PLANT PROTECTION CORNER

Innovation in integrated control of greenhouse pests: An urgent need!

In greenhouse crops, PROGRESS IN IPM BASED ON THE modes of action. Traditional biological control as a DEVELOPMENT OF NEW (SYNTHETIC broad-spectrum insecticides like component of Integrated AND MICROBIAL) CHEMICAL organophosphates, carbamates PESTICIDES and pyrethroids have been Pest Management (IPM) ccording to Ramakers, most replaced by selective products went through a considerable of the antagonists used in like nicotinoids, spinosyns and Abiocontrol have been hydrazines. So it is actually the growth in the first years of available for decades, with the progress in the chemical field this millennium, after a phytoseiid mite Typhlodromips that has allowed a wider virtual standstill in the swirskii (predator of thrips and application of biologicals, most whiteflies simultaneously) as a of which were known before! nineties. Already common rare exception. New pesticides, practice in the production however, appear regularly, often LACK OF INNOVATION IN P.M.J. Ramakers representing completely new BIOCONTROL of fruiting vegetables, Courtesy of NAI chemical groups with novel Why is there a lack of innovation biocontrol is now on the increase in floriculture, mainly in cut flowers, and to a lesser extent in potted plants. Moreover, we witness regional expansion from the moderate climate zone towards subtropical areas. The driving force behind the trend is the increasing social and political call for sustainable production. With respect to acceptable pesticide residues on vegetables, supermarkets impose stricter standards than health authorities. In ornamental production, presence of pesticide residues is not so much of an issue. These growers appear to have other motivations: pesticide resistance prevention, labour, environmental concerns, product reputation and sometimes even yield increase. Curiously, while IPM is increasing, little innovation can be observed in the field of biocontrol itself. Why is that so and what needs to be done to change the situation were the two main questions addressed by P.M.J. Ramakers, Wageningen UR Greenhouse Horticulture in the Netherlands, during his excellent keynote lecture at the opening session of the Miami conference.

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in biocontrol? Ramakers sees a of sometimes doubtful quality. with other (chemical or biological) Ramakers concluded his lecture series of reasons to this situation. These doubts relate to the pesticides. by raising the question of First reason is that biocontrol biological effectiveness in the whether investing in biocontrol products are products of nature, first place, to the targets WHAT DO WE NEED? agents pays? He balanced ther not patentable. This is actually recommended and to the sheer For Ramakers, there are four positive and negative arguments. the main reason why there is quality (viability) of the finished pillars to build on in order to The positive ones: an urgent and such a discrepancy between product. The most common error change the situation. increasing demand, a simple chemical versus biological is the translation of petri dish First and most urgent, search for registration procedure (except for innovation. observations into conclusions new pest antagonists everywhere microbials), a market targeting The second reason is that about field efficacy without too in nature, in agricultural well-educated growers who can biocontrol products have a much of evidence. ecosystems and in the area of handle complicated strategies specific mode of action and It may be tenable to leave field pest origin. Next is to develop and used to relatively high therefore there is only a small evaluation to the growers and microbial pesticides such as product prices. market niche for each of them, their advisors in cases where the bacterial insecticides, soilborne On the “negative side”, products with a few exceptions of course. effect of the antagonist is fungi, NP viruses and EP are not patentable, they are niche Biocontrol manufacturers are not obvious. However, with some of nematodes. Then there is a products, the growers are in able to make in-depth the antagonists recently compulsory need to confirm demand for extremely high investments, knowing that fast- commercialized, field evaluation efficacy in field experiments with quality and …..the growers are following competitors will soon is difficult if not impossible since an adequate monitoring of both well educated, which prevents come alongside, often within a the biological interaction with the the pest and the antagonist. Last snake oil products to stay long in year. Hence, innovative efforts are target is concealed. Alertness is but not least, there is a need for the market. Is this really directed at mass-production, particularly recommendable if continuous quality control: those negative? In any case, reliable storing, formulation (of products are claimed to be products are living organisms suppliers to this market will not microbials) and application effective only when used and there is a risk of complain. The biocontrol techniques, rather than at preventively or in combination contamination and genetic drift. industry needs to mature. ■ developing different antagonists. The last but not least reasons listed by Ramakers to explain the lack of innovation in the biocontrol industry are the privatization of independent research & extension services with public and cooperative funds shrinking as well. Biocontrol is thus widely adopted, but based on relatively few products. Considering the huge assortment of botanical species and cultivars in floriculture, grown under a wide variety of climatic conditions, it is highly unlikely that biocontrol can conquer this field with the few antagonists currently available. This gap between growers’ demands and availability in the marketplace has created a vacuum, which seems to suck in new suppliers offering products

