2 c a-c a-c ab a-c ab
5=>50 lesions/plant) 5=>50 ab a ab a a a ab Cercospora a 1 50 Bars with a letter in common 40 f are not significantly different
foliar 30
20 e infection(%) b-e a-e c-e
Alternaria 10 a-d a-d a-d a-d de a-d a-d ab ab a-c a 0
Untreated control Flint 50WG 0.19 lb Fontelis 1.67SC 1 pt Cabrio 20WG 0.75 lb Fontelis 1.67SC 1.5 pt Endura 70WG 0.28 lb Fontelis 1.67SC 0.63 pt Quadris 2.08SC 0.56 pt Kocide 3000 46.1DF 1.5 lb Bravo WeatherStik 6SC 2 pt
Omega 4SC 1 pt -alt- BravoWS 2 pt Omega 4SC 1.5 pt -alt- BravoWS 2 pt
Bravo Top 4.6SC 1.5 pt -alt- BravoWS 2 pt Inspire XT 4.17EC 0.44 pt -alt- BravoWS 2 pt Quadris Top 2.21SC 0.63 pt -alt- BravoWS 2 pt Fontelis 1.67SC 1 pt + Activtor 90 8.33SC 1 pt Fig. 4. Foliar disease ratings for fungicide spray trial on carrot.
Horticulture Growers' Short Course 79 Nursery
Characterization of Rose Black Spot in Canada
Anissa Poleatewich, Irina Perez Valdes, and Rumen Conev Vineland Research and Innovation Centre, Vineland Station, ON [email protected]
Canada has a long tradition in hardy rose breeding, led by Agriculture and Agri-Food Canada (AAFC) from the late 1940’s until 2009. In 2010 the Canadian Nursery Landscape Association (CNLA) acquired the rights to the AAFC selections and partnered with Vineland to lead the research program and continue the tradition of breeding extremely cold hardy roses. The goal of the Canadian Hardy Rose Breeding Program, is to develop a continuous line of cold hardy and black spot resistant landscape, patio and garden roses aligned with consumer preferences. The program utilizes a comprehensive collaborative approach to rose breeding including business development, consumer sciences, classical breeding, bioinformatics and plant pathology.
Vineland’s team carries out over 15,000 controlled crosses every year to combine traits of over 100 parental lines. Between 10,000 and 15,000 hybrids are planted on annual basis in the field in Vineland and individually evaluated for ornamental display and disease resistance for a minimum of 2 years. The top 50 selections per year are then evaluated in the Pan-Canadian testing network consisting of CNLA- member nurseries and academic institutions in British Columbia, Alberta, Manitoba, Ontario, Quebec and New Brunswick. Vineland also has a partnership with the University of Saskatchewan, which operates a test site in one of the coldest areas of urbanized Canada. These annual selections are evaluated for winter hardiness, disease resistance and ornamental display. Following two to three years of rigorous outdoor testing without fungicides and winter protection, the top 1-3 varieties are selected annually for commercialization as of 2019.
Black spot, caused by the fungus Diplocarpon rosae, is a serious disease of roses in the outdoor landscape worldwide. The disease causes black spots on leaves surrounded by yellowing and soon followed by defoliation in susceptible species. Infection weakens the plant leading to fewer blooms and greater sensitivity to other stresses such as winter injury. Susceptibility to black spot is a major challenge to roses and limits their success as low maintenance landscape shrubs. Chemical controls are costly, preventative only and not desirable for use in public places and homeowners do not have access to these fungicides. Thus the disease is best controlled using resistant cultivars. Resistant cultivars are currently available, however resistance is inconsistent depending on the region due to diversity of the black spot pathogen. Within a pathogen population, individuals differ in the ability to attack different varieties. Each group of individuals, able to infect the same set of varieties, make up a pathogenic race. Races of black spot are detected based on which varieties they can infect. The varieties used to identify races are known as differential varieties. To date there are 11 described races of D. rosae, which occur worldwide and are differentiated on a set of 9 cultivars (Whitaker et al, 2010). Knowledge of black spot races is important because currently there is no rose cultivar which is resistant to all of the 11 races. This is why there may be a cultivar which performs well in Europe, but is susceptible to disease in North America. As a result, knowledge of race distribution is needed to breed for resistance to races found in specific growing regions and target markets. To date, there is limited knowledge of geographic distribution of races worldwide.
Roses are typically evaluated for resistance in field trials which are subject to the amount of disease and the races present at the location. Often the pathogen population in the field is not known and race-specific resistance cannot be specified. At Vineland our goal is to build a foundational resource of black spot single spore isolates to be used in the rose breeding program and to characterize the predominant races in Canada. To achieve this, Vineland will collect black spot infected material from 10 sites across Canada,
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isolate individual black spot spores and characterize the isolates on the differential varieties. Black spot infected leaves are collected and processed to identify unique isolates in a series of steps (Figure 1). Because one plant may contain a mixture of races, single spores are obtained and race tested individually.
Figure 1. Procedure used to process black spot infected leaves and identify unique isolates.
Once single spore isolates have been obtained, the isolates are inoculated onto detached leaves of the 9 differential cultivars. Two leaves of each differential cultivar are placed in humid chamber. A spore suspension is applied to each leaf and the leaves are incubated at room temperature for 2 weeks. A variety is considered susceptible if spore-bearing lesions develop on at least one leaflet (Figure 2). This test is repeated 3 times. To date, we have collected 35 black spot isolates from the Vineland farm and identified the presence of races 8, 10 and 11. We have also found isolates that do not match the infection pattern of any known black spot races and we suspect these represent new, previously uncharacterized races. Additional research is needed to confirm these findings.
Figure 2. Black spot lesions on detached leaves.
Next steps are to continue to characterize black spot isolates collected in Ontario and to continue sampling across Canada. Additionally, once predominant races have been identified, the plant pathology team at Vineland will determine race-specific resistance of the top selections in the breeding program using the detached leaf assay described above.
References
Whitaker, V. M., T. Debener, et al. (2010). "A standard set of host differentials and unified nomenclature for an international collection of Diplocarpon rosae races." Plant Pathology 59: 745-752.
Horticulture Growers' Short Course 81 Nursery
What is All the “Buzz”: Systemic Insecticides and Pollinators
Raymond Cloyd Kansas State University, Department of Entomology, Manhattan, KS [email protected]
Systemic insecticides are a group of insecticides that when applied to the soil or growing medium, the active ingredient is taken up by the root system and translocated or distributed throughout the plant. Systemic insecticides are primarily used to control or suppress populations of phloem-feeding insects such as aphids, whiteflies, mealybugs, leafhoppers, and soft scales. There are a number of methods by which systemic insecticides can be applied, including foliar, soil or growing medium drench, granular, soil injection, trunk injection, and chemigation. The benefits of systemic insecticides include the following:
• Plants are protected throughout most of the growing season without the need for repeat applications. • Less susceptible to ultra-violet light degradation or rainfall following an application. • Minimal, if any, unsightly residues on leaves when applied to the soil or growing medium. • Plants, in general, are less harmful to workers and customers when compared to plants that receive spray applications of an insecticide. • Negligible issues associated with drift compared to foliar sprays. • Minimal direct impact on natural enemies (e.g., parasitoids and predators) and bees.
The currently available systemic insecticides in the USA are acephate (Orthene), flonicamid (Aria), pymetrozine (Endeavor), chlorantraniliprole (Acelypryn), cyantraniliprole (Mainspring), imidacloprid (Marathon/Merit), acetamiprid (TriStar), dinotefuran (Safari), thiamethoxam (Flagship/Meridian), clothianidin (Arena), and spirotetramat (Kontos). The predominant systemic insecticides being used on greenhouse and outdoor grown horticultural crops are the neonicotinoids, which include imidacloprid, thiamethoxam, acetamiprid, dinotefuran, and clothianidian. Nearly all of the neonicotinoid systemic insecticides that are labeled for applications to the soil or growing medium are converted into metabolites, which are actually more toxic to insect pests than the parent compound. Below are the active ingredients of several neonicotinoid systemic insecticides and their subsequent metabolites: • imidacloprid=olefin, and 4- and 5-hydroxy • dinotefuran=UF metabolite • thiamethoxam=clothianidin
So, what are the issues associated with systemic insecticides and pollinators? First of all, do bees and other pollinators use greenhouse and nursery grown horticultural crops as a food source? There are concerns regarding this and subsequent questions pertaining to the effects of systemic insecticides on pollinators; however, the main concern is associated with exposure to contaminated pollen and nectar that may lead to direct, indirect, or sublethal effects on bees (and other pollinators). Since systemic insecticides may be absorbed into the plants, the active ingredient or metabolites may be present in pollen and nectar thus making floral resources (flowers) toxic to pollinators during feeding. Therefore, any residues of systemic insecticides present in pollen and nectar may be consumed by pollinators, and the residue concentrations may reach levels that are either lethal or sublethal (or have no effect).
It is important to note that the European honey bee (Apis mellifera) is not native to the USA; however, it is an important pollinator for agricultural and horticultural crops, pollinating >130 crops at a value of $15 to $20 billion per year in the USA. Moreover, honey bees have experienced a number of factors that have resulted in honey bee colony losses. These so-called “stressors” include 1) the varroa mite (Varroa
Horticulture Growers' Short Course 82 Nursery
destructor), 2) lack of nutritious summer foraging locations, 3) pesticides, 4) poor nutrition, 5) habitat fragmentation/destruction, 6) diseases (e.g., Nosema ceranae), 7) poor bee husbandry, 8) long distance transportation, 9) genetically modified crops, and 10) interactions among these factors.
An important question is how long do residues last after an application of a systemic insecticide is made (nursery to purchase and then installation)? Furthermore, below are some general comments and questions associated with the impact of systemic insecticides on pollinators: • Can systemic insecticides be absorbed into plants and become present in pollen and nectar, thus making floral resources toxic to pollinators? • Are systemic insecticides present in pollen and nectar at concentrations that cause lethal or sublethal effects? • Will contact with systemic insecticides result in lethal, sublethal, or no effects? • Will exposure to systemic insecticides increase pollinator susceptibility to parasites (e.g., varroa mite) and/or pathogens (e.g., Nosema ceranae)? • What about interactions and multiple factors? For example, what about the effect of combination products and interactions with fungicides? • The timing of application influences the potential concentration of residues in flowers. Residues may occur at higher levels in pollen and nectar when applied before or during flowering. • What about the effects of metabolites and are they present at toxic levels in pollen and nectar? • Any variations in the uptake of systemic insecticides during flowering may strongly effect the concentration in pollen and nectar.
Furthermore, there are many factors that may influence the variation of residue levels in pollen and nectar including 1) timing of application, 2) application method, 3) application rate, 4) number of applications (carry-over), 5) formulation, 6) water solubility, 7) plant type and flower morphology, 8) plant age and size, 9) soil type (and organic matter content), 10) environmental conditions (e.g., temperature, rainfall, and light intensity), and 11) bee age and size. Also, honey bees are able to forage two to four miles from a hive, and gather pollen and nectar from a wide-range of flowers during the season thus possibly diluting contaminated pollen and nectar by collecting from different types of flowers.
The impact of systemic insecticides on bees is not a new phenomenon as this has been known since the 1960’s. For example, a scientific peer-reviewed publication from 1968 stated “Death of bees following the application of insecticides may be due to direct contact with the spray and/or residues remaining on the surfaces of plants, or even direct contamination of pollen. Systemic insecticides may be harmful due to their translocation into pollen and nectar, which may be toxic to bees.” (Lord, K. A., M. A. May, and J. H. Stevenson. 1968. The secretion of the systemic insecticide dimethoate and phorate into nectar. Ann. Appl. Biol. 61: 19-27).”
There is no doubt that we need to preserve our pollinators—but we also need to exercise “common sense”. The questions that need to be addressed are: will banning systemic insecticides really help to preserve pollinators? What will be the repercussions of not being able to use systemic insecticides? How will this help pollinators? So, where do we go from here? Here are four factors that must be considered in order to protect our pollinators: • Use pesticides according to the label. • Apply pesticides when bees and other pollinators are not active (early morning and/or late evening). • Apply more selective pesticides or those that are less harmful to bees and other pollinators. • Exercise caution when applying any pesticide (do not apply pesticides to open flowers).
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Two resources that provide additional information on the impact of pesticides on bees and pollinators: • The Xerces Society Guide To Attracting Native Pollinators: Protecting North America’s Bees And Butterflies. 2011 (www.storey.com) • The Bee: A Natural History. 2014. Noah Wilson-Rich. Princeton University Press (press.princeton.edu)
Horticulture Growers' Short Course 84 Nursery
Drip Irrigation of Nursery Crops
Inge Bisconer Toro Micro-Irrigation, Abbotsford, BC [email protected]
Introduction
There are many advantages to drip irrigation, including improved crop quality and uniformity, conservation of resources and enhanced stewardship. The use of drip tape and driplines to efficiently irrigate field-grown and containerized nursery stock is the subject of this presentation which will include a review of the advantages of drip, an overview of lateral and submain options, pictures of field examples, information on drip irrigation system uniformity, an overview of an article called “Watering for Success” published in American Nurseryman, and sources of more information.
The Advantages of Drip Irrigation
Micro-Irrigation, also commonly called drip irrigation, was commercially introduced over four decades ago and is growing rapidly. National Geographic scholar Sandra Postel recently estimated that well over 25 million acres are irrigated with drip micro irrigation worldwide: (http://voices.nationalgeographic.com/2012/06/25/drip-irrigation-expanding-worldwide/).
Horticulture Growers' Short Course 85 Nursery
As summarized in the preceding “Benefits of Drip Irrigation” illustration, documented case studies have shown that farmers adopt drip irrigation for a variety of reasons, including improved crop response from the spoon feeding of water and nutrients directly to the crop rootzone, and improved resource use efficiencies. These benefits often boost farm income and reduce irrigation related production costs enough to pay for the investment quickly. In addition, runoff, wind drift and deep percolation of irrigation water is minimized, and access to the field is improved compared to other irrigation methods. The advantages of drip irrigation in comparison with sprinklers and hand watering for nursery crops can be summarized as follows:
Comparing Drip/Micro, Sprinkler and Hand Watering Irrigation Drip/Micro Sprinklers Hand Water Ability to "spoon feed" crop High Low Low via automation Ability to fertigate High Low Low Operating labor intensity Low Low High Typical system uniformity High Medium Low Ability to keep non-targeted High Low Medium areas dry Ability to avoid runoff or High Medium Medium deep percolation System application rates Low Medium High Likelihood of wetting plants Low High High Energy costs Low High Low System purchase and High Medium Low installation cost
Overview of Drip Tape and Dripline Irrigation Systems
Drip irrigation systems consist of blocks of lateral pipes with online or inline emission devices that emit water directly to the root zones of crops or to crop containers. Water and liquid nutrients are supplied to these laterals through networks of submain and mainline pipelines as shown in the “Typical Drip System Layout” illustration on the following page.
This presentation focuses on the use of drip tape and dripline laterals supplied by polyethylene or PVC submains for field-grown and containerized nursery stock. The following provides a description of the different types of laterals and submains commonly used in these applications, as well as a description of emission device flow exponents which influence system uniformity and overall application rate flexibility.
Horticulture Growers' Short Course 86 Nursery
Laterals
• Drip tape is a “line source” drip irrigation lateral that incorporates a continuously produced flowpath emission device into a thin- to medium-walled seamed or extruded tube. Toro’s Aqua- Traxx premium drip tape with the PBX advantage is an example of an extruded drip tape with rotary molded emitters using a polyethylene flowpath, while Toro’s Aqua-Traxx FC is constructed from an elastomeric material that provides flow control benefits.
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• Thinwall, flat emitter dripline is a “point-source” lateral product that incorporates injection molded emitters into a thin- to medium-walled extruded tube. Toro’s Neptune flat emitter dripline is an example of this type of lateral. • Heavy-wall dripline consists of small plastic emission devices similar in function to on-line emitters, but in this configuration they are pre-inserted into the polyethylene tubing at specified intervals during the tubing extrusion process. The emitters may be cylindrical or flat “boat shaped”, and are attached to the inner tube wall via a controlled heating/adhesion process. Toro’s BlueLine Classic and PC (pressure compensated) are examples of heavy-walled dripline.
Submains
• Oval hose is a submain pipe made from polyethylene (PE) that is flattened to an oval shape during production to improve transportability. • Layflat is a submain pipe made from flexible PVC that is coiled flat. • PVC pipe is rigid and available in various thicknesses and cut lengths.
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Emission Device Flow Exponents
Drip irrigation emission devices, or emitters, are categorized by their flow exponents which describe their ability to regulate flow in relation to pressure. The flow exponent X of emission devices is important to irrigators and producers because it influences the distribution uniformity of emitters within an irrigation block, and also influences the emitters’ level of responsiveness to changes in system inlet pressure to adjust the system application rate. The majority of the market uses emission devices with either a flow exponent of ~0.5 or a flow exponent of ~0.1, each category having relative advantages and disadvantages. Toro’s recently released Aqua-Traxx FC Flow Control premium drip tape (ATFC) incorporates flow control emitters with an exponent of ~0.3 which provide improved flexibility to adjust application rates compared to pressure compensating emitters with a flow exponent of ~0.1, and better distribution uniformity between emitters in a block compared to standard turbulent flow emitters with an exponent of ~ 0.5. The following illustrates emitter types, the flow exponent x value, and typical flow vs. pressure curves.
Field Examples
The following photographs show greenhouse grown Asiatic lilies irrigated with drip tape, citrus nursery stock irrigated with flow control drip tape, and field grown tree and shrub stock irrigated over-the-pot with drip tape and dripline. More field examples are available in the PowerPoint presentation that accompanies this paper.
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Drip Irrigation Uniformity
Irrigation system uniformity tells how evenly water is applied throughout the block and indicates how much over-irrigation must occur to ensure the driest part of the block receives enough water and nutrients to support the crop i.e., how much over-irrigation will be required to compensate for imperfect uniformity. Drip irrigation uniformity is typically expressed as distribution uniformity (DU) or emission uniformity (EU), either as a decimal or a percentage. A system’s uniformity at the time of design is considered theoretical “design uniformity”, while measured uniformity in an operating drip system is considered actual “field uniformity”. The system’s gross application rate is usually stated in GPM or inches per acre, and once known it is downgraded by the system’s uniformity to determine the net application rate for irrigation scheduling purposes.
How is it Determined?
Drip irrigation uniformity may be predicted by the designer, or measured in the field. The predicted design uniformity is a result of the designer’s component selection, sizing and layout considering block shape, size and topography. Since flow is directly affected by pressure, and pressure is directly affected by topography and friction loss through pipelines, uniformity is best when pressure variation within the block is minimized, or when components are selected that minimize sensitivity to pressure variation.
Measured uniformity in the field is the result of design uniformity after installation and under actual operating conditions. This includes the effect of water quality and actual system pressure and flow. For example, if emission device clogging is occurring due to poor water quality or lack of system maintenance, if there are leaks in the mainline, submains or laterals due to poor installation or field
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damage, and/or if system operating pressures are not maintained within the design operating window, then field uniformity will be lower than predicted uniformity. Field uniformity may be determined by taking flow measurements from a number of emission devices within the block and then dividing the average measurement of the “low quarter measurements” (lowest 25% of the readings) by the overall average.
Why is Irrigation Uniformity Important?
Irrigation uniformity is important because it directly affects crop performance, operating costs, and control of applied water and nutrients to the environment. One of the main advantages of drip irrigation is the opportunity to obtain high system uniformity. In general, drip irrigation systems often achieve over 90% uniformity with proper design, installation, operation and maintenance. This is in contrast to typical uniformities of 40-60% for gravity systems and 50-75% for sprinkler systems. To help translate the importance of uniformity, the following table illustrates how many hours are required to apply a minimum of 1.0 inch of water to all plants in an irrigation block assuming various emission uniformities and assuming an application rate of 0.10 inches per hour.
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Hours of Net Application Increase in Block Emission operation to Rate*, Runtime to apply Uniformity, % apply 1.0 inches/hour 1.0 inches inches 100% 0.100 10.0 0% 95% 0.095 10.5 5% 90% 0.090 11.1 11% 85% 0.085 11.8 18% 80% 0.080 12.5 25% 75% 0.075 13.3 33% 70% 0.070 14.3 43% 65% 0.065 15.4 54% 60% 0.060 16.7 67% 55% 0.055 18.2 82% 50% 0.050 20.0 100% * Assumes gross application rate of 0.1 inches per hour.
Note that if the drip irrigation system were perfectly uniform (EU = 100%), then the system would need to run 10 hours to apply 1.0 inch of water, whereas if the system had an EU of 50%, then the system would need to run twice as long, 20 hours, to apply a minimum of 1.0 inch of water to the driest part of the field. Running the system twice as many hours means twice as many gallons of water and fertilizer applied, twice as much fuel use and more labor expense to achieve the same result: applying 1.0 inch of water. Another way to view this is as a percent increase in runtime as shown below, where, for example, a 75% EU results in the necessity for a 33% increase in runtime:
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Perhaps more importantly, in addition to avoiding the costs associated with unnecessary system runtime, high drip irrigation uniformity leads to more uniform crop production and enhanced crop health and vigor since all plants in the block receive the proper amount of water and nutrients, ideally at the right time. As a result, yield and quality are increased while inputs are reduced. Another way of stating this is that water use efficiency, nutrient use efficiency, and/or overall resource use efficiency is improved and more “crop per unit of input” is achieved.
Over the past decades, countless growers and researchers of fruit, nut, vegetable, field and nursery crops have reported and documented increased crop yield and quality per unit of water, fertilizer, labor and fuel applied with drip irrigation systems. In addition, highly uniform drip irrigation systems provide more flexibility to spoon feed the crop and to target water and nutrients exclusively to the crop rootzone. This helps decrease weeds, pests and disease and the resources typically used to control them, and also helps prevent the application of water and fertilizer where unwanted due to wind drift, runoff or deep percolation beyond the rootzone. As a result, achieving high system uniformity with a well-designed, installed, operated and maintained drip irrigation systems leads to improved farm profits and more sustainable farming practices.
How can Drip Irrigation Uniformity be Maximized?
Drip irrigation uniformity may be maximized with proper design, installation, operation and maintenance. Although all irrigation system types share some basic hydraulic principles and equipment, such as pumps and delivery pipe, drip irrigation systems require specialized knowledge to choose the right types and sizes of system components to ensure that the system applies water uniformly to each plant, and so that the system may be flushed and maintained to ensure a long life. Prior to the availability of software, designers manually calculated system hydraulics including friction loss and flow uniformity, or they used charts and nomographs developed for this specific purpose. With the introduction of consumer computers, early versions of drip irrigation design software automated many of these tasks and allowed a higher level of accuracy.
Today, drip irrigation design has never been easier or more accurate. Toro’s AquaFlow drip irrigation design program takes advantage of recent advancements in computer processing, programming techniques and display screen technology to optimize drip irrigation design. Designers can now evaluate more selection options more quickly, and with more accuracy than ever before, thus improving the decision-making process for selecting drip irrigation system components. This results in higher uniformity and better, more cost effective drip irrigation system performance which improves the return on investment (ROI) for the farmer.
The figure below shows two of AquaFlow’s Uniformity Maps that illustrate drip irrigation block uniformity with color where highly uniformity blocks have fewer colors. For example, the uniformity map on the left used Aqua-Traxx Classic drip tape and has more colors, and lower uniformity, than the uniformity map on the right which used Aqua-Traxx FC flow control drip tape. Each design used a drip tape with the exact same flow rate, spacing, internal diameter and length of run under the same topography and with the same submain supply, but since Aqua-Traxx FC has superior hydraulic performance than Aqua-Traxx Classic, the resulting block uniformity is improved using Aqua-Traxx FC. Thus, with all other variables remaining constant, the choice of drip tape alone can significantly affect drip irrigation system uniformity.
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In addition to design, system installation, operation and maintenance are also extremely important. Even though recent innovations in drip irrigation component design and manufacturing have made clog- resistant, highly uniform drip tapes, dripline and other emission devices readily available, the nature of agricultural water sources, fertilizer injection practices, natural limitations of filtration equipment and the general agricultural growing environment make maintenance a priority. Toro’s Drip Irrigation Owner’s Manual helps growers understand system set-up, irrigation scheduling, fertilizer application and system maintenance including flushing and chemigation.
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Because significant portions of drip systems are buried and can’t be easily viewed, monitoring the drip system status with pressure gauges and flow meters is the key to ensuring high uniformity and diagnosing problems. After the system has been connected, flushed and pressure-tested with control valves properly set — and it’s been verified that all underground components are working properly — baseline pressure readings should be taken before and after the filter, before and after the block control valves, and at the end of some lateral lines to ensure the system is operating as intended. In addition, the system flow rate should be routinely monitored at the pump station, and the condition of flush water from the ends of laterals and submains checked regularly to trigger flushing and chemigation events.
In summary, high drip irrigation uniformity may be achieved and maintained over many years with proper design, installation, operation and maintenance. With highly uniform drip irrigation systems, farmers may efficiently spoon feed their crops water and nutrients to achieve higher, more uniform yields with fewer inputs. This results in improved farm profits, more food production with fewer inputs, and more sustainable farming practices.
Watering for Success Article
In December, 2007, American Nurseryman published an article called “Water for Success” written by Inge Bisconer of Toro Micro-Irrigation. The purpose of the article was to help growers produce better plants - while saving money and resources – by learning the ins and outs of irrigation management. The article may be accessed at driptips.toro.com – a summary of its contents are as follows:
The key points of the article were: • Irrigation management is important. • Ensure that the system applies water uniformly. • Automate to ensure proper timing of irrigations.
The following points were made regarding why irrigation management is important: • Avoid wasting costly water, fertilizer, fuel and other inputs. • Reduce labor if automation employed. • Increase income if production improved. • Better stewardship and compliance with regulations concerning runoff and deep percolation.
The article lists the following basics of irrigation management: • Know the crop water requirement: ♦ Inches per acre. ♦ Gallons per plant. • Know the soil: ♦ Ability to receive water. ♦ Ability to hold water. • Know the irrigation system: ♦ Application Rate. ♦ Uniformity. ♦ Simple system audit/evaluation. ♦ System maintenance. • Scheduling: How much, how often? ♦ Irrigation.
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♦ Cooling. ♦ Propagation. • Why automate? ♦ Avoid waste. ♦ Save labor. ♦ Optimize timing, production. • How to automate? ♦ With power. ♦ Without power.
Further Resources
In summary, drip irrigation provides valuable benefits for producers of nursery crops. For more information, please visit Toro’s websites for free ROI and design software, case studies, educational books and manuals, videos, archived webinars, financing information, newsletters, blogs, social media links and product information.
Learn more: toro.com | driptips.toro.com
Horticulture Growers' Short Course 97 Farm-Direct Marketing
Opening Remarks for Direct Marketing Session
Murray Siemens Fraser Valley Farm Direct Marketing Association, Willow View Farms, Abbotsford, BC [email protected]
This past year was very successful for many of us in direct marketing, partly because of the good summer and fall weather, but also due to the growing interest in local food and meeting the farmers who produce it.
Trends
• Continuing interest in buying local. • Local is the new “organic”. While organic is still growing quickly, some of the lustre has come off organic products. This is likely due to large companies getting involved and sourcing products from far away, as well as some confusion over certification. Local and organic is probably the sweet spot in marketing. • Events on the farm. People are looking for unique venues for festivals, weddings and corporate picnics. • Experiential travel. It’s not just about buying stuff, which used to be the (North) “American Dream”. People want to have experiences with family and friends. They want to travel and share with their “tribe” via Facebook, Instagram, and Twitter. • Rise of food shows, foodies, and food blogs. Try to get these people to share their farm experiences and their “discovery” of your farm products with their followers. One caveat, while people are interested in “slow food” and elaborate menus, the reality is that most people still commute, work and have to rush meal preparation. Therefore, products that are easy and convenient still constitute the majority of purchases. • Smart phones and tablets. It seems like everyone has them. I’m getting so used to swiping and tapping that I’m trying to use this technique on everything: my desktop computer, the TV, even the family cat! Make sure your website is smart phone friendly. About 50% of hits are now from mobile devices. If your home page does not load properly, potential customers will “bounce” and not go any further into your site. Lots of opportunity for using QR codes and apps (recipes, maps, etc.).
Winter Work
This is a great time to catch up on paperwork and planning.
Vision: Do you have a vision for your farm or business? If you don’t have a vision, how will you know where you are going?
Elevator Pitch: Credit to Jane Eckert for the idea of developing an “elevator pitch” to be used when you have a short opportunity (like riding in an elevator) to introduce yourself and promote your business. Highlight the best points, explain what is special and unique, and why they might be interested in doing business with you.
Priorities: It’s good to sit down with family or partners and set priorities.
Goals: If you don’t have goals, how do you know where you are going and when you get there? Many businesses set SMART goals:
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Specificwell defined goals. Measurableknow when they are achieved. Agreed uponagreed on by all stakeholders. Realisticrealistic and achievable. Timelyenough, but not too much, time to achieve goals.
Policies and Procedures
As you grow, it’s good to have policies and procedures so tasks get done properly and consistently. They are also useful to show regulatory agencies that you have good practises and are performing due diligence. Food safety, worker safety, customer care and safety are important. We often don’t have expertise in developing this stuff, and if you’re like me, you don’t want to invent what has already been invented.
There are many good websites that have information and templates or samples for this. Worksafe, CFIB, BC and Ontario Ministries of Agriculture, and CanadaGap are a few. A great website that I have recently discovered is SafeAgriTourism.com, it has checklists for food safety, petting zoos, corn mazes, etc. It also has procedure sheets, sample policies, guidelines, and even signs that you can print off.
Horticulture Growers' Short Course 99 Farm-Direct Marketing
Pricing, Distribution & Profitability
Andrea Gray-Grant Gray-Grant Consulting, Inc., North Vancouver, BC [email protected]
My name is Andrea Gray-Grant and I am a consultant in the food industry. I have been asked by the LMHIA to speak on pricing, distribution and profitability. My background of having worked 15 years for some of the most dynamic Canadian and US natural food manufactures gave me a sense of security that I would be prepared to start my own brand, manufacturing facility and co-pack for other companies. I was wrong, and after 5 years in my own manufacturing business, I failed.
The failure was not only incredibly humbling, but I believe it was critical for me to have that experience so that I would be able to help my clients avoid the pitfalls. The learning that I had from building a facility, launching a brand, scaling up products, dealing with quality issues, HR problems and a myriad of other challenges, gave me a truly unique opportunity to see that even with my connections, networking ability, retailer contacts and sales and marketing know-how, it can still be extremely challenging to have a successful manufacturing company.
I have worked with clients from all over BC for the past three and a half years to coach and mentor them in their food processing businesses. I work one-on-one through the Growing Forward 2 initiative with BC Agriculture to provide marketing strategies and coaching to new and emerging brands with the goal of preparing them for all of the challenges of opening or expanding their food processing businesses.
Pricing products is the first lesson I have with my clients. We look at the “Cost of Goods” of the product to be made and then determine its feasibility for retail. Included in the C.O.G.S. is: ingredients, labour and packaging. Once that is determined for each product, we look at ensuring that the client has the appropriate margin on their product. This is before additional costs such as marketing, distribution and various other costs of doing business.
Why margin on products and not markup? In food, we focus on margin because that is what retailers, as well as third-party distributors, use. What is the difference?
Markup is the difference between the cost and the selling price. For example, if you have a product that costs $1 and you sell it with a 40% markup, your selling price is $1.40. The math is simply:
$1.00 x 1.40 = $1.40
Margin on the other hand, is the percentage difference between the selling price and the profit. In this case the math is as follows:
100 – 40 = 60 therefore, $1.00 / .60 = $1.67
If one were to work on markup and not margin, the loss would equal $0.27 cents per unit! Clearly, it is best to work on the same math that the rest of the industry uses.
Once the costs are determined and calculating margin is understood, what would be considered an appropriate margin for a product once the C.O.G.S is considered? Industry standard is 40%. Ensuring that you have a 40% margin once all costs have been determined allows for inclusion of marketing funds to support retail entry and other business costs, such as overhead and distribution.
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The price of the product and appropriate margins are determined and then a distribution strategy must be considered. Should the products go direct to market or through third- party distribution? The benefits of using third-party distribution are: • Distributors buy product directly from the processor and pay within 30 days of receipt of goods. • The Distributor holds the risk of receivables, as they sell to your customers and must also collect from them. • The Distributor has greater coverage with several trucks, than you with limited logistics. • The Distributor has long-standing relationships with retailers that the processor may not have.
The benefits of going direct to retail are: • A processor has the ability to build rapport with their customer. • Information may be passed on to the processor more quicklyquality issues, sales successes or challenges, customer feedback in general. • More profitableno loss of margin due to third-party distribution costs.
The costs must be considered when using third-party distribution because they can be considerable, particularly if you are making a product that requires more care and attention, such as frozen, refrigerated or baked goods. Even with shelf-stable products, 28% would be considered an average margin for a third- party distributor to take. Add to this a retailer margin of around 40% to be safe, and you can determine a very realistic “Suggested Retail Price Point” for your product.
If we look at the $1.00 cost model again for simplicity, let’s consider our cost with 40% margin at: $1.67.
Here is what a pricing structure looks like when third-party distribution is implemented:
Cost with 40% margin = $1.67
Third-party distribution 28% = 100 – 28 = 72 therefore, $1.67 / .72 = $2.32
Retailer Margin on top of distributor cost $2.32 / .60 = $3.87
Suggested Retail Price Point would be rounded up to: $3.89
Ultimately, most of my clients are very surprised at how quickly margin makes a product price rise exponentially. They are also quite shocked with the fact that profit margins at the end of this calculation often end up being between 15 and 20%, and that would be considered a healthy profit!
My council to my clients is: • Understand your costs and know the difference between margin and markup. • Consider not what you do today ( i.e., self-delivery), but plan to have the option of third-party distribution once your sales increase. • Continually strive to better your C.O.G.S., because any small savings translate into stronger margins for processors.
Thank you for inviting me to speak about pricing, distribution and profitability - it truly is the foundation to build a successful food processing business.
Horticulture Growers' Short Course 101 All Berries
The Blueberry Experience with Spotted Wing Drosophila in 2014
Tracy Hueppelsheuser British Columbia Ministry of Agriculture, Abbotsford, BC [email protected]
Spotted Wing Drosophila (Drosophila suzukii) continues to challenge berry growers in southwestern British Columbia. Infested fruit becomes soft, leaky, and has shortened shelf life.
An area-wide trapping survey was done in 2014, as in previous years, in 28 commercial blueberry fields, 4 traps per field, 2 edge traps, 2 middle traps (at least 50 m from field edge), in the Fraser Valley, from Delta to Chilliwack. Traps were set up, maintained, and contents collected weekly from May to September. As in previous years, we used Contech Fruit Fly Traps (Contech Inc.), baited with 30 ml of apple cider vinegar (Heinz). Trends in catches were similar to previous years, with low numbers caught early, then a jump in numbers from mid-July until late August, and then numbers increasing significantly again through September (Figure 1).
Edge traps caught more flies than field middle traps, particularly early (May to mid-June) and late in the season (September). This seems to indicate that SWD are more abundant outside the field edges before crop ripens, and again when harvest is completed (or nearly so).
We started a new project in 2014: dissection of SWD female flies from the Fraser Valley. One of our
Figure 1.
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main questions was: “When do reproductively active (mature) females appear in the populations?” This is when the crops are at risk.
In order to start to answer this question, female flies caught in traps were dissected and their ovaries ranked by age. Ovary ages: Immature (future risk), Mature (Risk now), Old, degenerated (no more risk). What we found in a spring bait trial (April 7-July 7), was that of the two main bait types (apple cider vinegar and a solution of yeast, sugar, water), apple cider vinegar (ACV) traps caught overall higher numbers, and the first fly of the study (April 14). However, many of the flies caught in the ACV were old with degenerated ovaries. Yeast, while it caught fewer overall numbers, caught proportionally more young and active females (those that infer present and future risk to berry crops). Yeast also caught the first ‘mature’ female, a week earlier than ACV. (Figure 2). Therefore, yeast appears to be a good early spring bait for catching reproductively mature females—the ‘risky’ females.
Figure 2.
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Dissections across the entire year revealed that mature flies ready to lay eggs were caught by May 5, well before commercial fruit is available. Wild red elderberry fruit was found to be infested at low levels with SWD by June 6. In summer, it appears that the traps do not compete well with the ripening fruit (July, August), so traps are not really efficient during that time. In the fall, (mid-October to mid-November) many dissected flies were young, which we expect will overwinter and lay eggs in the following spring (May onwards).
2014 was the second year of case studies to try to answer the question: “When should I spray again? 7 days, 10 days, or other?” We chose conventionally managed fields; 3 ‘Duke’ fields, 4 ‘Bluecrop’ fields, and 4 ‘Elliot’ fields in Abbotsford and Langley areas. We were able to go back to many of the same fields as in 2013. The same trends were seen in both years. ‘Duke’ continues to be minimally threatened by SWD, though late ‘Duke’ can have low levels of infestation. ‘Bluecrop’ remains a high risk variety, and diligent management practices are recommended, including timely sprays (every 7 days), timely harvests, and good fruit handling practices to ensure top fruit quality. ‘Elliot’ was less impacted by SWD in 2014 than in 2013. Spray interval could be stretched to 10 days in lower pressure years, or in fields which don’t have a history of SWD.
Stay up-to-date with the summer weekly IPM reports from the BC berry grower organizations, information from the BC Ministry of Agriculture website, and other great sources of information, such as the Small Fruit Update from Oregon.
BC Ministry of Agriculture SWD: http://www.al.gov.bc.ca/cropprot/swd.htm
Acknowledgements
This project was funded in part by the BC Ministry of Agriculture and Agriculture and Agri-Food Canada through Growing Forward 2, a federal-provincial-territorial initiative. Additional support was provided by: Grower/Industry Cooperators, BC Blueberry Council, Raspberry Industry Development Council, Strawberry Growers Association, E.S. Cropconsult Ltd., BC Ministry of Agriculture, Dr. Beverly Gerdeman, Washington State University.