NEW AG INTERNATIONAL 27 PLANT PROTECTION CORNER

Role of Mineral Nutrition in IPM

Mineral nutrients are utrients that are known to that the form of K may be more influence diseases in some important than the amount involved in many Nplants are N-form, K, Ca, Cl, applied. physiological and S, Mn, Ni, and Si. SULPHUR biochemical processes as NITROGEN Sulphur (S) deficiency impairs enzyme activators, Nitrogen can be absorbed as a crop productivity and quality. reduced (NH4) or oxidized form Suphur Induced Resistance (SIR) structural components, (NO3). The form of nitrogen denotes the reinforcement of the metabolic regulators, affects disease as diseases can natural resistance of plants react differently to each N-form. against fungal pathogens by substrates, and osmotica. NH4-N is associated with sulphate-based, soil-applied reductions in pH while NO3-N fertilization and is one The nutritional status of a increases pH. N03-N suppresses constituent of the complex plant affects inherent Prof Lawrence E. Datnoff Fusarium diseases. NH4-N phenomenon of induced Courtesy of NAI suppresses most other soilborne resistance. The potential efficacy disease resistance which affects disease escapes, alters diseases. Datnoff developed on of SIR expressed as a reduction pathogenesis, and modifies the virulence of the pathogen several examples such as of the disease index ranged from Fusarium wilt being suppressed 5-50% to 17-35% in greenhouse and its ability to survive. Proper nutrition is first line of by NO3 on tomatoes as well as and field experiments, Rhizoctonia root rot on beets, respectively. defense. Any nutrient that is deficient or in excess will Verticillium wilt being increase a plant’s susceptibility to disease. Because suppressed by NH4 on potato as well as Black root rot on nutrients influence the relationship between the plant and strawberries. the pathogen, growers have a valuable IPM method CALCIUM already in place to effectively reduce damage from plant Ca reinforces cell wall diseases. In his keynote address at the opening session of components to resist infection. It suppresses a number of the New Ag International conference in Miami, Prof diseases such as Club root of cabbage, Southern blight and Lawrence E. Datnoff, Department of Plant Pathology & cavity spot of carrot, Fusarium Crop Physiology, Louisiana State University, and a world wilt of tomato, Erwinia soft rot of potato or Botrytis blight of many expert on the topic, presented the interactions and effects, vegetables. The book of Prof Datnoff is the and prescribed nutritional regimes that will minimize world reference book on the POTASSIUM subject. It can be ordered from crop loss to disease and improve overall plant health and Potassium is absorbed solely as www.shopapspress.org K. Effects on disease are development. numerous and variable. Results CHLORINE often depends on the form of K - Long before the role of Cl in KCl, K2SO4, KNO3. K provides crop production was recognized, proper ion balance and turgor Cl was routinely applied as maintenance. Datnoff underlines chloride in NH4-N, K, and Ca