Horticulture Growers' Short Course 104 All Berries
Yellow Nutsedge: An Increasing Weed Threat to Berry Crops
Victoria Brookes Agriculture and Agri-Food Canada, Agassiz BC [email protected]
Yellow nutsedge (Cyperus esculentus) is considered one of the five worst weeds in the world. This weed is relatively new to British Columbia. It has been established in Eastern Canada for some time (there are some reports that it is native to Eastern Canada) and was first found in the 1990’s in British Columbia. It was initially found in blueberry fields in Abbotsford and has now spread to other farms in the Fraser Valley and Lower Mainland. Once established it is almost impossible to eliminate this weed. It was probably introduced by imported contaminated potted plants. Nutsedge is able to grow in a variety of climates.
Other names for Yellow nutsedge include: Earth Almond, Yellow Nutgrass, Coco sedge, Watergrass, Edible galingale, Chufa, Ground Almonds, Northern Nut-grass, Nutgrass, Souchet comestible, Souchet rampant and Chufa flatsedge.
Yellow nutsedge is in the sedge family and is different from grasses. The leaves are thicker and stiffer than true grasses. The leaves are arranged in sets of three at their base. Yellow nutsedge stems are solid and triangular in cross section. Yellow nutsedge has the typical attributes of a successful problem weed (i.e. it is a perennial and can reproduce by multiple methods). It reproduces by tubers, rhizomes and seeds.
Yellow nutsedge overwinters as tubers (sometimes called nuts). The tubers are usually 5 – 20 mm long. A single plant can produce up to 7,000 tubers and can spread over one metre in a year. The tubers can also stay dormant in the soil for years. A local Delta grower put an infested area into a green cover crop for 7 years and didn’t see any nutsedge growth. After 7 years the field was cultivated and planted to a crop and the nutsedge tubers that had been suppressed by the cover crop began to grow again.
Herbicides in Berry Crops for treating Yellow nutsedge
Basagran + Assist Oil for Highbush Blueberries • When the trial work was first started in 1996 the plots had to be placed around the field as nutsedge was only occurring in random places. The final year of trial work was 1998, and by that time nutsedge had established throughout the field. • Basagran + Assist Oil can be effective for nutsedge control if applied when the nutsedge is 15 – 20 cm tall, but must be applied during warm weather. • A second application can be applied 7 – 10 days later.
Dual Magnum and Dual II Magnum Although registered in newly planted and post-transplant strawberries, as well as highbush blueberries, it is only effective for Yellow nutsedge control when used as a pre-plant incorporated treatment, not at the pre-emergent application timing. It provides some reduction in Yellow nutsedge development.
Sandea for Highbush Blueberries, Blackberry, Loganberry, Red and Black Raspberry • Highbush blueberry plants must be established for at least 4 years. • For all of the registered berry crops, apply when nutsedge is in the 3 – 5 leaf stage. • A second application can be applied with a minimum 45 days between applications.
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• Can be very effective in reducing Yellow nutsedge, and in the following year, depending on rate, weather and density of nutsedge infestation. • Caution: the time interval between treatment and planting strawberries is 36 months.
Sinbar for Highbush Blueberries, Raspberries and Strawberries • Only provides partial control. • Best results are obtained when the application is made shortly before, or just after, weed growth begins. • Moisture is necessary to activate the herbicide.
Glyphosate (Various Brands) – Check Individual Labels • Can be used as a directed spray (i.e. spot treatment application) or as a wiper application, depending on timing and crop. • Repeat applications can be made. • Pre-cropping glyphosate has a wide label for most crops. • Nutsedge needs to be actively growing (5 – 15 cm tall) at the time of application.
Casoron – Does Work But Has Limitations • Requires a high rate, so is expensive and treated land cannot be used for at least a year. • Use only for mineral soil. • Residual herbicide reduces immediate future crop choices.
Alternate Crop Herbicide Options if Growing Beans, Potatoes or Turnips • Eptam is effective on reducing Yellow nutsedge in mineral soils only. • All weed growth and crop stubble must be thoroughly worked into the soil prior to treatment. • Eptam must be thoroughly incorporated into the soil. • For heavy infestations, need to use the higher rates of 7 to 8.5 L/ha
Yellow Nutsedge Avoidance, Elimination, Suppression and Control (?) • Ensure potted plants are clear of any nutsedge contamination. • Don’t move machines from infested fields to clean fields without thorough cleaning. • Survey early and dig out (ensure tubers are removed); may need to dig 0.75 m deep. • Requires integrated weed management – one shot weed control will not work. • Nutsedge has poor shade tolerance: rotate to crop with dense canopy. Alfalfa and other forages are better at competing with nutsedge for light. • Use suppressive herbicides: e.g. Basagran, Dual Magnum, Dual II Magnum, Sandea, glyphosate. • Early application of herbicides is important before tubers are produced. • Systemic herbicides such as glyphosate will not kill the tubers as herbicides are not translocated to the tubers – only into the plant and the rhizomes (therefore timing is important). • Established nutsedge infestations can last for years: one plant can produce up to 7,000 tubers and spread 1 m per year (refer to the note in the Basagran trial). • Pigs will eat nutsedge tubers and can “dig” them out of the soil and have been used as a method for reducing Yellow nutsedge in a field.
Yellow Nutsedge as a Food Crop Yellow nutsedge, is edible and has a sweet almond flavour. It is sold as a food product in some countries such as southern Europe, western Asia and much of Africa. The tuber contains 12 – 30% sucrose, 25 – 30% starch and 30% oil. They are eaten raw or cooked, ground into flour,
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crushed to make a cold drink or roasted and ground into a coffee substitute. Yellow nutsedge has also been used as in turkey and pig feed.
Photographs from the Basagran + Assist Oil Trial
Untreated plot in Basagran + Assist Oil Trial – Yellow Nutsedge has spread throughout field in the three years of the trial
Basagran 1.75 kg/ha + Assist Oil Treatment 2/ha – applied when nutsedge is 15 – 20 cm tall and repeated 7 – 10 days later. Effective when applied during warm weather.
Horticulture Growers' Short Course 107 Blueberries
Evaluating New Pesticides for Insect Control in Blueberries and Raspberries
Carolyn Teasdale E.S. Cropconsult Ltd., Surrey BC [email protected]
Spray trials were carried out in Fraser Valley berry fields to test the efficacy of new pesticides against aphids on blueberries, clay coloured weevils on blueberries, and black vine weevils on raspberries. All treatments were applied with a carbon dioxide backpack sprayer to commercial fields with natural pest infestations.
Aphids on Blueberries
Blueberry growers currently rely on post-bloom insecticide applications for aphid control to reduce the spread of blueberry scorch virus. Admire (imidacloprid) has been the industry standard for aphid control the past number of years, but rotation with insecticides from different chemical groups is necessary to delay development of aphid resistance. New products that have recently been registered for aphid control on blueberries include Exirel (cyantranipirole) and Movento (spirotetramat), although grower experience with these products is limited. Closer (sulfoxaflor) is registered in Canada for control of aphids on vegetables and tree fruits, but is not yet registered on blueberries.
A field trial was carried out in a young, non-bearing blueberry field to test the efficacy of aphicides in the post-bloom period. Field plots were treated with Closer, Exirel, Movento, Admire or water as a Control (Table 1).
Table 1. Insecticide treatments applied for post-bloom aphid control in blueberries Product Water Registered in Product Active Ingredient Rate volume volume blueberries per plot per plot Control - - - - 1 litre Closer sulfoxaflor No 200 mL/acre (48 g/L a.i./ha) 0.4 ml 1 litre Movento spirotetramat Yes 365 mL/ha (88 g/L a.i./ha) 0.73 ml 1 litre Exirel cyantraniliprole Yes 1.5 L/ha (150 g a.i./ha) 3 ml 1 litre Admire imidacloprid Yes 175 mL/ha (42 g/L a.i./ha) 0.35 ml 1 litre
Aphid and beneficial insect numbers were assessed prior to treatment and three, seven and fourteen days after treatment. Exirel, Admire and Closer-treated plots had significantly lower aphid numbers than the Control plots on all post-treatment assessment dates (Figure 1). Movento was slower-acting, and aphid numbers were similar to the Control plots three days after treatment, but had decreased significantly relative to the Control plots by seven and fourteen days after treatment.
Beneficial insect numbers were low at the beginning of the trial and decreased in all plots, including the Control plots, over time. Syrphid eggs and larvae were the predominant beneficial insects present on the shoot tips. There was no effect of treatment on the number of beneficial insects (all species combined or syrphids alone) at 3, 7 or 14 days after treatment.
Horticulture Growers' Short Course 108 Blueberries
Figure 4. Aphid numbers (mean ± S.E.) in blueberry plots prior to treatment and three, seven and fourteen days after treatment (DAT). N = 4 for each treatment. For each set of bars at each date (3 DAT, 7 DAT, 14DAT), bars with the same letters are not significantly different based on Tukey-Kramer HSD (α = 0.05).
Clay Coloured Weevils on Blueberries
Clay coloured weevils are a pest of increasing concern in blueberries, as the larvae feed on the roots, weakening bushes and facilitating entry for pathogens. Unlike other weevil species, clay coloured weevil adults become active in April, before bloom. Pesticide options are limited at this time, as neonicotinoids are toxic to bees and may affect pollination if applied in the days leading up to bloom. A new insecticide, Exirel (cyantraniliprole), was registered in 2014 for control of clay coloured and black vine weevils in blueberries. The Exirel label gives a range in application rates from 1000-1500ml/ha for control of weevils.
Field plots were marked in a Fraser Valley blueberry field (cv. ‘Duke’) with a high population of clay coloured weevils. The efficacy of Brigade (bifenthrin) and two rates of Exirel (cyantraniliprole) were tested for control of clay coloured weevils prior to bloom in mid-April (Table 2). Weevil counts were made prior to treatment and three and seven days after treatment. Weevil assessments were done at night by shaking bushes over a white sheet.
Horticulture Growers' Short Course 109 Blueberries
Table 2. Insecticide treatments applied for weevil control Registered on Registered on Product Active Ingredient Rate blueberries raspberries Control water - - 1000 ml/ha Exirel – high rate cyantraniliprole Yes No 1500 ml/ha Exirel – low rate cyantraniliprole Yes No 1.12 kg/ha Brigade bifenthrin No Yes (Capture) 1000 ml/ha
Both rates of Exirel were equally effective at reducing clay coloured weevil numbers within three days of treatment, but not at seven days after treatment (Figure 2). By seven days after treatment, only the Brigade plots had significantly fewer weevils compared to the Control plots.
Figure 2. Number (mean ± S.E.) of live clay coloured weevils in blueberry plots prior to treatment and three and seven days after treatment (DAT). N = 4 for each treatment. For each set of bars (3 DAT and 7 DAT), bars with the same letters are not significantly different based on Tukey-Kramer HSD (α = 0.05).
Weevil numbers decreased in Control plots between three and seven days after treatment, which likely affected the relative efficacy of Exirel treatments.
Black Vine Weevils on Raspberries
Black vine weevils continue to be a serious harvest contaminant in machine-harvested raspberries. Black vine weevils are typically managed with a clean-up spray prior to the first pick of raspberries. Capture (bifenthrin) was recently registered for weevil control in raspberries. However, additional products are needed for spray rotation to delay the development of resistance. Exirel is registered for weevil control in blueberries and has potential for label expansion to raspberries.
The same rates of Brigade (bifenthrin) and Exirel (cyantraniliprole) that were used in the clay coloured weevil trial (Table 2) were tested against black vine weevils in a raspberry field. Treatments were applied at night in early July. Live black vine weevil numbers were assessed prior to treatment and both live and dead weevil numbers were assessed three and seven days after treatment. The black vine weevil population was low at the beginning of this trial, and weevil numbers decreased in all plots over the
Horticulture Growers' Short Course 110 Blueberries
course of the trial. There was no effect of insecticide treatment on the number of live or dead weevils found in the plots (Figure 3). Exirel treatments did not reduce weevil numbers compared to the Control treatment. There were fewer live weevils in the Brigade treatment than the Control treatment three days after treatment, however there were no differences seven days after treatment.
Figure 3. Number (mean ± S.E.) of live black vine weevils in raspberry plots prior to treatment and three and seven days after treatment (DAT). N = 5 for each treatment.
The efficacy of Exirel and Brigade may not have been apparent because of low weevil numbers in the field at the time of the spray. Live black vine weevil numbers decreased over time in the Control plots. Treatments may have been applied too early (before peak weevil emergence), as efficacy of cyazypyr (cyantraniliprole) and bifenthrin was observed in previous raspberry trials where treatments were applied in mid-July.
Acknowledgments
Thanks to Mark Sweeney (BCAgri) for arranging products and to our grower cooperators for providing access to the field sites. Thanks to Renee Prasad, Rajan Prasad, Heidi van Dokkumburg, Emily Carmichael, Sarah Busch, Kristine Ferris, Kelsey Patterson and Heather Meberg for field assistance with these trials. These projects were funded by the BC Blueberry Council, Raspberry Industry Development Council and Agriculture and Agri-food Canada’s AgriInnovation Program under Growing Forward 2.
Horticulture Growers' Short Course 111 Blueberries
Tissue Testing in Blueberry: What Have We Learned?
Bernadine Strik and Amanda Vance Department of Horticulture, Oregon State University, Corvallis, OR [email protected]
In this brief report, we are only covering recent work on tissue testing. For more information on soil testing and fertilization programs, please refer to the nutrient management guide available online at Oregon State University (https://catalog.extension.oregonstate.edu/): Nutrient Management for Blueberries in Oregon, EM 8918. A revision of this guide is planned, so stay tuned.
We conducted a two-year study at two blueberry sites, a conventionally managed commercial farm and a certified organic research trial. Plants were of similar age (mature) and were similarly managed with regard to pest, pruning, and irrigation management. Organic fertilizers were used at the organic site (predominantly fish and soy bean meal) and inorganic fertilizers at the conventional site. The total rate of nitrogen (N) used was similar among sites and years, except the N rate was increased from 2013 to 2014 at the conventional site. Yield at both sites would be considered “typical” to “high” for this region.
The cultivars studied at both sites (‘Duke’, ‘Bluecrop’, ‘Draper’, ‘Legacy’, ‘Liberty’ and ‘Aurora’) were selected to represent a range in fruiting or harvest season. Leaf tissue samples for nutrient testing were collected approximately every two weeks from April 23 to October 7 in 2013, and April 21 to October 6 in 2014, for a total of 13 samples per year.
Leaf tissue analysis provides information on the nutrient content of the plant. Sometimes, even when the soil nutrient content is adequate, the plant is not able to take up the nutrients required (e.g., when soil pH is incorrect; in dry or waterlogged soils; during cool weather; and when there is too much or insufficient irrigation). Tissue standards have been developed using results from research experiments and estimated from large databases that relate tissue nutrient levels to good yielding fields for each crop (OSU). The present standards (Table 1) were developed using ‘Bluecrop’ and the recommended sample time is late July to early August. Prior to our study, there had not been a study done to see if cultivars should differ in recommended sampling time or in tissue standards.
In all berry crops, leaf tissue nutrient concentration changes throughout the season. We confirmed this in our study (Figure 1). Also, despite very different management practices (organic vs. conventional), the leaf nutrient levels were quite similar between the two sites. While we did measure differences among cultivars for many nutrients, the best time to sample for leaf nutrient analysis was still the late July to early August period for all cultivars (e.g., Figure 2, calcium).
The recommended time of sampling leaves for tissue analysis is related to a period of time when the leaf nutrient concentration is most stable in late July-early August. This sampling time has been used successfully in other production regions in the Pacific Northwest. However, we do suggest looking at leaf samples from your particular region to assess whether slight modifications to this sampling time are needed.
Horticulture Growers' Short Course 112 Blueberries
Figure 1. Effect of sampling time on leaf tissue nutrient concentration of nitrogen (N), potassium (K), and calcium (K) at an organic and conventional site over two years (averaged over cultivars).
Figure 2. Effect of cultivar on leaf tissue calcium when sampled from late July to early August, 2014 at an organic (NWREC) and conventional (Grower) site.
Tissue nutrient levels will also change with location or age of the leaf and what type of leaf it is. In blueberry, the best leaves to sample are from shoots that are growing below the fruiting zonenot from whips. We have developed slightly revised standards for tissue levels in blueberry for our region (“revised standards”; Table 1).
Based on our new study, recommendations for sampling have not changedonly some of the tissue standards have (Table 1). When collecting leaf tissue samples: • Sample at the correct time (late July to early Aug.); published tissue standards are NOT correct if sampled at any other time of the season. Do NOT adjust sampling period based on fruiting season of the cultivarthis is not necessary and will lead to poor results. • Sample cultivars separately. Cultivars differ in leaf nutrient statusagain monitor over the years and look for changes over time.
Horticulture Growers' Short Course 113 Blueberries
• Collect the right tissuemost recent, fully expanded leaves on shoots below the fruiting zone in blueberry. • Do not wash leaves, as soaking leaves may reduce tissue K. Note that any micronutrients in fungicide applications, foliar nutrient applications and dust on leaves can lead to “higher” than typical nutrient results (keep records). • Keep excellent records on cultivars and blocks sampled, time of year sampled, and any associated yield or fruiting season information. It will be important to look for trends over time. • Tissue analysis and observations of plant growth are best used to plan for and adjust nutrient management programs for the following year. • Do not use just the tissue N concentration to adjust N fertilizer programs. Use recommended fertilizer application rates as a starting point, and then adjust programs based on observations of tissue N and plant growth. • Be aware that tissue nutrient concentrations above or below the recommended levels (Table 1) may indicate a soil problem (e.g., high tissue Mn may mean soil pH is too low). • If you are seeing problem plants at any time of the year, collect leaves from affected and “normal” looking plants and compare tissue analysis results for clues as to the cause.
If tissue testing indicates a nutrient is deficient, fertilization with this nutrient may be required. Be cautious when applying boron, especially as a granular productover-application can lead to boron toxicity.
Table 1. Recommended leaf tissue sufficiency levels for blueberry when sampled in late-July to early August.
Nutrient Northern Highbush Northern Highbush Current standards Revised standards Nitrogen (%N) 1.76 to 2 1.76 to 2.0 Phosphorus (%P) 0.11 to 0.4 0.10 to 0.20 Potassium (%K) 0.41 to 0.7 0.40 to 0.65 Calcium (%Ca) 0.41 to 0.8 0.45 to 0.85 Magnesium (%Mg) 0.13 to 0.25 0.13 to 0.25 Sulfur (%S) 0.11 to 0.16 0.11 to 0.16 Manganese (ppm Mn) 31 to 350 31 to 350 Boron (ppm B) 30 to 80 30 to 80 Iron (ppm Fe) 60 to 200 60 to 200 Zinc (ppm Zn) 8 to 30 8 to 30 Copper (ppm Cu) 5 to 15 3 to 10 Aluminum (Al) na 40 to 160
Note the proposed revised tissue standards in the second column are based on our recent research (Strik and Vance, 2015)
Acknowledgements
We appreciate the funding from the Washington Blueberry Commission for this study and the great contributions of our grower collaborator, PanAmerican Berry Growers, Salem, Oregon.
Horticulture Growers' Short Course 114 Blueberries
What Causes Green Fruit Drop and Can We Prevent It?
Eric Gerbrandt University of the Fraser Valley, Abbotsford, BC [email protected]
Introduction
‘Draper’ is a relatively new variety of highbush blueberry with some attractive features that have motivated growers to plant a considerable number of acres in BC and northwestern Washington. These attractive features include its large, firm fruit that ripen between ‘Duke’ and ‘Bluecrop’, loose clusters that can be harvested by machine or by hand and a strong waxy cuticle and excellent storability. With the good comes the bad as many growers have wrestled with production challenges, including blight and canker susceptibility, a squat growth habit and problematic pollination. Foremost in this list of challenges is a tendency to seemingly spontaneously drop a large amount of its developing green fruit, just prior to ripening (Figure 1). This physiological condition is unique to ‘Draper’ in BC and northwestern Washington, not being seen in Oregon or other production regions. Not being previously described in the scientific literature, it has recently become clear that this is an issue of maladaptation to local climatic conditions.
Green fruit drop (GFD) in ‘Draper’ is not the same condition as inadequate pollination, which results in dropping of red, disk-shaped fruit that have no seeds, or the blueberry fruit drop virus that affects entire bushes rather than fields. Upon inspection, partially developed fruit that have dropped from the bush are brown and decomposing on the inside (Figure 2) despite the presence of developing seeds, varying in severity across fields and seasons. In some fields, there is virtually no fruit dropped and in others an estimated 40 percent drops, depending on the season. No soil type, management system or production region can be exclusively linked to the appearance of this condition, but it has been noted that there is an association with a high degree of plant vigour and it is often preceded by climatic conditions that result in a period of low levels of transpiration (i.e., low temperatures, high humidity and/or cloud cover). From observations of the internal browning of fruit, a calcium deficiency was proposed by several industry experts as a potential cause for this condition because of its similarity to calcium deficiencies in other crops (e.g., blossom end rot in tomato and bitter pit in apple). To determine whether calcium applications can be used to correct the disorder, two preliminary field trials were conducted at a single farm location in Abbotsford, BC in 2014.
Materials and Methods
For each experiment, small, five-plant plots with four replications in a completely randomized block design were used to compare several calcium products over a range of nitrogen treatments to evaluate an interaction with plant vigour. In the first experiment, the plants were fertilized in the spring with chicken manure and then a no-calcium control was compared with the label rates for a calcium chloride product (8,300 ppm), a calcium carbonate product (400 ppm) and a calcium thiosulphate product (450 ppm) as well as an unreplicated observational plot of a calcium nitrate product (108 ppm). Foliar applications were made via back-pack sprayer on five consecutive weeks from the end of bloom to the star of GFD (May 20 to June 17). Note how different the concentrations are for these manufacturer recommended rates.
The second experiment compared the same calcium products, but in a row without manure and with various rates of nitrogen fertilization. Ammonium sulphate was applied at a rate of 0, 50, 100 and 150 lbs of nitrogen per acre with each calcium treatment being replicated for the lowest and highest nitrogen rate
Horticulture Growers' Short Course 115 Blueberries
and only the control (no-calcium) treatment for the two intermediate nitrogen rates. After fruit drop occurred between late June and early July, counts of the number of berries dropped in each plot and the estimated yield remaining on the bushes was used to determine the percent fruit dropped for each treatment.
Results
In the row with manure, the plants that received the control treatment dropped approximate 16 percent of their fruit. The percent fruit dropped was not significantly reduced by the calcium thiosulphate product, but it was reduced by approximately a third by the calcium carbonate product and by a half by the calcium chloride product. In the row without manure, the plants that received the control treatment dropped approximately 13 percent of their fruit across the range of nitrogen rates. The percent fruit dropped was most dramatically reduced by the calcium chloride product under high and low nitrogen rates while being more moderately reduced by the calcium carbonate and thiosulphate products. The reduction in drop in response to calcium treatments was more dramatic at the low nitrogen rate, providing confirmation that this physiological condition is associated with plant vigour. As well, the percent dropped from each bush was negatively correlated with the estimated yield, which indicates that the treatments that reduced drop were also effective in increasing yield. This is important because it shows that the calcium treatments were actually corrective rather than causing the earlier abortion of flowers/fruit due to phytotoxicity or changing the balance of reproductive to vegetative growth. At the same time, the calcium chloride treatment, which was applied at a much higher than the others and contains the chlorine to which blueberry plants are sensitive, did result in a considerable amount of leaf burning (Figure 3).
Conclusions
From this preliminary research, it can be stated with considerable confidence that calcium deficiency is the cause of GFD. Availability of calcium in the soil likely does not matter since the plant is primarily accessing calcium from its internal tissues during the time when calcium is being loaded into the developing fruit. The time of peak calcium concentration in the fruit is just after fruit set and so getting calcium into these tissues at an early stage will likely be important to correcting the deficiency. Foliar applications do correct the condition, despite the fact that calcium movement within the plant is limited in such a way that there is unlikely to be significant transport of calcium from leaves to fruit. Pending tissue analyses, this is likely to be explained by transport of calcium directly across the surface of the developing fruit.
The observation that GFD is worse in fields with high vigour, and the experimental results that show a more dramatic reduction of drop in response to calcium under lower nitrogen treatments, point to a logical physiological explanation: competition between shoots and developing fruit during the early season results in a calcium deficiency in ‘Draper’ in southern BC and northwestern Washington. At higher rates of nitrogen the plant has greater vegetative vigour, which leads to greater sink strength in the shoots in comparison with the developing fruit and a subsequent calcium deficiency in the latter. This explanation of maladaptation is further supported by research in Oregon (Dr. Bernadine Strik, personal communication) that recently demonstrated the abnormally large difference between leaf and fruit calcium in ‘Draper’ in comparison with other varieties, especially under high nitrogen conditions.
Recommendations
Which products correct GFD, as well as the appropriate rate, date and number of applications, have yet to be determined by research. Research to provide a more thorough description of how and why GFD occurs is also underway. In the meantime, it is recommended that growers work with their consultant to
Horticulture Growers' Short Course 116 Blueberries
use calcium applications to correct the condition. Calcium chloride, the cheapest product trialed, was also the most effective. This is likely due to the fact that it was applied at the highest rate but also because of the relative ease of calcium uptake in this form. It is recommended that growers and consultants use caution in applying any product as, depending on the rate and product, phytotoxicity is potentially more damaging to the crop than the condition which their use is intended to correct. At this time, the only positive recommendation that can be made is to judiciously apply a product that will deal with what, by all appearances, is a calcium deficiency. Correcting this deficiency via soil application is unlikely to work, but foliar application as the plant approaches full flowering has been shown to be effective.
Figure 5. ‘Draper’ fruit on the ground as they drop from the bush during the onset of green fruit drop.
Figure 2. Internal browning of otherwise normally developing ‘Draper’ fruit with adequate pollination.
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Figure 3. Symptoms of phytotoxicity in response to the calcium chloride applications, which were highly effective in correcting the green fruit drop disorder.
Acknowledgments
Participating growers: Mark Sweeney (BC Ministry of Agriculture); Tom Baumann and Zach Fleming (Expert Agriculture Team Ltd.); Karina Sakalauskas and Michael Dossett (BC Blueberry Council); Lisa DeVetter (Washington State University); and Bernadine Strik (Oregon State University).
Funding Provided By:
Horticulture Growers' Short Course 118 Blueberries
From Planting to Maturity: Which Cultivars Rise to the Top?
Bernadine Strik and Amanda Vance Department of Horticulture, Oregon State University, Corvallis, OR [email protected]
We have evaluated 10 cultivars (‘Duke’, ‘Liberty’, ‘Bluecrop’, ‘Bluejay’, ‘Legacy’, ‘Draper’, ‘Reka’, ‘Aurora’, ‘Ozarkblue’, ‘Bluegold’) from the first (2007) through seventh (2013) growing seasons in a certified organic planting at OSU’s North Willamette Research and Extension Center, Aurora, Oregon. Plant spacing was 0.76 m x 3 m. The trial was pruned annually by B. Strik (for consistency) and various plant developmental and yield data were collected from the second through seventh fruiting seasons. Some of the findings from this study, coupled with observations in grower fields, are presented here. We encourage growers to keep their own records to see how cultivars vary from year to year and to assess any environmental effects.
The first step in getting good yield is to have good fruit bud set – this is a measurement of the proportion of buds on a good (15 to 30 cm-long) lateral that are fruit buds (e.g., the number of fruit buds/total number of buds x 100). Over our six-year study (second through seventh fruiting seasons), percent fruit bud set varied by year and by cultivar. The lowest fruit bud set (as low as 22%) was found in ‘Bluecrop’. Bud set ranged from 40% to 57% in ‘Duke’, 30% to 54% in ‘Reka’, and 38% to 54% in ‘Liberty’. Bud set is affected by the length of time in autumn that weather is ideal for flower bud development, and by cultural factors. For example, excessive or late fertilization with nitrogen will reduce fruit bud set.
The number of flowers within each fruit bud was not affected by year, but was strongly affected by cultivar. The fewest flowers per bud (flowers per cluster) were found in ‘Duke’ (7.1) and the highest in ‘Ozarkblue’ (10.2). ‘Bluecrop’ averaged 8.9 flowers/bud and ‘Reka’ 8.5 over the 6-year study.
Percent fruit set (how many flowers become berries) was not affected by year and there was little cultivar effect. Percent fruit set averaged 93%, but would be expected to be lower in a region with cool and/or rainy weather during bloom. The number of bee visitations per flower affects how many seeds are set per fruit. We have found that some cultivars (e.g., ‘Bluecrop’ and ‘Draper’) do not form a berry when there are no seeds. However, ‘Duke’, ‘Liberty’ and ‘Aurora’ do produce berries that contain no seedsthese fruit will, however, be small, weighing less than 1.0 gram. Seed number per berry was very strongly related to berry weight (size) in ‘Duke’, ‘Liberty’, ‘Bluecrop’, and ‘Legacy’, but was less so in ‘Draper’ and ‘Aurora’.
Berry weight was affected by planting age and cultivar. Of course cultural practices, particularly pruning can have a big effect on berry size.
The firmness of ripe fruit was greatest in ‘Draper’. The next firmest was ‘Duke’. ‘Legacy’ and ‘Bluegold’ ranked similarly and were just below ‘Duke’. ‘Aurora’ and ‘Ozarkblue’ were similar in firmness and were more firm than ‘Reka’, ‘Bluecrop’, ‘Bluejay’ and ‘Liberty’ which were in the least firm group. In addition to varying by cultivar, firmness was also affected by planting age and cultural practice. Weather can also affect firmness. For example, ‘Liberty’ has been observed to have a drop in firmness when harvesting after a hot day.
We found relatively little difference among cultivars in percent soluble solids (ºBrix) which ranged from 12 to 15%, depending on cultivar and year. However, there were relatively large differences in the total acidity of the fruit. Cultivars were quite consistent in the sugar to acid ratio over harvest years.
Horticulture Growers' Short Course 119 Blueberries
Yield increased consistently from the second through seventh growing seasons in all cultivars, except ‘Bluegold’ which had Blueberry Shock Virus at a young planting age that limited re-growth. The highest yielding cultivar was ‘Legacy’ (18 tons/acre in year 7). The yield for some other cultivars grown with weed mat in year 7 was: ‘Duke’ (7 tons/acre); ‘Liberty’ (10 tons/acre); and ‘Bluecrop’ and ‘Reka’ (11 tons/acre) – note these yields are extrapolated from four hand-harvested 18-ft plots.
While ‘Duke’ is a great early-season, fresh market cultivar, it is very sensitive to soil pH being outside the ideal range of 4.5–5.5 (bad growth and leaf nutrient deficiency symptoms when pH drops too low or too high), poor soil drainage (is sensitive to phytophthora root rot), and excess fertilization (high salts).
‘Legacy’ is now a very popular cultivar in Oregon’s Willamette Valley for its high yield, long fruiting season and good fruit quality. However, this cultivar is not sufficiently cold hardy to grow in colder regions, including B.C. The fruit buds on ‘Legacy’ are very sensitive to early cold spells in autumn and have relatively low hardiness in mid-winter. They start growing early in the late-winter or spring, making them sensitive to late-winter/spring frosts. We do not recommend this cultivar for northern Washington or the Fraser Valley for these reasons.
‘Draper’, ‘Liberty’ and ‘Aurora’ are more expensive to prune than ‘Duke’ (20% to 30% longer). In addition to ‘Liberty’ fruit softening in the heat, this cultivar also has a big “top” relative to a smaller root system. This makes the plant very sensitive to wind breakage (use a trellis at a young age) and to insufficient irrigation or drought. This cultivar also has some issues with “little berry” on what looked like good pruning wood the previous winter, and cane disease.
‘Draper’ has a fruit drop problem in northern Washington and B.C., which may be related to low fruit calcium (research is underway). ‘Aurora’ fruit are quite sensitive to sun burn and should be left to “hang” (ripen very well) in order to be later and have better quality than ‘Elliott’this is not typically possible in more northern growing regions due to the lateness of this cultivar. Finally, ‘Reka’ is very productive in most regions and must be pruned hard/well to produce high-quality fruitplants that are not pruned well will produce fruit with a ‘red back’.
Growers are encouraged to choose a new cultivar carefully, considering adaptation to the climate and choosing the best cultivar within the desired fruiting season. Be aware of the limiting factors to yield (keep records) and manage for the weakest link to maximize growth and production.
We appreciate the funding support from the Oregon Blueberry Commission.
Horticulture Growers' Short Course 120 Hazelnuts
New Hazelnut Cultivars and a Trial to Evaluate Them in BC
Thom O'Dell and Haley Argen Nature Tech Nursery, Langley, BC [email protected]
Background of Hazelnuts
BC's Fraser Valley has been home to Canada's hazelnut industry since at least the 1940's. The recent arrival of a devastating disease is wreaking havoc in orchards in Chilliwack, Agassiz and elsewhere, but a solution can be found in new cultivars from the breeding program in Oregon. At Oregon State University, about 4000 seedlings per year are grown from controlled crosses of superior parents in a classic breeding program; after 16 or more years of careful evaluation of the most promising seedlings, a few are released as named cultivars. A trial is underway in southwestern BC to demonstrate suitability to local conditions and learn about pollination timing and yields of six blight resistant cultivars released from the OSU breeding program. But why is this focus on hazelnuts important?
Estimates vary, but there were at peak about 1200 acres of hazelnuts in BC, mostly in the lower mainland with an annual harvest worth $1.3 million. These numbers are shrinking as diseased orchards decline and die, or are removed. Most of the nuts currently produced go to the United States (and many thence to China). Some are sold locally, but Canada imports over 90% of its hazelnut supply from the US and Turkey. The US is also a net importer of hazelnuts and Canada’s largest trading partner; this means there exists good long-term market stability. BC’s hazelnut industry is in decline mostly because of EFB, and in part because many current orchardists are at or near retirement and so aren’t sure that replanting their diseased orchard makes sense for them. However, we are working with others who see great promise and value in hazelnuts as a crop, and who strongly believe that a revitalization of the hazelnut industry in BC is both possible and important. They see it as a profitable crop looking ahead, since demand both globally and in our region far outstrips supply. We are lucky to have two commercial processors already in the Fraser Valley who supply an important service for the supply chain, but they need more growers and orchards to supply raw nuts.
There are many reasons that hazelnuts should be considered by farmers in BC. They are a tasty and healthful source of protein and oil with endless possibilities for adding value. Hazelnuts are sold in-shell or as kernels (raw or roasted), in candy, as a protein powder, as nut butters or chocolaty spreads, as syrups, in snack foods and breakfast cereals, and new products are being developed all the time. The trees are attractive and long-lived, can provide shade to help cool buildings, and many current orchardists tell us they love tending their trees, looking over and walking in their orchards. Hazelnuts fit very well in permaculture, agroforesty and silvipasture systems. Compared to many other crops, inputs in terms of supplies and labour are low, so part-time and small lot farmers can easily manage their orchards and qualify for agricultural tax rates on their land. As nut trees go, hazelnuts are very precocious, with commercial harvests being possible just 5 years after planting and full yields being seen between 10 to 12 years. Where profitability in the early years is important, farmers can increase yields from their land by alley-cropping between the rows of trees and planting trees double-density in the rows. Looking forward, perhaps one of the most important attributes of hazelnut trees is that as a fast-growing perennial tree crop, they sequester more carbon than most crops, an offset to the high contribution to greenhouse gas emissions that is a hallmark of most agricultural production systems. Finally, they have the potential to greatly enhance local and regional food security as a low-input crop with a very high food value.
Horticulture Growers' Short Course 121 Hazelnuts
Current Situation
Eastern filbert blight (EFB) caused by the fungus Anisogramma anomala arrived in Washington State in the mid-1970's and made its way to BC by 2005. It is spread by wind and infects young shoots and branches in the spring, causing dieback of limbs. Control measures include aggressive pruning and fungicide treatment. Currently it’s affecting every commercial orchard in the lower mainland. This is despite a quarantine on importing hazelnut trees (except in disease-free tissue culture) to British Columbia from any region known to have EFB. Should the quarantine then be relaxed? Absolutely not!
EFB is native to eastern North America where there are hundreds of strains, yet the evidence is that in the Pacific Northwest there has been a single introduction of the disease. Limiting new introductions of EFB are crucial to maintaining the efficacy of hazelnut cultivars selected for resistance to the local population of EFB. Both Washington and Oregon maintain quarantines for just this reason and experts agree that BC must do the same to protect the long-term viability of the industry here as well as across the border in Oregon and Washington, and support the significant and important breeding work at OSU of which we are beneficiaries.
Over a dozen cultivars with high resistance to EFB have been released in the past decade or so from the OSU breeding program. While some are not readily available and the most recent are patent-protected (not licensed in Canada), six of them are included in the BCHGA cultivar trial. There are uncertainties and challenges facing the hazelnut industry in BC, yet there is also opportunity with new, high-yielding releases such as 'Jefferson', ‘Sacajawea’ and 'Yamhill'. But growers need to remember that it takes time to produce a quality tree and they'll have to plan ahead and work with nurseries to get the trees they want, when they want them.
Trial
Goals • To demonstrate the suitability of EFB resistant hazelnut cultivars to the Fraser Valley. • To compare performance of three EFB resistant hazelnut production cultivars and three pollinizer varieties at six sites in southwestern BC. • To share information on cultivar performance with growers.
Approach
Trees were planted at six sites in the lower mainland/gulf islands at double density (9'x18' – 10'x20'); about 500 trees were planted at each site in total between 2011 and 2013. Some sites needed clearing of existing orchards at significant expense. Each site is managed by the owner in terms of fertility, water, weed control, pruning, etc. Site locations are mostly in the Agassiz/Chilliwack area but one is on Hornby Island.
‘Jefferson’, ‘Sacajawea’, ‘Yamhill’ are the main crop cultivars, with ‘Eta’, ‘Gamma’, and ‘Theta’ as the main pollinizers at 15% of total.
Variables being monitored include: growth and health of trees, flowers timing of: catkins (tassels) and female (pistillate) flowers, nut yield, nut quality, and time of harvest.
Current status • Trees planted in 2011 are up to 65mm in diameter. • Nuts have been produced from 2011 and 2013 plantings in small numbers. • No symptoms of EFB have been observed.
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Preliminary results
2014 was the first year of regular flower observations and nut quality evaluations. Since these trees are still young and not all yet flower or produce nuts, these results are based on small sample sizes and must be considered preliminary.