26 NEW AG INTERNATIONAL PLANT PROTECTION CORNER for Suppressing Plant Diseases

fertilizers. However, even in the Manganese (Mn) content in the metals e.g. Ca, Mg, Mn, Fe, Cu, susceptible cultivars is last decade, the disease- plant. Many disease-suppressing Zn), or certain agrichemicals dramatically improved. Silicon suppressing benefits of chloride activities, such as mulching, no- such as glyphosate, might be also has been shown to suppress salts are still mistakenly being till, cover cropping, green adversely impacting the plant diseases as effectively as ascribed to NH4, K, or Ca, says manuring, will increase Mn endogenous biological fungicides; thus reducing the Datnoff. Soil applications of Cl availability. Mn containing availability of Ni for key disease- number and rate of fungicide influence nitrification, fungicides (Mancozeb (Maneb® associated metabolic processes. applications. Based on these manganese availability, and and Dithane®) are generally findings, silicon may play an beneficial soil microorganisms. more effective than Zineb or SILICON important role in the IPM of plant Chlorine affects osmoregulation, Ferbam. Mn increases host Although silicon is the second diseases. For more information, organic and amino acid defense mechanisms. most abundant element in the readers may refer to the article synthesis, nutrient cycling and earth’s crust, many soils still may written by Prof Datnoff in the root exudation that, in turn, NICKEL be low or limiting in this March 2009 issue of New Ag directly influences the plant’s Accumulating evidence element. Although not International. ■ susceptibility to infection. implicates the essential nutrient, considered an essential nutrient, Datnoff’s presentation explored nickel (Ni), as potentially when silicon is amended to the uses and mechanisms of influencing crop diseases, says silicon-deficient soils, plants suppressing diseases on Datnoff. Effects can be direct may show improved growth and asparagus, beets, celery and control of certain pathogens enhanced plant disease corn with Cl. Suppressed upon contact, resistance. Many components of diseases were: Asparagus increased/decreased host-plant host plant resistance (i.e., lesion (Fusarium crown rot), beets resistance, increased number and size) are reduced; (Rhizoctonia crown rot), celery susceptibility at high consequently, the resistance of (Fusarium yellows) and corn concentration, or a variety of Ni- (Stalk rot, Smut). linked physiological and growth Those treatments that disorders. There is evidence that Plant Nutrients & Diseases resistance: Highlights suppressed disease were excessive usage of transition • N-form is important and will effect certain plant diseases associated with an increase in metal fertilizers (N, P, or divalent differently. NH4-N is associated with reductions in pH while NO3-N increases pH. For example, Nitrate suppresses Fusarium, while Ammonium suppresses Verticillium. • K provides proper ion balance and tugor maintenance. Form of K may be more important than amount. • Ca reinforces cell wall components to resist infection. • Cl suppressed diseases on crop that are tolerant of Cl such as asparagus, beets, celery, and corn perhaps by enhancing Mn uptake. • S is involved in metabolic and disease defensive pathways in the plant. • Ni is an important ‘cofactor’ and/or ‘enzyme activator’ of metabolic and disease defensive pathways in the plant. • Si reinforces cell walls and acts as a signal to elicit plant mediated disease resistance.

NEW AG INTERNATIONAL 27 PLANT PROTECTION CORNER Can potassium nitrate be used as a pest-control agent?

SOLID EVIDENCE DOCUMENTED Florida Wax Scale (FWS) successive years. SINCE MORE THAN 25 YEARS (Ceroplastes floridensis Recently, PN has been found as a otassium Nitrate (PN) was Comstock) was found highly potent anti-fungal agent too. found to produce a negative susceptible to PN sprays over 25 Phytophthora (P. sojae) stem-rot Pchemotaxis for 2nd-stage years ago in Israel (Yardeni & disease was efficiently controlled juveniles of the very common Shapira). PN at 4%, tank-mixed in soybeans in experiments and aggressive nematode with 2% summer oil, sprayed on carried out in Japan (Sugimoto, Meloidogyne incognita. Castro et various citrus species has 2009). Two mechanisms have al, have found in California, USA. controlled 80% of the FWS been identified. PN 1991, that PN presence at larvae, which was a better result concentrations as low as 0.4-10 concentration above 30 mg/L than spraying them separately. mM decreased the release of the creats a chemical protective Due to the importance of this fungus zoospores, while the shield around the root system of pest in Israel, these experiments application of 30mM has tomato plants, that prevents the were practiced several more suppressed the disease mainly by Dr Oded Achilea