Pollination
In 2014 all cultivars but Sacajawea had some flowering (including catkins), though not all produced pollen; Sacajawea was not seen flowering. Both Yamhill and Gamma produced catkins but neither shed pollen, probably because of the freezing cold, dry conditions in January. The relative order of flowering was similar to that reported from Oregon, but delayed by two to three weeks.
Next Steps
We will conduct our second season of flower monitoring this winter (January to April 2015) and begin gathering some yield data in fall 2015. We will continue to share updates with the hazelnut grower community.
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Hazelnut trees in the nursery.
Young orchard of ‘Jefferson’ hazelnut (planted 6/2011; photo 7/2014).
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Some value-added products from hazelnuts. . We are grateful for the assistance of the following in support of this project. • Investment Agriculture Foundation; • BC Hazelnut Growers Association; • Participating farmers: Peter Andres, Walter Esau, Pentti Hanninen, Helmut Hooge, Charlotte Spencer, Neal teBrinke ; • LMHIA; • Mark Sweeney, Fruit and Berry Specialist, Ag. BC; • Dr. Shawn Mehlenbacher, Rebecca McCluskey & David Smith, Oregon State University.
References
Toma, D. 2015. BC Hazelnut Industry Development Plan.
Capik, J. and T. Molnar. 2012. Assessment of Host (Corylus sp.) Resistance to Eastern Filbert Blight in New Jersey. J. AMER. SOC. HORT. SCI. 137(3):157–172.
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A Preliminary Report on Hazelnut Enterprise Budget in British Columbia
Wallapak Polasub Institute for Sustainable Food Systems, Kwantlen Polytechnic University, Richmond, BC [email protected]
The development of hazelnut enterprise budget for British Columbia is part of the “Sustainable Agriculture Enterprise Budget Series” project funded by the enviroFund 2013. The project aimed to create enterprise budgets for common vegetable and livestock enterprises in southwestern British Columbia, specifically for small-scale farm operation. The hazelnut budget has not yet been completed, as more information from growers is still needed. This presentation offers information on the definition and components of an enterprise budget and what growers may expect in term of costs and returns from keeping a hazelnut orchard.
A hazelnut enterprise budget simply projects costs and returns of growing hazelnuts over a period of time. In order to complete the budget, researchers need information from current growers who keep detailed records of their orchard operation, such as labour and machinery hours, types of machinery and equipment, and revenue from selling the nuts. Researchers may visit individual orchards or invite hazelnut farmers to a focus group session to gather the needed information. Afterwards, the hazelnut enterprise budget is calculated based on a set of assumptions set forth by researchers (such as the rate of interest, fuel cost and tree spacing). The budget represents a typical orchard in the region and does not represent a particular orchard. Therefore, growers who have submitted their information need not worry that their orchard financial records would be publicly available to their competitors.
In a standard enterprise budget, there are four major components: fixed costs, variable costs, revenue, and net return. Fixed costs refer to the costs that do not change with the level of production in the short run. Fixed costs are often associated with longer-term investment such as buying machinery, building and land. For example, the production of hazelnuts may increase without purchasing more land. On the other hand, variable costs refer to costs that change with the level of production. For example, in order to produce more nuts, farmers may choose to increase the tree spacing or increase tree maintenance efforts. Revenue is the income generated from selling the nuts. Finally, the net return is calculated by subtracting the total cost from the total revenue.
To establish a small-scale hazelnut orchard (assuming that the land is owned by the farmer), a farmer may expect to invest at least $30,000 in fixed costs such as a tractor, rototiller, flail mower, trailer, tote boxes, irrigation system, taxes and insurances. Depending on the size of the orchard, growers may choose to either buy or rent the machinery or even to outsource the task. For example, a small orchard owner may choose to hire someone else to harvest the nuts instead of purchasing a harvester. For the purpose of the enterprise budget, the initial investment (fixed costs) has to be recalculated into an annual basis. From our example, the $30,000 fixed cost in the first year can be recalculated into a fixed cost of about $600 per acre annually (under the assumptions given by researchers).
Next, we take a look at the total variable costs and what growers may expect to pay each year to maintain a mature orchard. The tasks categorized as variable costs include tree planting and maintenance, pruning, sucker control, flailing, leveling, pest and nutrition management and harvesting. Note that labour and fuel costs are embedded within each task. Therefore, it is necessary that growers keep detailed records of their operations so that a reliable enterprise budget can be established. For example, it may take 2 hours to prune one acre of a hazelnut orchard. If a worker is hired at the rate of $15 per hour then the pruning cost per acre is $30. Our preliminary calculation suggests that the total variable cost is about $700 per acre annually.
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To calculate the total revenue (or gross revenue), we need to know the total yield and the selling price(s). At the moment, we do not have the yield data for the new Eastern Filbert Blight resistant hazelnut varieties. Instead, we refer to the average yield data from five orchards in Oregon. The average yield of the ‘Jefferson’ variety is 2,770 pounds per acre. The selling price varies each year, depending on the supply and demand and other outside factors (such as a late hazelnut season in Turkey). For example, in 2013, the price was about $1.25/lb to $1.50/lb, while in 2014 the price was a record high of $2/lb. Therefore, the total revenue is expected to vary from $3,400 to $5,500 per acre.
At this time, we cannot present a complete picture of the costs and returns of growing hazelnuts. We have not received enough information to establish a robust hazelnut enterprise budget. We hope that BC hazelnut growers would be interested in collaborating with us. Together we can revive the hazelnut industry and produce a complete hazelnut enterprise budget for the BC region!
For more information on the Institute for Sustainable Food Systems’ enterprise budget series, please visit our website at: http://www.kpu.ca/isfs/enterprise-budgets
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BC Hazelnut Industry Development Plan
Darrell Toma Toma & Bouma Management Consultants, Edmonton, AB [email protected]
British Columbia Hazelnut Industry Overview
The project objective was to assess the current industry situation in view of world markets, trends and the BC grower interests which were reviewed in a survey. The BC hazelnut industry has existed in the province since the 1930s and has expanded to production areas in the Fraser Valley, the Okanagan and several islands. Currently the industry has over 40 growers with about 650 acres of production and a gross farm value in the order of more than $1.3 million annually (BCHGA). The industry also has several processors and it is a very export-oriented industry with most product sold to the USA (Oregon).
Survey Findings
A total of 23 people responded to the survey, which is 37% of the people in the survey list from the BCHGA. From the survey and industry feedback, a tree replanting program and access to new disease resistant trees are very important to their decision-making. A number of current growers are hesitant to reinvest given a tree takes 5 years to grow (no income) and they are nearing retirement. The economics of a tree are such that it provides a long-term income stream with low inputs and management, but the first 8 years may see minimal production and revenues. Survey results are noted on page 11. The top concerns (from the survey) include: • Hazelnut tree replanting support program (just as is done for apples, or other crops); • The main problems are Eastern Filbert Blight in the orchards, high changeover costs, no clear replacement plan, a lack of awareness and no provincial support; • Technical, agronomy, processing and marketing advice is lacking for BC hazelnuts; • New growers are interested to start, and most growers would encourage people to enter the hazelnut industry, but no one is encouraging new entrants; • No industry support (public) is seen to exist by most people; • More industry awareness, promotion and a development plan for growth is needed. World Hazelnut Market is Growing
The global demand for hazelnuts is growing with Turkey, Spain, Italy and the USA (Oregon) as the main suppliers. Australia, New Zealand, Chile, several USA states and Ontario and PEI are in process of planting new acreage. In North America, Oregon and BC are the main supply regions. Global production is in the order of 800,000 tonnes annually and due to weather variation, supplies vary. A role exists for regional economic development agencies (CEPCO, Fraser Valley Regional District) and allied government trade representatives for new foreign direct investment (FDI) opportunities into this industry.
Climate and Experience are Unique BC Production Advantages
Hazelnut trees require a specific warmer climate (minimum and maximum temperature, growing days, precipitation) in which to grow and BC sites are very well suited to these trees. Globally few regions have this unique capacity for growing these orchards. From some economic data, net returns to BC growers are in the order of $2,100 to $2,300/ acre and with farm status, an additional tax savings can be obtained annually (is site specific). With improved agronomy and higher yielding new trees, returns can be improved substantially.
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BC Hazelnut Industry Development Plan
The BC hazelnut industry is facing the tree disease (EFB- Eastern Filbert Blight) and it is clear the industry needs to follow a development / transition plan. The plan involves six main actions: • Rebuild the BC supply base of hazelnut orchards with EFB resistant trees; • Build hazelnut grower awareness and promote the industry; • Understand world markets and how to access these markets; • Know and communicate BC hazelnut profitability and production economics; • Work with current processors for industry growth; • Enhance the BC Hazelnut Growers Association.
Potential costs to implement the plan are summarized below. It is noted that the industry is a perennial crop based opportunity and thus once re-established can operate on its own with minimal public sector support. The plan below targets a larger supply base of 1.000 acres up from the current 650 acres. This higher target is possible and will provide more opportunity for processors and BC to gain market share of the expanding markets. BC has a unique strength of climate and prior hazelnut production experience which others nations, states and provinces desire. Two levels of growers can be viewed: small-scale (1 to 3 acres) and commercial-scale farms (10 to 100 acres).
A critical foundation to the industry is strengthening the BCHGA and the technical and agronomy aspects for new and existing growers. Current yields of hazelnut production are lower than potential levels (as noted in the literature). This part of the plan is $105,000 annually.
Another foundational part of the plan is to implement a tree replanting program for qualified growers and use of disease resistant hazelnut trees. Currently an embargo on tree plantings is in place and a short-term supply gap exists. Cost-sharing is a potential program approach to consider, as are tree volume discounts and related replanting costs. This program needs to be discussed with the stakeholders as the time to re- establish may be long.
Table. Development Plan Implementation Costs
Item Cost Comments Replant/ Planting Program $1.2 million ($12/ Target of 1,000 acres; only for qualified (one time) tree x 100 trees/ acre) EFB resistant trees BCHGA Strengthening $60,000 Website, association support and (annual) agronomy- extension Variety Adaptation Research $25,000 To adapt varieties to BC sites – research (2.5% of revenues) partners (annual) Awareness/ Promotion $20,000 To attract in new growers; FDI (annual) investors- economic development agencies BC Ag/ University of Fraser Staff and research To stimulate hazelnut developments- in Valley/ qualified service projects tree supply, marketing and processing providers Total $1.2 million one time $105,000 annual
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In discussing and assessing the plan for growth it is clear that BC has a unique opportunity to re-establish its prominence in hazelnuts, create many rural-based jobs and income and provide the basis for a sustainable agriculture industry. These high value and nutritious food products fit well with the provincial vision for growth in a world with rising incomes seeking healthy food products. A discussion on the policy gap and actions are needed.
The BC hazelnut rural economic opportunity should not be lost given the export market demands for these healthy food products.
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Keeping the Door Shut on Invasive Vegetable Pests
Tracy Hueppelsheuser British Columbia Ministry of Agriculture, Abbotsford, BC [email protected]
Pests for discussion include: swede midge, brown marmorated stink bug, bagrada bug, Colorado potato beetle, Japanese beetle, and European corn borer. Information I will be sharing has come from various sources, and for further information, see these references: BC Ministry of Agriculture website, Canadian Food Inspection Agency, Ontario Ministry of Agriculture, USA Universities and governments.
Swede Midge (Contarinia nasturtii)
Quote from Hannah Fraser, Ontario Ministry of Agriculture, Entomology: “You don’t want this pest…” Ontario’s swede midge website: http://www.omafra.gov.on.ca/english/crops/facts/08-007.htm Swede midge is a small gall-forming fly from Europe, only 2 mm long, and very delicate. It can infest any brassicae plants (crops and weeds), and there is differing susceptibility between cultivars and species. This pest was first recorded in North America in southern Ontario in 2000. Initially, it was regulated in both the USA and Canada, and then deregulated in 2009 in both countries.
Damage and Implications: Larvae feed on new tissue in growing points. Tissue becomes swollen, distorted, twisted, crinkled, and scarred, making transplants unusable. Older plants are less susceptible, but blind or multiple heads can occur. Damage can be confused with nutrient issues (low, imbalance), and varietal issues (instability).
Global distribution: Asia: Turkey, south east Asia; Europe: common and widespread; Canada: Saskatchewan, Manitoba, Ontario, Quebec, Nova Scotia, Prince Edward Island; USA: New York, Connecticut, New Jersey, Massachusetts, Vermont.
Risk of introduction: Southwestern BC is a high risk location due to climate. Highest risk for introduction is with transplants and soil. There is some risk with cropping equipment, if soil containing larvae and pupae remains. Natural spread by wind does occur. There is no risk with edible produce. Canola: No risk because there is no plant movement.
2009-2014 Survey in BC: No swede midge adults were recovered. No reports of suspicious damage. Plans are to continue to survey until 2018 (under current funding) and continued outreach to growers and the public.
Prevent Swede Midge from entering BC: http://www.agf.gov.bc.ca/cropprot/swede_midge.pdf • Use clean transplants; • Use local sources, or proven clean sources; • Field sanitation and crop rotation; • Control brassicae weeds; • Be on the look-out and report suspicious symptoms.
Brown Marmorated Stink Bug (Haylomorpha halys) (BMSB)
This insect is native to Asia. It has caused crop damage in Japan, Korea, and China in the last decade. It has been present in the eastern USA, Pennsylvania since 1996, and Portland Oregon since 2004. BMSB has spread to many states, including Washington. It is not regulated in North America. The host range is
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very broad, fruit and vegetables (<300 hosts) including: Vegetables: legumes, peppers, tomatoes, corn, soybeans, snap beans; Fruit: apples, peaches, figs, mulberries, citrus, persimmons, berries, grapes; Ornamentals; Weeds; Woody plants, trees (in eastern North America: elm, oak, locust).
BMSB Damage: Crop injury was first reported in Pennsylvania in 2008, and has gotten worse in recent years. It took more than 10 years after first detection until any crop damage was noticed. In 2011, the first report of fruit damage was to raspberries in Oregon (just outside of Portland). In 2013, first report of bugs in peppers field late in season (WA/OR border). Oregon crop consultants are still not seeing it in weekly monitoring of berry crops (2014), however, which indicates that populations are still low or nil in most commercial fields, until possibly late in the season. BMSB is considered a “Hitch-hiker”, as it moves to new areas on vehicles along transportation corridors, in non-plant shipments, packing material, boxes, and even suitcases. There is some natural spread from established areas.
Distribution in Canada: limited primarily to Ontario at this time. First confirmed in 2010 in the Hamilton port area, and in 2012, eggs were found, indicating establishment. No known crop damage yet. 2014: established in Hamilton, Burlington, London, Windsor, and St. Catharines. BMSB is expected to become a nuisance to homeowners when bugs aggregate in fall/winter first, before it establishes as an agricultural pest.
BMSB currently does not occur in British Columbia. We are watching for any detections, via some trapping and public awareness. Watch for aggregating stink bugs in fall (Sept/Oct); in/on buildings, preparing for winter. (Asian ladybeetles do this too). If you see this, please call the BC Plant Health Lab at the Ministry of Agriculture in Abbotsford. http://www.al.gov.bc.ca/cropprot/bmsb_alert.pdf
Bagrada Bug (Bagrada hilaris)
Another bug of interest, it is also called the harlequin bug or painted bug. In Arizona and southern California it is mainly a pest in cole crops, but has also been recorded on potato, maize, sorghum, cotton, capers, some legumes, and weeds. It prefers warm temperatures, the optimal is 30°C. It is native to Africa, the Middle East, and India. It is possible that it is too cold in BC for it to survive, but it may survive in greenhouses if it were introduced on planting material.
Colorado Potato Beetle (Leptinotarsa decemlineata) (CPB)
Native to North America and initially fed on wild solanum plants. It adapted to the introduced potato crops in the 1850s and moved east through cultivated crops as it became a significant pest. CPB has one generation per year. Adult beetles overwinter in soil outside of fields. In Spring (late May), adults move from field edges to find and lay eggs in hosts: potato, tomato, eggplant, pepper. Larvae feed in June and July. Adults and larvae eat foliage. Pupation occurs in Fall.
Colorado potato beetle distribution in BC: First reported in BC in 1911 at Newgate (border south of Cranbrook) (Gerber 1994, BC Ministry of Agriculture). 1994: present in Kootenay valleys, south Okanagan and Similkameen valleys. 2000s: Lillooett. It is NOT present in the Fraser Valley. If you have seen CPB in different areas from this, please let me know.
Japanese Beetle (Popilla japonica)
Established in eastern North America, but is not established in western North America. It is a quarantine pest in Canada and the USA. It feeds on a few hundred host plants. Most at risk are: Vegetables: corn, silk (adult beetles), Grass; roots, (larvae), Ornamentals: roots and foliage. Oregon is currently implementing
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an eradication program in the Portland airport area. The insect is commonly transported from eastern cities to other locations on transport planes. Courier companies and carriers take aggressive action to try to prevent movement of beetles.
How to Prevent Japanese Beetle from entering BC: Do not import plants or sod from areas where the beetle is established into British Columbia. See the CFIA website for more information.
European Corn Borer (Ostrinia nubilalis) (ECB)
This pest was introduced into Massachusetts in 1917. It is not present in BC; is a regulated pest and reportable. It is not known to be present in the western USA either. In the midwest and eastern parts of North America, ECB is a major pest of sweet corn and can cause damage in field corn. It has a surprisingly high number of hosts, totaling more than 200. It is a highly adaptable insect, evidenced by its significant impacts on potatoes in Prince Edward Island in recent years, as well as impacts in sweet peppers, peas, beans, apples, tomato, onion, and even small grains.
ECB does not occur west of the Rocky Mountains. It has 1-4 generations, depending on latitude. On the Canadian prairies, it has only one generation, and in southern Ontario, there are 2 generations. The CFIA will be surveying in 2015 in BC corn growing areas for this insect using pheromone traps.
ECB moths can be easily confused with other medium sized tan moths, such as others in the families Crambidae (sod webworm / cranberry girdler), Tortricidae (many common leafroller species), and Pyralidae (Udea profundalis). It is necessary to look for plant damage, such as ‘shot-holes’ from young larvae feeding on leaves, and eventual plant wilting and lodging from larger larvae boring into the plant stems.
How to Prevent Corn Borer from entering BC: Do not import plant or parts (corn, primarily) from areas where the borer is established into British Columbia. See the CFIA website for more information.
For all your vegetable questions, check out the BC Vegetable Production Guide located at http://productionguide.agrifoodbc.ca/
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Environmental Farm Planning: A Tool to Manage Nutrients
David Poon BC Ministry of Agriculture, Abbotsford, BC [email protected]
The objective of this presentation was to provide general information about 1) what a Nutrient Management Plan (NMP) is; 2) what to look for in the soil when “nutrient management planning”; and 3) what to look for in what’s added to soil (Manures/composts, cover crops).
Above all, nutrient management planning is an iterative process to help growers manage nutrients for optimal crop production and environmental sustainability (water and air quality). The voluntary and confidential Canada – BC Environmental Farm Plan program (www.bcefp.ca), and the associated BMP or Beneficial Management Practice program, supports the iterative process (a “plan-do-check-act” and repeat) by providing cost-share funding for the first two NMPs. However, the tools to support nutrient management planning are available regardless of whether BMP funding is used.