Courtesy of M. Loison nematodes from approaching the times with excellent results that accumulation of potassium in the The answer is definitely root system. exceeded the results obtained penetration-stopping sites in the PN sprayed at 1% on pecan trees with highly-toxic and non- cortex layer of the soybean yes, according to Dr Oded in Georgia USA, has reduced selective organo-phosphates, e.g. plants. Achilea, from Haifa Yellow Pecan Aphid chlorpyrifos, carbaryl, methoate, (Monelliopsis pecansis Bissell) ethione. A thinning procedure A NEW TOOL IN IPM STRATEGIES Chemicals Ltd. population by factors of 3–9 aimed at the weak larvae stage in According to Achilea there are Much empiric evidence has during different parts of the the build-up of the FWS two main advantages of using PN growth season, when sprayed at a population, by spraying PN, and its specially-developed accumulated over the years fortnightly schedule, 10 times leaves the natural enemies derivatives for pest management. among Haifa's between April and August. These undisturbed to build up their First, PN is already in wide agronomists, regarding the results were very consistent populations, and allows them a nutritional use for great many during 4 consecutive years, long activity time. This procedure crop species, as a foliar spray pesticidal effects of showing highest effectiveness has kept a certain experiment and a soil- or a nutrigation- potassium nitrate- based against the pest larvae. citrus grove free of FWS during 7 applied product, so best application techniques are products, on different already well known, and can be types of crop pests. easily adapted to the new pest- These types encompassed control application. Second advantage is that PN is mainly spider-mites and considered as an environment- insects. A literature survey safe substance that has expressed so far high specificity has identified recorded against the targeted pests. There evidence of the effects of is therefore, such as for other fertilizers like MKP, an opening potassium nitrate (PN) for an increased usage of also on nematodes and Potassium Nitrate in the design fungi. In his Miami of integrated pest management programmes on a number of lecture, Achilea crops. ■ highlighted such effects.

26 NEW PLANT PROTECTION CORNER Managing grapevine diseases with Ecoswing®

In Miami, Nicolas Cock, President of the Colombian company EcoFlora S.A., presented Ecoswing, a natural fungicide for agricultural use made from plant extracts.

otassium EcoSwing® is a wide acting natural Ppreventive and curative fungicide, which has been successfully used to control powdery mildew (Sphaerotheca pannosa) in roses, acid rot, oidium (Uncinola necator) and Botryitis sp. in grapevines, crown rot in bananas, and other diseases. In order to widen the scope of field tests performed in Colombia (Isabela grapevine variety cultivated in Valle del Cauca), field tests were made in Nicolas Cock several zones of Peru to verify Courtesy of M. Loison the control of acid rot, oidium, clusters and decreased infection and botrytis in other commercial levels in clusters previously grapevine crops. When infected). compared with other products Cock concluded that the results (21,7% control), EcoSwing® obtained using EcoSwing® (99% control) achieved show that it is an ideal product significantly better control of acid to be used in vineyard integrated rot, within the phenological stage disease management plans. of ripening and harvesting of the Further, the use of EcoSwing® fruit. In adition, the product has several advantages over the achieved a comparable level of use of synthetic products. Firtsly control of oidium at a dose of it does not leave toxic residues 2ml/L as Iprodione based and hence it has been shown that chemical product (both it presents no risk to the health treatments achieved 100% of agricultural workers and control of infected leaves and a consumers of the treated fruits stable infection degree in leaves and for this reason it has no pre- previously infected). Finally, for harvest restrictions / period. the control of Botrytis all of the Secondly, being a natural EcoSwing® dose levels tested product that combines a mixture achieved favourable results when of synergistic ingredients, it is a compared to the chemical product of great complexity in its products traditionally used composition, thus reducing the (100% control of the infected risk of pest resistance. ■

NEW AG INTERNATIONAL 27 PLANT PROTECTION CORNER Timorex Gold™: A novel approach for controlling Black Sigatoka disease in Banana

novel product controls the Morpholine, Anilinopyrimidine and respectively. The results also most harmful disease that Spriroketalamina. demonstrate that Timorex Gold™ Aaffects banana: is effective on both conidia and Mycosphaerella fijiensis (Morelet), THE SOLUTION COMES ascospores. Timorex Gold™ also a fungus widely known as Black FROM THE TEA TREE inhibits mycelial growth of the Sigatoka Disease (BLS). Black Timorex Gold™ 24 EC is a natural fungus. Reuveni also showed very Sigatoka, BLS, is considered the fungicide based on an extract of promising results on field trials most damaging and costly disease Melaleuca alternifolia, a plant done comparing young banana of banana and plantain. The commonly know as Narrow-leaved plants in conventional control of the disease accounts for Paperbark or Narrow-leaved Tea- about 30% of the total production tree. This species is native to costs and about 40% yield loss on Australia and it is used for plantain. Greater losses may occur distillation of essential oil. It is the on export banana as a result of primary species for commercial Moshe Reuveni premature ripening, during production of Tea tree oil Courtesy of Reuveni transportation and storage, when (melaleuca oil), a topical Introduced in Miami by control measures fail. Chemical antibacterial and antifungal used in Moshe Reuveni, the control of BLS is achieved with the a range of products including alternation or tank mixing of antiseptics, deodorants, Scientific Director of the protectants and systemic shampoos, soaps and lotions. The management, organic management Swiss-Israeli company fungicides in order to provide a product was developed by Biomor, and a commercial comparison of Stockton Agrimor AG, a sufficient control and to reduce an israeli subsidiary of the Swiss Timorex Gold™ vs. a standard resistance risk. Stockton Agrimor. Timorex Gold™ conventional products protocol product based on Tea tree Many chemical products have is a non residual product, safe to (Triazole, Strobilurine). According oils shows great potential been used against BLS. In fact beneficial insects, environment to Reuveni, Timorex Gold™ some of them such as and humans. It is a tool for exhibits high prophylactic and in the control of the most Dithiocarbamates have been in use Resistance Management, due to it curative efficacy against BLS. damaging disease that for more than 50 years. Others being a multi-component Timorex Gold™ actually have been sprayed in the farms for substance and it has been demonstrates an efficacy affects banana in the more than 20 years such as approved by leading organic comparable to leading systemic world. Benzimidazole, and Ftalonitrilo, associations. fungicides (such as Strobilurines Morpholine, and Triazoles. Among Moshe Reuveni showed several and Triazoles groups). It is widely the “new” products used are data obtained in the lab and in the adopted for large scale use in the Strobirulines, Anilinopyrimidine, field. The in vitro studies show that key banana growing countries in Spriroketalamina and some “soft” Timorex Gold™ is highly effective conventional farms. The product is options such as Bacilus Subtilis against Mycosphaerella fijiensis already registered in most banana- and M. Alternifolia. The problem is spore germination. At growing countries - Colombia, that the fungus has developed concentrations of 0.01% and Costa Rica, Guatemala, Honduras, resistance to most of them: 0.1% Timorex Gold™ provides Nicaragua, Mexico, Republic Dithiocarbamates, Ftalonitrilo, 39% and 100% inhibition, Dominican and Philippines. ■

26 NEW AG INTERNATIONAL PLANT PROTECTION CORNER Managing plant parasitic nematodes with bio-fumigants and bio-stimulants

n recent years the control of many climate change and other enhanced by supplementary foliar plant parasitic nematodes has environmental and management application of seaweed-based bio- Ibeen heavily reliant on synthetic practices. Both pests have the stimulants. In addition some nematicides, resulting in good potential to be controlled by products reduced PCN quality products, but not integrated application of bio- multiplication (Pf/Pi), compared necessarily reducing nematode fumigant and bio-stimulant plant with untreated controls. levels. Following the withdrawal of products. Preliminary trials suggest that these many nematicides a number of plant-based products have the plant-based products are becoming FARMERS MUST REMAIN REALISTIC! potential to accelerate PCN decline available for agricultural use with A series of field trials evaluated the within an integrated management claims to either kill a range of plant effect of plant-based bio- system once optimum treatment pests or to act as a plant bio- fumigants/stimulants on PCN G. regimes are further clarified, but stimulant, enabling crops to better pallida population levels and that farmers must be realistic in tolerate pest attacks. Cyst resulting potato yields and quality. evaluating their effectiveness, S.J Turner (Globodera/Heterodera spp.) and Bio-fumigant formulations derived compared with chemical Courtesy of NAI root-knot (Meloidogyne spp.) from sugar, mustard, garlic and nematicides. This was the topic nematodes are, economically, the bio-stimulant products derived Laboratory tests were performed covered by S.J Turner, most important groups of nematode from seaweed were compared with assessing the effects of seaweed Agri-Food & Biosciences pests of many agricultural and a granular nematicide and untreated extracts and other organic materials amenity sectors. Potato cyst controls. The effect of G. pallida on on the growth of creeping Institute & The Queens nematodes [PCN] (Globodera spp.) growing potato crops was assessed bentgrass and perennial ryegrass University of Belfast in continue to be the most important by tuber yield and leaf tissue infested with Meloidogyne minor. pest of potato in many regions of analysis of essential minerals. The Both bulk seaweed extracts and Northern Ireland, during the world, with their management resulting increase or decline of specific purified fractions her Miami lecture. by nematicides and resistant PCN was also recorded. Results significantly enhanced root growth. varieties limited. Root-knot showed that all bio-fumigant Root knot nematode attack reduced Her conclusion? nematodes have become more products increased both total tuber root growth of both ryegrass and Potential is there but do widely recognised as causing crop and marketable yield, but to varying bentgrass but this reduction was not expect any miracle. damage in recent years, due to extents, and that yield was further ameliorated by biostimulant application. Most biostimulants did At the moment, not affect nematode gall numbers, biofumigants and however application of harpin protein significantly reduced galling biostimulants formulas are in creeping bentgrass roots. With not as efficient as existing the regulatory removal of a number synthetic nematicides but of effective nematicidal products, the control of plant parasitic their role may increase in nematodes in amenity turfgrass has the future, at least for become increasingly difficult. Biostimulants may have a key role certain crops. in the management of nematodes in this sector. ■