Whereas “plan-do-check-act” describes the process, the 4 R’s describe the aspects of nutrient management common to all farms: 1) Right Rate, 2) Right Source (e.g., woody compost vs. starter fertilizer), 3) Right Placement (e.g. surface broadcast vs. drip application), and 4) Right Time (e.g., in time for crop uptake vs. in time for runoff with next storm event). The 4 R’s are interrelated: a change in one factor affects the other factors, and a complete Nutrient Management Plan will consider the 4 R’s thoroughly. The focus herein is on the “Right Rate”.
To illustrate the basics of determining the Right Rate, we work through the example of a spring wheat field to which a farmer in Delta, B.C. is interested in applying pelleted chicken manure. Consideration is given to nitrogen (N) and phosphorus (P), since the approach to estimating P rates is similar to that of other major nutrients (e.g., potassium) and N and P are nutrients of environmental concern. The value of an NMP becomes more apparent when variables are changed: soil test results (Table 1), manure/compost selection (Table 2), and cover crop management (Table 3).
In the Baseline scenario, we make the following assumptions: • The spring wheat crop needs 90 lb N/acre1; • Pelleted chicken manure (4% N, 3.5% phosphate P2O5) is applied at 1.5 tons/acre; • 60% of the total N is available in the year of application from the chicken manure; • 85% of total P is available from all manures and composts.
Values in the tables below differ slightly from those in the presentation at the Short Course.
Table 2. Decreasing soil test phosphorus (P) from 91 ppm (Kelowna method) in ‘Baseline’ to 25 ppm (Kelowna method) in Scenario 2 increases the phosphate (P2O5) recommendation and decreases the amount of P in excess of crop requirements. Crop P2O5 recommendations are available for various crops from the Soil Test Phosphorus and Potassium Converter, Version 2 (B.C. Ministry of Agriculture, 2015). Unlike P and potassium (K), conventional soil nitrogen (N) results do not significantly affect the crop nutrient recommendations. Baseline Scenario 2: decrease soil test
1 Canadian Fertilizer Institute. 2001. Nutrient Uptake and Removal by Field Crops. https://www.cfi.ca/_documents/uploads/elibrary/d161_NU_W_01[1].pdf/
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P lb N/acre lb P O /acre lb N/acre lb P O /acre 2 5 2 5 Crop nutrient recommendation 90 9 90 36 Minus − − - - Nutrient credits
• Manure/Compost 72 89 72 89 • Soil (previous crops) 0 n/a (High) 0 n/a (Med) • Other Sources (e.g. irrigation) 0 0 0 0 Equals = = = = Agronomic Balance 18 (deficit) -80 (excess) 18 (deficit) -53 (excess)
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Table 3. Replacing the pelleted chicken manure (a fertilizer) in ‘Baseline’ with a source of mechanically separated dairy solids (primarily a source of organic matter) decreases the plant-available nitrogen (N) and phosphate (P2O5). The nutrient credits for the manure or solids depends on the total N and P (greater in the manure than the solids), the portion of plant-available N in the year of application (50-60% for the manure; 15-20% for the dairy solids), and the application rate. Scenario 3: replace manure Baseline with separated dairy solids lb N/acre lb P O /acre lb N/acre lb P O /acre 2 5 2 5 Crop nutrient recommendation 90 9 90 9 Minus − − - - Nutrient credits
• Manure/Compost 72 89 3 9 • Soil (previous crops) 0 n/a (High) 0 n/a (High) • Other Sources (e.g. irrigation) 0 0 0 0 Equals = = = = Agronomic Balance 18 (deficit) -80 (excess) 87 (deficit) 0 (balanced)
Table 4. Replacing a cereal rye with hairy vetch (ploughed down in the spring) as a cover crop provides additional nitrogen (N) to the next crop without adding phosphate (P2O5), a strategy to help meet crop N requirements without building up excess soil P. Nitrogen credits can be more accurately estimated from the publication, Estimating Plant- Available Nitrogen Release from Cover Crops by Sullivan and Andrews (2012). Scenario 4: plough down a Baseline leguminous cover crop lb N/acre lb P O /acre lb N/acre lb P O /acre 2 5 2 5 Crop nutrient recommendation 90 9 90 9 Minus − − - - Nutrient credits
• Manure/Compost 72 89 72 89 • Soil (previous crops) 0 n/a (High) 45 n/a (High) • Other Sources (e.g. irrigation) 0 0 0 0 Equals = = = = Agronomic Balance 18 (deficit) -80 (excess) -27 (excess) -80 (excess)
Where does this leave us with determining the “Right Rate”?
• Although there are various reasons to use composts (manures), it is often difficult to use them to satisfy crop requirements for both N and P without exceeding P requirements. • Each number in the tables is a guess, some more grounded in evidence than others. The first NMP provides educated guesses. With more experience and data collection on soils and manures, the accuracy of the guesses in the NMP improves and so does the use of crop nutrients. • It is best to think of Right Rate (or ‘agronomic rate’) as being the process by which nutrient management is distinguished from waste disposal. • Ultimately, soil testing can be to provide feedback on the progress towards the right rates: . For N, if post-harvest soil nitrate (NO3) (0-12 inch depth) is above certain thresholds year-after- year and crop yields and quality have been good, N application rates should be reduced:
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♦ Above 45 parts per million (ppm) NO3-N for annual crops, 30 ppm for perennial crops. . For P, soil fertility levels are high in most soils across the Lower Fraser Valley of BC and one ought to question whether additional P is needed on these soils if crop yields and quality have been good. Nitrogen is most likely the limiting nutrient, not phosphorus.
This introduction to “Right Rate” considered agronomic balances, not crop removal balances. The latter is helpful to determine maximum application rates to manage the increase of high soil test P levels. For a more thorough analysis of the 4 R’s, producers can complete an NMP with help from a planning advisor (www.bcefp.ca). The NMP tools are currently targeted towards forage crops and field vegetable crops in British Columbia. Alternatively, contact the author for more information and bookmark the Ministry’s Nutrient Management webpage: http://www2.gov.bc.ca/gov/topic.page?id=46843E0F54024AC2A4917865F0B5C377.
References
B.C. Ministry of Agriculture. 2015. Soil Test Phosphorus and Potassium Converter, version 2. [Excel spreadsheet]. Available online at http://www2.gov.bc.ca/gov/topic.page?id=3EB56F723724400BB4C95D77B68C023B
Sullivan, D. M. and Andrews, N.D. 2012. Estimating Plant-Available Nitrogen Release from Cover Crops. PNW 636. Available online at http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/34720/pnw636.pdf
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Cover Crops to Achieve Multiple Farm Goals
James LaChance and Mitch Hunter Penn State University, University Park, PA [email protected]
The use of diverse cover crop mixtures to achieve multiple farm goals is an emerging and rapidly growing area of farmer interest. Our research explores some of the benefits and tradeoffs of using cover crop mixtures in organic feed grain rotations, and this summary specifically highlights issues of cover crop timing, termination, and general management to aid in farmer insight and adoption of cover crop mixtures. In addition to these considerations, we also discuss goals of weed suppression, nitrogen retention, and nitrogen supply, as they relate to the use of winter cover crop mixtures in central Pennsylvania. Background information on our research project can be found at the following website: http://agsci.psu.edu/organic/research-and-extension/cover-crop-cocktails.
Timing, Termination, and General Management
To make the most of cover crop mixtures, first identify the goals you want from the mixture. These can include: build organic matter, fix nitrogen, supply nitrogen to the following cash crop, suppress and manage weeds, attract pollinators and beneficial insects, and produce fall and/or spring forage. Once you have decided the desired goal(s), we suggest you identify the planting windowi.e., will the mixture be planted in late summer, or early or late falland then begin to select species that fit in this window. This means selecting species that can be planted earlier or later and still establish adequate winter cover. When originally selecting species for our cover crop mixtures research, we considered cover crop species phenology and functional type, i.e., is the cover crop species winter hardy or will it winterkill, and is it a grass, brassica, or legume? For a comprehensive look at useful cover crop species, we suggest Managing Cover Crops Profitably, a Northeast Sustainable Agriculture Research and Education publication (available in PDF for free here: http://www.sare.org/Learning-Center/Books/Managing-Cover-Crops- Profitably-3rd-Edition).
The following chart summarizes the seeding rates for our cover crop “cocktail” mixes.
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The figures below show fall and spring cover crop biomass for our cover crop monocultures and mixtures. These figures show averages of 2 years of data from our research station experiment.
Fall biomass is measured in late October and spring biomass is measured in early to mid-May, just before cover crop termination. Red clover established poorly and our mixtures were dominated by cereal rye in the spring. A lower seeding rate of cereal rye might be beneficial for establishing an even mixture, and future research will attempt to answer this question.
When managing cover crop mixtures in the spring, we suggest terminating mixtures that include cereal rye while it is still “in the boot,” so that it will not become lignified. Lignified rye has a very high carbon:nitrogen (C:N) ratio, which means that it can tie up soil nitrogen when it is plowed down, which in turn can have a negative effect on the yield of the following cash crop.
Weed Suppression
Our goals for weed suppression from our cover crop mixtures were to 1) keep weeds from setting seed and 2) grow cover crops, not weeds. Keeping weeds from setting seed is good preventative maintenance for fields it will keep the weed seedbank down, reducing future weed problems. Another reason to keep weeds out of cover crops is that the weeds are unlikely to provide the same benefits that cover crops will, especially when the mixture includes legumes. As a result, good weed suppression can help increase your cover cropping return-on-investment, because you get more benefits for the buck.
We set out to answer the following questions regarding cover crop weed suppression: 1) Which cover crops work best? 2) Do mixtures help? 3) How do cover crops suppress weeds? What we found can help farmers succeed with cover crop mixtures.
In our trial, cover crop mixtures worked just as well as the best monocultures (see the left graph, below). This is encouraging for farmers who want to use mixtures. For instance, the two legume monocultures (clover and pea) were the weediest. However, when these less-competitive species were combined with grasses or brassicas, the mixture still controlled weeds well.
We found that rapid fall growth is the key to keeping weeds out of cover crop stands (see the right graph, below). This is likely because weeds have the best chance to get established right after the soil has been tilled prior to planting cover crops. After this window, it is hard for weeds to get established until the soil is tilled again. Surprisingly, even winter-killed cover crops (oat and radish) suppressed weeds well the next spring! This finding may help farmers design mixtures that are easier to manage in the spring.
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Overall, we recommend that cover crop mixtures contain 1-2 species that grow very quickly in the fall. After that, you can add in more species to achieve additional goals. Finally, it is important to plant cover crops with care to help achieve a good stand, because any bare spots will become weedy.
Nitrogen Retention
The behavior of cover crop mixtures is strongly affected by the characteristics of the species in the mix. We suggest considering whether a cover crop species will be winter hardy or winter-killed, and also considering its functional typewill it largely supply its own nitrogen through fixation from the atmosphere (e.g., legumes) or will it scavenge for nitrogen (e.g., grasses and brassicas). To retain nitrogen and prevent its leaching from your farm fields, we suggest including a low seeding rate of a winter hardy grass or brassica in your winter cover crop mix, since these species will scavenge soil nitrogen and therefore retain it in your fields.
This figure below illustrates the amount of nitrate leached at 12 inches depth below various cover crop treatments from planting in August to termination in early May (Figure credit: Charlie White). From left to right, the amount of nitrate leached decreases. As the cereal rye seeding rate increases (shown as a percent of the monoculture seeding rate, which is 124 pounds per acre), the ability of the winter cover crop to retain nitrogen also increases. However, it is important to note that all of the mixtures (in the green box), as well as the canola and rye monocultures, did an excellent job at retaining nitrogen. All of the cover crop treatments shown in the green box retained 90-95% of nitrate that was lost in the fallow (no cover crop) treatment (far left, in the red box). The fallow treatment lost approximately 100 pounds of nitrogen per acre. All of that lost nitrogen could have been used to feed your cash crops!
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Nitrogen Supply
To supply nitrogen, we suggest including a well-adapted legume in your cover crop mixture. Through nitrogen fixation, legumes can acquire additional nitrogen from the atmosphere, which can become available to the following cash crop when the legume is plowed down the following spring. Nitrogen will be mineralized and supplied more readily by cover crop biomass that has a lower C:N ratio (approximately 20:1 or lower is best). As a general rule, the C:N ratio of a given species begins to increase rapidly as it becomes “stemmy” ,“woody”, or “lignified”. At the same stage of growth (e.g., vegetative, reproductive, mature), legumes typically have the lowest C:N ratio, brassicas have intermediate C:N ratios, and grasses have the highest C:N ratios. However, most non-legumes will achieve a C:N ratio above 20:1, if allowed to mature.
The figure below illustrates the major impact that cover crop C:N ratio had on our corn yield. As the C:N ratio of our cover crop biomass increased (from left to right), the yield of the following corn silage declined. On the other hand, the cover crop with the lowest C:N ratio (winter pea) provided a large yield boost over the fallow control. The figure shows how the increase in cereal rye seeding rate correlated with an increase of C:N, likely leading to immobilization of nitrogen by microbes in the soil, making much of the soil N unavailable for the following cash crop.
In our research, cereal rye dominated our mixtures and we terminated them too late for optimal corn yields. We suggest aiming for more evenness in your cover crop mixtures. Moreover, when managing mixtures, especially those dominated by cereal rye or winter hardy brassicas, we suggest early termination
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of the cover crop before the C:N ratio of the mix gets too high. We do not want to imply that cereal rye cannot be a good cover crop. Indeed, if it is late in the fall, rye may be the only viable option. However, the many benefits of rye need to be balanced against its tendency to lignify quickly in the spring. One promising approach is to include rye (and other fast-growing non-legumes) at a low rate in mixtures with other species, and then terminate the mixture before it gets too mature.
Key Takeaways
To date, we suggest these guidelines when working with cover crop mixtures on your farm: • Weeds: Include 1-2 species that provide fast ground cover in the fall, then add species to achieve other goals. • Insects: To support beneficial insects for pollination or biological control, manage mixtures to include flowers. • Nitrogen: Combine a well-adapted legume with a low seeding rate of a winter hardy grass or brassica. • Overall: Aim for balanced biomass from all species in the mix to benefit from a range of functions.
For more information about our research with cover crop mixtures, please see our website at: http://agsci.psu.edu/organic/research-and-extension/cover-crop-cocktails
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Acknowledgements
Figures and information described in this summary are credited to the entire Cover Crop Cocktail research team at Penn State University, with specific credit to Charlie White (nitrogen figures) and Mitch Hunter (weeds figures). This research was made possible by USDA-OREI and NIFA funding.
This material is based upon work supported by the National Science Foundation under Grant No. DGE1255832. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
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Evaluating Techniques for Better Blueberry Pollination
Elizabeth Elle and Kyle Bobiwash Dept. of Biological Sciences, Simon Fraser University, Burnaby, BC [email protected]
Pollinators are essential for the production of blueberries. Our research in blueberry has demonstrated that losses (in fruit number and weight) due to insufficient pollination can be very costly to growers.
Managed honey bees are the main pollinator of blueberries, brought to fields in large numbers during bloom. Honey bees are not as effective at pollinating flowers on a per-visit basis as bumble bees, however. In some cultivars like ‘Bluecrop’, honey bees, tend to “rob” flowers of nectar rather than pollinating them. As part of the Integrated Crop Pollination Project (www.icpbees.org), we have been investigating how we can provide pollination insurance to blueberry growers through a combination of managed bees of different species, and supporting and growing populations of wild bumble bees.
We have compared visit rates and pollination deficits in BC with those of our collaborators, finding that visit rates by honey bees are lower in BC than in Oregon, Michigan, and Florida, even though stocking rates are similar. BC tends to have more wild bumble bees, but Michigan has a greater diversity of wild bees overall. We measured pollination deficits by comparing ambient pollination by the bees in the field to hand-pollinated flowers. If we can increase yield, that means there isn’t enough pollination in the field. We found that deficits continue to be high in BC, but they don’t occur in Michigan. This may be because they have more wild bees present.
We added commercially available bumble bees to some fields but were not able to improve pollination, and neither were our Michigan collaborators. In Michigan, collaborators have planted habitat enhancements (flowers that bloom before and after blueberry, but not during blueberry bloom). Over time these lead to larger wild bee populations, and their data indicates that after 3-4 years the increase in pollination can lead to better profits. We are interested in knowing if such enhancements will work in BC, where our pollination deficits are more severe. We planted enhancements on 5 farms last fall, and will report back at a future short course to let you all know how it goes!
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Weevils in Blueberries: Identification and Management
Tracy Hueppelsheuser British Columbia Ministry of Agriculture, Abbotsford, BC [email protected]
Why Worry About Weevils?
Weevil larvae feed on and girdle the roots, causing plants to decline, reduce yields, and can kill young plants. Weevil Adults feed on new growth, which can kill new buds and branches. Washed blueberry roots will reveal extensive ‘tracking’ from larval feeding. Adults feed on one-year old wood and will girdle stems and branches. This can kill new plants. Blueberry plant crowns can be girdled from weevil feeding, particularly if the plants are buried too deep. If feeding has occurred in recent years, feeding damage is not as deep, lighter coloured, with limited callusing. If feeding is older, and chronic, the tracks are deeper, darker, and there is more callusing by the plant.
Basic Weevil Life Cycle
Weevils have 4 life stages, and each species has slightly different timing. Weevils are primarily nocturnal, feeding in the evening and night and seek cover during the warmer days in the soil, or in shady plant foliage. Most root weevil species that affect blueberries do not fly, but are strong walkers. There is one generation a year. Adults can live for more than one year. Some species present in BC berry crops are all female, and lay viable eggs without mating. Some species do have both males and females. There are 6-7 larval instars. Weevils spend about 10 months in the soil as larvae and pupae, where they are well protected.
Surveys
2007 Blueberry Weevil Survey: Four species were recovered in summer: black vine weevil (Otiorhynchus sulcatus), strawberry root weevil (O. ovatus), rough strawberry weevil (O. rugosostriatus), obscure root weevil (Sciopithes obscurus). One early spring feeding species was recovered: clay coloured weevil (O. singularis). 43% of sample fields had weevils damage or insects recovered.
2012 Blueberry Weevil Survey: Seven weevil species in four genera were found. Five were expected and found in the earlier survey: strawberry root weevil, clay coloured weevil, black vine weevil, rough strawberry weevil, and obscure weevil. However, two new ones were found in blueberry fields: Barypeithes pellucidus “hairy spider weevil” and Polydrusus sericeus “green immigrant leaf weevil”. In the 2012 survey fields, 38% fields had pupae and larvae and 54% fields had root damage.
Weevil History
Most of the species are invaders to North America from Europe, suspected to have been brought in on potted plants. Otiorhynchus species (black vine weevil, strawberry root weevil, rough strawberry weevil) were first recorded in eastern North America in the early 1900s, and spread across continent. The green immigrant leaf weevil was first recorded in eastern North America in Connecticut prior to 1934 (Britton, 1934), and has now been confirmed in BC blueberries (Humble & Hueppelsheuser, 2012). The tiny hairy spider weevil was first recorded in New York in 1886 and has been in the West for some time.