NEW AG INTERNATIONAL 27 PLANT PROTECTION CORNER

Marrone Bio Innovations: Regalia® for Control of Fungal and Bacterial Diseases

Marrone Bio Innovations contact effect inhibiting spore germination. was founded in 2006 by Versman showed a massive Pam Marrone in Davis, amount of data based on many trials. Regalia® works in berries, California, USA. The citrus, cucurbits, grapes, leafy company discovers, greens, ornamentals, turf, peppers, pome fruits, stone fruits, develops, and markets strawberries, tomatoes, walnuts. effective and And it controls the following diseases: Powdery Mildew environmentally (Sphaerotheca spp, Erysiphe responsible natural cichoracearum), Gray Mold (Botrytis cinerea), Downy Mildew products (biopesticides) Julie Versman (Bremia lactucae, Peronospora Courtesy of M. Loison that fill unmet needs for spp.), Bacterial Blight A BIOFUNGICIDE FROM (Xanthomonas spp.), Citrus weed, pest & plant disease GIANT KNOTWEED Canker (Xanthomonas spp.), management, said Julie egalia® is a novel Greasy Spot (Mycosphaerella biofungicide extracted from a citri), Bacterial Leaf Spot Versman, VP of Marketing Rplant: giant knotweed (Xanthomonas spp.), Target Spot of Marrone Bio in her Reynoutria sachalinensis. It`s (Corynespora casslicola), main active ingredients are Bacterial Speck (Pseudomonas Miami lecture. Emodin and Physcion. It has syringae), Tomato Late Blight The company focuses proven efficacy in the control of (Phytophthora infestans), Early powdery & downy mildews, gray Blight of Tomato (Alternaria on products that improve mold, bacterial leaf spots and solani) and Bunch rot/gray mold yields and quality in bacterial blights. The product is (Borytis cinera). currently sold in the US, Ecuador Julie Versman also showed very conventional ag compared and in the UK. interesting data in tomatoes, to chemical-only systems, Giant Knotweed`s antibacterial citrus, grapefruit, blueberries, activity was discovered in 1980 cucurbits, melons and lettuce. products that lower the and it´s antifungal effects in 1984. Beyond the specific crop results cost and increase yields Some companies have developed some interesting features of the products based on this plant, product are that it is very resistant in organic farming and such as Compo and KHH BioSci, to rainfall, it has a very good products for water Inc. combination with copper products Regalia® , that was launched in and especially with many other treatment and 2008, induces systemic chemical products such as water bodies. resistance. The product induces Azoxystrobin, Chlorothalonil, plant immune system to produce CU2O, Thiophanate Methyl, phytoalexins, PR proteins, Bacillus Subtilis, Famoxadone + phenolics and antioxidants. It also Cymoxanil, Manganese Ethylene, has a strengthening effect Mefenoxam and Pyraclostrobin. inducing papillae formation and a ■

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