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Biology and Identification of Main Weevil Species
• Green Immigrant Leaf Weevil: Shiny green, can fly, both males and females, up to 7 mm long. Hosts: birch, other woody plants, including berries and ornamentals. Adults are day feeders and can be found up high on the plant during May-June. • Hairy Spider Weevil: Brown, small weevil, <4 mm. Can be a pest of berry and nursery crops. Seen in early spring, not found in summer. We found it sporadically in blueberries; it was the earliest pupating weevil we have seen (pupated in February). Because of its small size, damage to roots may be less severe. • Black Vine Weevil: Biggest (1 cm) and a very common species in many crops, including berries, ornamentals. It overwinters mainly as larvae, but 10-15% of the population as adults. It pupates in May, and new adults emerge mid-June, feed on foliage (‘notching’) for up to 4 weeks, then lay 100+ eggs from mid-July through August. • Clay Coloured Weevil: New adults emerge from the soil in March and feed on new buds and bark on 1-year old wood. Adults are inactive in the summer; there is limited evidence of feeding activity. • Obscure Weevil: Life cycle timing is similar to black vine weevil: adults are present in June. However, adults are smaller, slender, with distinct wavy patterns on back, brown & tan in colour. ‘Notches’ are smaller, relative to black vine weevil notches. • Strawberry Root Weevil: Smaller than black vine weevil, ~ 5 mm long, black to plum-colored, with a rough surface and no spots; appears ‘shiny’. Adults often appear later than black vine weevil. • Rough Strawberry Weevil: Medium size, deep brown colour. Life cycle similar to clay coloured weevil. Adults are inactive during July to mid-August. Rarely observed feeding on foliage at night; will find adults in soil & at base of plants. Hard to find; feeding is often very low down on plants, i.e., in sucker growth.
Regardless of species, significant root damage occurs in Winter and early Spring from overwintering larvae.
Carabid Beetles
Predators of pests, these are “good guys”. They can be confused with weevils! Carabid beetles are active in evening and night on the ground. They are various sizes, depending on species, and most are bigger than weevils. They are fast runners, much faster than weevils. Don’t spray them!
Some Considerations
Small plants can be heavily compromised or killed by weevils after only a year of feeding. Mature plants can decline and under-produce, or be killed after years of larval feeding. It is difficult to find larvae in root systems, but damage is relatively easy to find, particularly if populations are increasing. Overall, blueberry plant decline appears to be a result of various factors, including: weevils, disease organisms, sub-optimal soil type, pH, and deep planting.
Monitoring: How to do it?
Daytime visual sampling: Look for feeding symptoms, day or night: Adults ‘notch’ leaves; however, this may be difficult to notice on blueberries. Pull up suspect plant to look for larvae around roots, and then wash roots to look for damage. Alternatively, can excavate soil around roots and look for damage on roots
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while still in the ground. This can be time-consuming and not very productive as it is hard to see new damage on dirty roots.
Evening and night sampling: Use a drop sheet; shake vines after dusk. Or, use a beating tray: rap branches over the big white surface. Count the weevils that drop onto the sheet or tray.
Regardless of method used, sample many locations within a field in order to get a better understanding of the weevil impacts throughout the field. Record the number found, and the species. If you are unsure, take the insects found or the entire plant (with roots) to the Plant Health Lab (BC Ministry of Agriculture) for verification.
If you find weevils, or recent damage to roots, take action! Numbers of weevils collected cannot predict the amount of damage. Knowing change over time is useful, i.e., is weevil presence increasing or changing in a field? What species is here? Talk to field scouts about weevils to ensure they are looking for damage and insect presence. Pay particular attention to poor areas, borders, and new fields.
Management
Weevil management is ongoing, year-round. Take an Integrated Pest Management (IPM) approach: use multiple tools. No single tool will solve the problem, but every little bit will help! Weevil infestation is usually spotty in a field; consider this when monitoring and planning management. Weevils usually move in from the field edges, and can be introduced in containers (particularly if those containers have been sitting by hedgerows or wild treed areas for some time before planting out).
Insecticide: Target is the adult weevil. It needs to be warm enough that the adults are up and actively feeding, which can be an issue if evenings are still cool or rainy in spring and early summer. Coverage is important; depending on the species, could stay down low on plants in sucker growth (i.e., rough strawberry weevil), or be up high during day time (i.e., green weevil). Registered insecticides for weevils in BC (from Berry Production Guide) are: Exirel (cyantraniliprole), Actara 25WG (25% thiamethoxam), Malathion 85 E (85% malathion). Admire (imidacloprid) as applied for aphid control will also help to suppress weevils if adults are present at time of spraying. http://productionguide.agrifoodbc.ca/guides/14/section/16/chapter/36
Met 52 (Metarhizium anisopliae): Mixed in media nursery stock, this pathogenic fungus will protect plants for two years. Met 52 drenched in established plants does not work well. Root ball, weevils below reach of drench, larvae live a long time and move around roots. Met 52 is currently registered for use in Canada in some crops including nursery stock (non-food plants) and strawberries. Research in blueberries and weevils was done at Oregon State University.
Beneficial nematodes: Some species have shown adequate suppression of weevil larvae. However, consider that larvae are throughout root system, so not necessarily near soil surface, which makes getting the nematode drenches to the larvae difficult. Plan to use when larvae are young and closer to surface (Aug-Sept). Remember, nematodes need moisture to move and survive; water before and after application, apply in a band application along the base of plants.
Where to get more information: • BC Berry Production Guide; • BC Ministry of Agriculture Plant Health Lab; • Washington State University; • Oregon State University.
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What is Needed to Get Your Products Listed in a Major Supermarket?
Ken Clark Overwaitea Food Group, Langley, BC [email protected]
The retail food business today all starts with the customerbut satisfying the customer these days is getting more complicated. While the customer expects quality, variety and selection of products, price and value has become a main focus. They are focused on stretching their food dollars by purchasing more groceries as a whole on deal. However, consumers are information hungry when it comes to the products they purchase. They want to know where the product comes from, the ingredients and nutritional information so they can make the right choice that fits within their family and health conscious lifestyle. For all of us it is important to focus at all times on what the consumer wants, when they want it and how they want it.
It is important to understand the ever-changing consumer trends:
• Today, we see consumers trading down to less expensive items within a category, or even out of specific categories. • Consumers commonly seek value by buying less per trip and buying larger quantities to “stock up” on specials. • Consumers want high quality & low prices, all at the same time.
It is critical to understand evolving consumer purchase demands, decisions and expectations! Consumers have high expectations as it pertains to food safety, traceability, animal welfare and environmental sustainability. The consumer’s mindset is that these are just a given, and it is part of being in the food business.
It is continually important to always understand the wants and needs of the consumer. Understanding these wants and needs opens up opportunities of doing business with the Retailer. Potential and current Supplier Partners need to always look at where there are opportunities for business growth. Retailer and Supplier partnerships are the key to gaining these insights. Suppliers need to be open to change based on what the consumer wants and needs.
Food Retailing is not just a food business but it is a people business. The success is a partnership throughout the value chain, from Producer to Retailer to Consumer, all communicating with each other. Consumer expectations about food are ever-changing and continually evolving. Expectations are evolving and vary among demographic segments and by market. Consumers are expecting and demanding more each and every day. Today it is fairly easy to get product on to the shelf under the right criteria; the real challenge is getting the consumer to buy it off the shelf. In simple terms, if it does not work for the consumer, it will not work for any of us within the value chain.
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Taking a Good Look at Irrigation Water is a Good Idea
Justin Falardeau and Siyun Wang, Land and Food Systems, UBC, Vancouver, BC Pascal Delaquis, Agriculture and Agri-Food Canada, PARC, Summerland, BC [email protected]
Irrigation water is an important risk factor in the production of field crops. Microbial pathogens including parasites, bacteria and viruses that cause human diseases can survive in surfaces waters for long periods of time. The microbiological quality of surface waters used for irrigation is influenced by many factors including their proximity to sources of contamination, local hydrogeology and climate, among others. Water quality can change between locations and in time, particularly between seasons.
There are no rapid or simple methods to detect all microbial pathogens in water that could present a danger to human health. For this reason, we continue to rely on the presence of “bacterial indicators” to estimate the risk that irrigation water is safe for use. All of the important microbial pathogens spend some of their life cycle in the intestines of animals and fecal matter is the most important source. Inexpensive methods have been developed to detect bacteria that normally live in the intestines, including the so- called fecal coliform bacteria and E. coli. In BC, irrigation water quality standards have been set at less than 200 fecal coliforms and less than 77 E. coli per 100 mL for the irrigation of crops that are meant to be eaten raw.
Unfortunately, the fecal coliform and E. coli counts do not always provide an accurate measure of risk. Another important drawback is that they do not predict what type of pathogens may be present in water. Intense research to find alternatives continues, but it could be many years before they are adopted. In the meantime, targeted studies can provide important information about the types and numbers of pathogens in irrigation water supplies in a given region and how their numbers vary over time.
Over the last two decades numerous outbreaks of disease caused by verotoxigenic E. coli (VTEC) bacteria (E. coli O157:H7, for example) have been linked to contaminated water and to fresh produce, primarily leafy vegetables. Little is known about the occurrence of these bacteria in surface waters used to irrigate crops in the Lower Mainland. A study of four watersheds (Sumas River, Nicomekl River, Serpentine River and Lower Fraser) for a one year period showed that verotoxigenic E. coli were found in 19.1% of water samples analyzed (Table 1). The rate of detection was not the same in each watershed, however, and was noticeably lower in the Lower Fraser. Local land use, hydrogeological factors and climate effects are probable causes of such differences. We examined the influence of recent weather on the rate of detection and found that temperature and average precipitation three days before sampling were significantly correlated (p<0.05) with the presence of VTEC in surface samples when the data were pooled. The probability of correlation varied between watersheds, however, and neither factor was correlated with VTEC recovery in the Nicomekl watershed. These results illustrate how local conditions can affect contamination of specific watersheds and underline the importance of detailed and long term assessments of water quality.
New research in this area will include a survey of irrigation water used on farms in the Lower Mainland of BC. The purpose will be to further investigate the risk factors associated with foodborne pathogens in irrigation water, with the aim of developing preventative methods through the use of predictive modelling. Phase I of this survey will be conducted in 2015-2016 and will include farms located in Richmond, Delta, Cloverdale, Aldergrove, and Abbotsford. Sampling will be conducted monthly and bi- weekly during the off season and production season, respectively. During the off season (October to March), samples will be taken from source water ditches located adjacent to the farms. During the production season (April to September), samples will be taken directly from the irrigation water as it is
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being applied to the crops. Each water sample will be tested for the presence of three of the most common foodborne pathogens: VTEC, Salmonella, and Listeria monocytogenes.
The resulting data will then be used to develop a predictive model using geographical information system (GIS) software. GIS is a computer system that can layer many different types of spatial information such that relationships between locations, and/or within a single location, can be recognized. Information such as distance to other farms, types of land-use in the surrounding area, or frequency and/or quantity of precipitation, can be reviewed. Ultimately, these data will lead to the development of maps that can show the relative risk associated with any source water in the surveyed area. These maps will be an important tool when assigning land for agricultural use, as well as in developing further strategies to reduce the risk of pathogen occurrence. This will no doubt benefit the growers by increasing their confidence in the quality of their irrigation water and hence the safety of their products.
Table 1. Number of water samples analyzed and number samples containing verotoxigenic E. coli in 20 sampling sites in the Fraser, Sumas, Nicomekl and Serpentine river watersheds sampled between November 2012 and November 2013. No. of positive water samples and Watersheds No. of water samples detection rate (%) Lower Fraser 65 6 (9.2%) Sumas 97 21 (21.6%) Nicomekl 86 20 (23.2%) Serpentine 82 16 (19.5%)
Total 330 63 (19.1%)
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Table 2. Correlation between temperature, precipitation and verotoxigenic E. coli recovery from surface waters in the Lower Mainland. Results of analyses performed for all data and that collected in Lower Fraser, Sumas, Nicomekl and Serpentine River watersheds are shown.
Environmental Correlation with p2 factor1 verotoxigenic E. coli occurrence
Lower Fraser T -0.206 0.008* Tb -0.239 0.002* P 0.056 0.475 Pb 0.187 0.017*
Sumas T -0.387 0.005* Tb -0.391 0.005* P -0.023 0.875 Pb 0.276 0.052
Nicomekl T -0.015 0.925 Tb -0.009 0.957 P -0.062 0.684 Pb -0.018 0.908
Serpentine T -0.415 0.007* Tb -0.353 0.023* P 0.106 0.509 Pb 0.078 0.626
All data T -0.194 0.011* Tb -0.218 0.004* P 0.062 0.421 Pb 0.196 0.010*
1 Environmental factors: T – Mean temperature (°C) on the day of sampling Tb – Mean temperature (°C) for three days before sampling P – Precipitation accumulation (mm) on the day of sampling Pb – Cumulative precipitation (mm) for three days before sampling 2 Probability of correlation between the environmental factor and occurrence. * denotes significance (p< 0.05).
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Nitrate Accumulation in Vegetables: Something to Avoid
Michael Bomford Sustainable Agriculture and Food Systems, Kwantlen Polytechnic University, Richmond, BC [email protected]
Organically-grown products tend to have a different nutritional profile than their conventional counterparts [1]. Relative to conventionally-grown products, organic fruits and vegetables tend to have a higher dry matter content, more magnesium, and more antioxidants. Organic produce tends to have lower synthetic pesticide residues, and lower nitrate content. Nitrate content is the focus of this presentation.
Eating fresh vegetables, especially leafy greens, offers a range of health benefits. Leafy greens are rich in fiber, vitamins, minerals and beneficial antioxidants. They are also the primary source of dietary nitrate, which may be beneficial in moderate quantities, or harmful in excess. Nitrates are thought to help prevent gastro-intestinal infections [2], protect against heart disease [3], reduce blood pressure, and allow us to exercise longer without getting tired [4]. Excessive nitrate consumption has also been implicated as a contributor to miscarriage, poor fetal growth, birth defects, childhood onset of diabetes mellitus, hypertension, and “blue baby syndrome,” in which excess nitrates bind with hemoglobin to reduce oxygen transport, causing coma or death in infants in severe cases [5]. A 2010 report by the International Agency for Research on Cancer concluded that “ingested nitrate… is probably carcinogenic to humans” [6], but more recent studies do not support this assertion [7].
The US Environmental Protection Agency recommends that consumers limit daily dietary nitrate intake to 7.0 milligrams of nitrate per kilogram of body weight [8]. The World Health Organization (WHO) is more conservative, recommending less than 3.7 mg per kg of body weight, or less than 240 mg for a typical 65 kg adult. Leafy greens often accumulate more than 2,500 mg of nitrate per kg of fresh weight (Table 1), meaning that eating 100 g of lettuce or spinach could exceed the WHO’s acceptable daily intake of nitrate.
Table 1. Classification of vegetables according to nitrate content (mg/kg fresh weight). From Santamaria, 2006 [9]. Note that nitrate concentration tends to be highest in leafy greens.
Growing practices influence nitrate content of vegetables. Nitrates dissolved in the soil solution are taken up by plant roots, and then transported to the leaves, where they are reduced to nitrites by a light-activated
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enzyme before the nitrogen they contain is ultimately incorporated into amino acids, plant proteins, and enzymes. The accumulation of nitrates in leaves explains the higher nitrate content of leafy greens, relative to other produce.
Plants grown soil that is rich in nitrate tend to have higher nitrate content in the leaves. The fact that organic growers are not allowed to use synthetic forms of nitrogen fertilizer, which tend to be highly soluble, helps explain the observed difference in nitrate content between organic and conventionally- grown produce.
Plants grown under low light conditions tend to have higher nitrate accumulation in the leaves because the enzyme that converts nitrate to nitrate requires light to function (Figure 1). Plants grown under cool conditions take up nutrients from the soil solution more slowly than plants grown under warm conditions, resulting in less potential for nitrate accumulation in cold weather.
All of these interacting factors have real-world implications for organic farmers growing cool- season greens in the winter using low tunnels, high tunnels, or a combination of both. The winter climate of the Fraser Valley is typified by short, cloudy days, offering little light to drive the plant enzyme that breaks down nitrate. Low-input season extension toolslike row covers, low tunnels, and high tunnelsfurther reduce the light available to the plants they protect. They also trap heat radiating from the soil, warming the plants’ microenvironment, and increasing their nitrate uptake.
Hydroponic growers address the problem of nitrate accumulation in winter-grown leafy greens by eliminating the nitrate component of the growing medium before harvest, and using artificial lights to activate the enzyme that breaks down nitrate. Such management practices are not feasible in low-input, soil-based production systems, like those that can be certified as organic.
Before my recent return to British Columbia, I Figure 1. Rate of increase in activity of spent ten years in Frankfort, Kentucky, which nitrate reductase under three light intensities. has a winter climate comparable to Vancouver’s Nitrate reductase is the light-activated (Figure 2). The seasonal and daily temperature enzyme that breaks down nitrate in plants. fluxes tend to be more pronounced in Frankfort (Nicholas et al., 1976 [10]). than Vancouver, but the daily high temperature in wintertime is about the same.
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Figure 2. Annual temperature flux in Vancouver, BC (maroon) and Frankfort, Kentucky (grey). Width of bars spans average daily high and low temperatures for each month.
As in the Fraser Valley, many organic farmers in Kentucky are able to extend the harvest period for cool- season leafy greens through most of the winter using high tunnels, row covers, or a combination of both. A Kentucky organic farmer with a long history of growing cool-season leafy greens in high tunnels was concerned that his system might be producing greens with unacceptably high nitrate content. His concern led one of my undergraduate students at Kentucky State University, Brittney Wyatt, to conduct a study to better understand the impact of row covers on the nitrate content of high tunnel-grown kale.
‘Red Russian’ kale was direct-seeded into freshly-tilled, compost-amended raised beds, covering a 5 by 10 m area in a 9 by 12 meter high tunnel on certified organic land on September 13, 2011. The high tunnel was clad with two layers of 0.15 mm thick plastic. Kale rows were spaced 1.2 meters apart, with a single line of drip irrigation tape running along each row. The area planted to kale was divided into four equal blocks, and each block was divided into four equal plots, which were randomly assigned to one of four treatments: 1) No row cover; 2) Light row cover (15 g/m2); 3) Medium row cover (30 g/m2); or 4) Heavy row cover (68 g/m2). Row cover treatments were left in place for the duration of the study.
Air and soil temperatures were recorded in each plot every hour using temperature sensors located 5 cm above and below the soil surface. Kale was harvested on November 10th, 2011, and on January 31st, 2012, 58 and 140 days after seeding. Each harvest consisted of the removal of all aboveground biomass from a one-meter row section in each plot; the second harvest was collected from a different row section than the first. Both harvests were collected near noon on clear days, and the amount of photosynthetically active radiation reaching the plant canopy was measured immediately before harvest using a ceptometer. The fresh weight of all harvested plant material was recorded before plant sap was extracted to quantify nitrate concentration using a nitrate-specific probe.
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Figure 3. Average daily temperature flux in air (left) and soil inside and outside a high tunnel near Frankfort, Kentucky, between September 2011 and January 2012. Grey lines show temperatures beneath light, medium and heavy-weight row covers inside the high tunnel.
Over the course of the study, soil 900 temperatures averaged 8 °C outside the high tunnel, and 13 °C inside. The heaviest row 800 A cover boosted average soil temperature by an 700 additional 1 °C, on average, with lighter row covers offering less warming (Figure 3). Air 600 B temperature reached the freezing point under PAR 500 the lightest and heaviest row covers when (µmol/s/m2) C outdoor air temperature reached -3.5 and -5.3 ±S.E. 400 CD D °C, respectively. 300 The high tunnel reduced light penetration to 200 the plant canopy by 35%. Light, medium, and heavy row covers inside the high tunnel 100 reduced light penetration by 48%, 52%, and 0 61%, respectively (Figure 4). Outside Bare Light Medium Heavy Row covers The heaviest row cover reduced kale yield Inside high tunnel relative to the medium row cover by the Figure 4. Photosynthetically Active Radiation (PAR) November harvest, and relative to all other at harvest outside and inside a high tunnel, and beneath treatments by the January harvest. No other light, medium, and heavy-weight row covers inside the significant treatment effects on yield were high tunnel. All readings were collected at canopy observed (Table 2). height. Bars labeled with the same letter do not differ significantly different (Tukey’s HSD test, α=0.05, n=4).
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Table 2. Effect of row cover weight on yield and nitrate content of high tunnel-grown winter kale. Means followed by the same letter within a column do not differ significantly (Tukey’s HSD test, α=0.05, n=4).
November 10 January 31
Yield Yield Nitrate content (kg/m) (kg/m) (mg/kg) and Rating Treatment
No cover 1.90 ab 3.80 a 330 b (Low)
Light cover 2.40 ab 3.66 a 560 b (Med)
Medium cover 2.80 a 3.63 a 800 b (Med)
Heavy cover 1.38 b 2.21 b 1850 a (High)
Nitrate content of kale grown under the heaviest row cover was more that of kale grown under the medium-weight row cover, and almost six times that of kale grown without row covers (Table 2). Row cover weight and nitrate content of kale were positively correlated (Figure 5).
The experiment clearly demonstrates the potential for row cover weight to influence nitrate accumulation in kale. It suggests that daytime use of heavy-weight row covers should be avoided inside high tunnels, since they reduce crop yield and light penetration and contribute to greater nitrate accumulation.
A common practice in high tunnels is to remove row covers in the daytime, and replace them before Figure 5. Relationship between row cover night, when plants most need of protection from weight and nitrate content in organic kale low winter temperatures. This practice almost harvested from a high tunnel in wintertime. certainly reduces nitrate accumulation in high tunnel grown leafy greens. If row covers are left in place permanentlyas they were in this studythen light-weight covers should be preferred, to allow sufficient light penetration to the plant canopy to activate the nitrate-reducing enzyme. Other practices likely to reduce nitrate accumulation include removing row covers well before harvest and preferentially harvesting on sunny afternoons in wintertime.
This article describes an applied research study conducted by one of my undergraduate students in Kentucky to address concerns raised by a small-scale organic vegetable farmer in the state. Now that I have returned to British Columbia to teach in Kwantlen Polytechnic University’s Sustainable Agriculture program, I look forward to many more opportunities to mentor undergraduate students conducting applied experiments like this. KPU’s Sustainable Agriculture Program emphasizes applied research, and requires students to design, conduct, analyze, and present an applied research study over the course of a full year. This is one way that the program achieves its goals of integrating classroom and farm-based learning, and teaching the practical foundations and practices of healthy farming within a sustainable food system.
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Please feel free to contact me if you have an applied research question that you would like our students to address.
References:
1. D. Lairon and M. Huber. 2014. Food quality and possible positive health effects of organic products. Chapter 16 in Organic Farming, Prototype for Sustainable Agriculture, S. Bellon and S. Penvern, eds. Springer. Pp. 295-312.
2. G.M. McKnight, C.W. Duncan, C. Leigert, and M.H. Golden. 1999. Dietary nitrate in man: friend or foe. British Journal of Nutrition 81: 349-358.
3. J.O. Lundberg, M. Carlström, F.J. Larsen, and E. Weitzberg. 2011. Roles of dietary inorganic nitrate in cardiovascular health and disease. Cardiovascular Research 89: 525-532.
4. S. Lidder and A.J. Webb. 2013. Vascular effects of dietary nitrate (as found in green leafy vegetables and beetroot) via the nitrate-nitrite-nitric oxide pathway. British Journal of Clinical Pharmacology 75: 677-696.
5. US-Environmental Protection Agency. 2007. Nitrates and Nitriles: Toxicity and Exposure Assessment for Children’s Health. Accessed on 2/27/2015 from http://www.epa.gov/teach/chem_summ/Nitrates_summary.pdf
6. International Agency for Research on Cancer. 2010. IARC monographs on the evaluation of carcinogenic risks to humans. Ingested nitrate and nitrite, and cyanobacterial peptide toxins. 94: 1-412.
7. N.S. Bryan, D.D. Alexander, J.R. Coughlin, A.L. Milkowski, and P. Boffetta. 2012. Ingested nitrate and nitrite and stomach cancer risk: An updated review. Food and Chemical Toxicology 50: 3646-3665.
8. US Dept. of Health and Human Services. 2013. Nitrate/Nitrite Toxicity: What Are US Standards and Regulations for Nitrates and Nitrites Exposure? Agency for Toxic Substances and Disease Registry. Accessed on 2/27/2015 from http://www.atsdr.cdc.gov/
9. Pietro Santamaria, 2005. Nitrate in vegetables: toxicity, content, intake and EC regulation. Journal of the Science of Food and Agriculture 86: 10-17.
10. J.C. Nicholas, J.E. Harper, and R.E. Hageman. 1976. Nitrate reductase activity in soybeans (Glycine max [L.] Merr.) I. Effects of Light and Temperature. Plant Physiology 58: 731-735.
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Keeping Food Safe to Eat: From Producer to the Consumer
Alison Speirs BC Ministry of Agriculture, Abbotsford, BC [email protected]
Fresh Produce Hazard Assessment 2014 Survey
Why is Produce Potentially High Risk?
• Fresh produce has been linked to a number of foodborne illnesses; • Retailed as “ready-to-eat” or perceived as such by consumers; • Often consumed without a “kill step”no cooking or processing; • Limited BC data available on BC produced and retailed products to characterize the food safety risk.
Research Objective
• To measure the level of foodborne pathogens in fresh, consumed-raw BC produce at retail.
Methods
• Sampled BC grown fresh produce commonly consumed raw; • Sampled at six retail types: . Small chains, large retailers, roadside stands, direct farm retail, farmers’ markets and independent retails (produce stores). • 167 different retail locations samples; • 1146 samples collect August 1 to September 28, 2014; • Types of samples collected: . Berries (blueberry, blackberry, raspberry and strawberry), 50% of samples; . Culinary herbs (basil, mint, parsley, dill, cilantro and chives), 25% of samples; . Leafy greens (salad mix, kale, green leaf, butter, red leaf and romaine), 25% of samples. • Samples analyzed for Salmonella spp, E.coli, Shiga Toxigenic E.coli (STEC) and Aerobic Colony Count (ACC).
Results
• All samples were negative for Salmonella spp. and STEC; • ACC showed no relationship to other organisms tested; • All samples had E.coli levels below the Health Canada’s standard of <1000cfu/g for fresh produce; • 13 samples had >100 cfu/g but <1000 cfu/g E.coli, which is considered instigative.
Observations
• Quality of water used on farm was unknown in some cases: . Surface water may be used; . Should be tested annually; . Records need to be kept.
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• Water use and product washing controls: . Product washing occurs throughout the produce distribution system, bulk tank washing needs to follow procedure to keep water bacterial quality good; . Different product hydration techniques need to have controls in place, tubs used for dips, spray bottles, herbs stored in stagnant water; . Cleaning and disinfection of product washing areas require their procedures to be reviewed. • Animal based soil amendments: . Records regarding composting should be provided by the supplier of the compost; . Adjacent row application and neighbouring property needs to be monitored by grower. • Hand contact: . Product is being handled, from the farm to the consumers while shopping; . Produce is exposed to sources of contamination, not covered or protected from dust, dirt, people, hands. • Lack of temperature control: . Product is frequent displayed for retail outside of refrigeration, no cooling; . Retailed in the summer, sometimes no protection from sun. • No designated area to wash equipment: . Washing procedures lacking, infrequent, inadequate use of sanitizers; . Exposed wood surfaces found. • Lack of product traceability: . No labels; . Records are inaccurate; . Labels on boxes not accurate.
Summary
95% of the samples collected met the Health Canada’s guidance of ready-to-eat foods for E.coli; all samples met the Health Canada Standard for fresh produce.
While samples were collected and follow ups were conducted, a number of areas of improvements were observed.
Resources
Funding is available through ARDCorp’s On-Farm Food Safety Program through Growing Forward2, a federal-provincial-territorial initiative.
Resources are available through BC Ministry of Agriculture: • BC GAP Guide, posters, templates, employee training • Workshops; • Technical advice and guidance.
Horticulture Growers' Short Course 159 Organics
Post-Harvest Handling of the Vegetable Mix: Tips for Success
Bruce Wisbey Wisbey Veggies, Abbotsford, BC [email protected]
Post-harvest handling of vegetables starts in the field: • Crop rotations: A build-up of diseases and pests will occur over time that can affect quality if the same crop is grown year after year in the same spot. An example is root knot nematodes.
• Weed control: Good management in this area makes it easier to find the crop for cultural operations such as thinning, monitoring and treatment for pests. Good weed control decreases competition for nutrients and allows for more even sizing.
• Precision seeding: Using a precision seeder such as the Stanhay precision seeder is a good option for many vegetable crops to achieve consistent spacing and sizing. For example, Wisbey Veggies has had success growing quality carrots using a combination of precision seeding, raised beds and carrot varieties that are tolerant or resistant to foliar diseases.
• Harvesting: . Pre-grading in the fieldleave culls behind. . Time of dayaim for early morning harvesting to help reduce field heat in harvested crops. . Use reflective coverings on wagons to reduce heat build-up in harvested crops. . Crop is placed into the washer as quickly as possible in order to take the field heat out of the crop. A hydro-cooler is ideal for this. . Any cooler is better than none, but each crop requires different cooling methods. Different coolers should be used for vegetables that have different storage requirements (i.e. temperature and RH). o Leafy vegetablesvacuum cooler. o Beansforced air. o Broccoliicing. o Corn, broccoli, carrotshydro-cooler.
• Field Handling: . Limit drops when dumping buckets. . Place cabbage, instead of dropping it. . Educate workforce to handle produce gently.
• WashlineRoot Crops . Dirt eliminatorremoves loose soil. o Dry soil is easier to handle than mud. . Keep drops to a minimum of 6 inches by using slides, padding; remove rollers under drops, and slow movement with belting. . Food Safetypotable wash water used. o Need a potable water source. Dirty water must not be recycled as washwater. o Try to have good separation between dirty and clean operations. For example, dirt removal should be as far away as possible from the bagging operation.
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o Final rinseusing bleach at 150 ppm (based on past research) to reduce storage disease issues like black rot, grey mold. . Use a roller table for grading. . Packaging: o Use bulk 25 lb bags. o Bagging machines for 3 to 5 lb bags.
• Cooler Design: . Cooler capacity is never large enough. . Temperature Differential: o The narrower the temperature differential between the evaporator coil and the condenser, the lower the rate of dehydration to the stored product. o Although it costs more money, it pays to use large evaporator fans. . Insulation: o FibreglassR24 for walls and R40 for the roof. o Foam is preferred over fibreglass, because foam is water resistant and relatively more resistant to mildew and other pests. . A curtained door is a good idea to keep the temperature stable when moving product in and out.
• Movement to Market: . Use refrigerated trucks. . Don’t leave product on the loading dock. Get it into the truck or cooler as quickly as possible. . It takes harvested vegetables 12 hours to cool down to the appropriate storage temperature. It only takes 1.5 hours for vegetables removed from the cooler to warm back up to ambient temperatures. . Doing a good job of removing field heat from produce and maintaining the cold chain through to market will dramatically affects shelf-life in a positive way.
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Post-Harvest Vegetable Handling Techniques and Tips
Harvie Snow Snow Farms Ltd., Delta BC [email protected]
Snow Farms grows over 70 acres of certified organic fresh-market vegetables for the Vancouver wholesale market. Our product mix includes 30 vegetables; approximately 80 varieties.
Seventy percent of our product is sold out of the field, while 30 percent is stored product. We produce approximately 100 semi-loads of product annually. Seventy-five loads pass through our 1300 square foot cooler. Most of our product is grown 6 kilometers away from our packing and shipping facility.
Our crops include bunched greens including Swiss chard, parsley, kale, spinach, cilantro and few bunched beets. We grow heading crops such as cabbage, broccoli, cauliflower, lettuce, celery, kohlrabi and leeks. Fruiting crops are zucchini, cucumbers, winter squash, pumpkins; along with a few tomatoes, peppers and eggplant. Finally, we grow root and tuber vegetables which include beets, celeriac and potatoes. Our crop mix is rounded out with onions and French shallots.
Most wholesalers have a requirement for pre-cooling of leafy greens. We have a general exemption from this for the following reasons: • Bunched greens are harvested during the morning hours. • Product is boxed soon after bunching. • Boxed product is kept out of direct sun. If boxes of harvested product accumulate prior to removal from the field, they are stacked with the boxes on the top of the stack flipped upside down, to cover the opening in the top of the box. • We use a two-hour rule for removal of the boxed product from the field to the cooler. • All greens are soaked with cold water prior to placement in the cooler. • We use twin cooling units that combined, are over size for the volume of the cooled space. • We have a 72 hour maximum hold time target for all of our greens. • Cooler temperature is 1 degree Celsius. • Humidity is maintained by keeping the floor wet.
Our strategy for harvesting and handling heading vegetables includes:
• Harvesting when the morning dew is off the crop, depending on the time of year. • Lettuce is boxed immediatelytwo cutters, one packer. • Cabbage, cauliflower, broccoli, celery, kohlrabi and leeks are harvested into field bins and transported to cooler as quickly as possible. Bins may be covered with a tarp if the two-hour rule is exceeded. We have a tarp with a reflective surface on one side, which slows heat accumulation of the product underneath. • As we have potable water at the field, the bins can be soaked down to initiate evaporative cooling prior to transport to the cooler. • We don’t ice broccoli. Harvest bins of product are soaked with potable water prior to packing. Broccoli is packed into waxed cartons prior to shipment. These are thoroughly soaked prior to shipping. Our customers move this product quickly throughout the marketing system.
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Our fruiting vegetables each have specific handling techniques. Zucchini is packed in boxes on the field, palletized and wrapped with stretch film, prior to transport to the packing shed. The film is removed upon arrival and the pallets are kept in a dark, airy location in the packing shed overnight prior to being placed into a cooler that is kept at 10 degrees Celsius. The cooler, near ambient temperature holding period allows the picking scars on the stems to dry out prior to placement in the cooler, which seems to prevent decay in the cartons if the storage time nears a week. This also provides longer shelf-life for our customers. Cucumbers are harvested into field bins which are then placed into the cooler prior to washing and shipping. We wash and pack the product as close to the shipping time as possible. This provides maximum shelf-life for our customers. We grow a small amount of tomatoes, peppers and eggplant. These are harvested into small totes and placed into the 10 degree cooler immediately. Peppers may be washed prior to shipping. Fruiting crops are placed into an auxiliary cooler that is an annex on one side of our main cooler. This structure is as heavily insulated as the main cooler. Duct booster fans draw cold air from the main cooler into this space and the temperature is controlled by a cooling thermostat. The fruiting crops are held at temperatures from 8 – 10 degrees Celsius. When the fruiting crop season is finished, we store washed potatoes in this space and reduce the temperature to 5 degrees Celsius. Most of our winter squash is run through a dry brushing machine which mechanically removes soil and provides a bit of a polish. Soft skinned types such as butternut must be cleaned by hand as the machine will abrade the skin. Root and tuber vegetables in our operation are generally harvested in the fall. These are mechanically topped and dug as required and then we hand-harvest into field bins. As we farm generally heavy clay soils, we want to get these crops out of the ground before the soil becomes too wet. These crops harvested in wet conditions will carry a lot of soil, which will dramatically increase the effort, and of course the cost, of washing them. If beets and celeriac are harvested in relatively dry conditions, we will soak the bins with potable water prior to placing them in storage. We may have to soak them from time to time during the storage cycle. Potatoes are stored unwashed in field bins at a temperature near 5 degrees Celsius. The crop is washed, graded and packed as close to the time of shipment as possible. Onions and shallots are mechanically dug at maturity and windrowed in the field to cure prior to harvest and topping. These crops are mechanically topped using various machines, depending on the situation. If the weather conditions are less than ideal during the curing time, we will artificially dry the crop using forced air and heat. The crops are stored in field totes. As we grow a relatively small amount, each bin is treated separately. We seal the bin as required, then use a furnace blower and an electric construction heater to push warm air through the bins until the outer skins “crackle”. We may have to carry out this treatment two or three times during the storage cycle, depending on the length of storage time. We always run this drying process overnight on product that we are going to grade and pack for shipment. We keep food safety concerns in mind when handling our produce. Washed produce is treated with potable water only. Our packing area with related equipment and tools is hosed down each day with potable water. The equipment and tools may be have contact surfaces sanitized with either a dilute vinegar or dilute hydrogen peroxide solution from time to time. The same treatment is applied to our field totes as well. Our product has the cut surfaces only from harvesting, so there is limited access to pathogens.
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Rodents can present serious problems if control measures are not in place. We have had success using the “Black Cat” bait boxes containing the “Black Cat” spring traps placed at intervals around the outside walls of the packing and storage facilities. The “Black Cat” bait box is the only one we know that can accommodate an armed spring trap. We may fill the bait cup in the trap with peanut butter or will fill the bait compartments of the box with bits of beet or fresh squash seeds. Either type of bait will have some success. Of interest, we have caught more Townsend voles in the traps this winter than Norway rats.
Horticulture Growers' Short Course 164 LMHIA Board-approved Research Projects in March 2015: $36,073
Project Title Researcher(s) Approval
1 Red raspberry cultivar development Dossett 4000.00 2 Evaluation and development of strawberry varieties Dossett 2000.00 3 Cultivars – blueberry breeding and evaluation trials Dossett 1000.00 4 Swede midge monitoring program in south western BC Hueppelsheuser 750.00 Brassicae vegetable crops: Lure purchase for 2015 & 2016 5 Understanding of Potato virus Y complex in Canada & Dessureault/ Singh 4473.00 development of a comprehensive on-farm mgmnt strategy 6 Strawberry planting trials Gerbrandt 1200.00 7 Draper fruit drop (blueberry) Gerbrandt 2000.00 8 Spotted wing Drosophila: towards better understanding Hueppelsheuser 1500.00 of trapping & risk of this new pest in BC berry crops 9 Brussels sprout variety screening trials for the BC Wallis 1000.00 processing industry 10 Carrot and parsnip variety trials Prasad 2900.00 11 Non-target impact of spotted-wing Drosophila (SWD) Prasad 1500.00 sprays 14 Wireworm management in potatoes Kabaluk / Vernon 3000.00 15 Cabbage maggot control: chemical control Prasad 2500.00 16 Blueberry IPM newsletter Teasdale/ Carmichael 1000.00 17 Blueberries fields mobile application Sakalauskas 1500.00 18 Spotted wing Drosophila winter/spring trapping around Hueppelsheuser 2500.00 Fraser Valley berry fields, Winter #6 20 Evaluation of thrips damage to potatoes in a changing Kiara Jack 2500.00 climate 22 Request based on industry need for Carolyn Bedard to Bedard 750.00 attend Chicago conference on global minor use