Viticulture Research and Outreach Addressing the Ohio Grape and Wine Industry Production Challenges

HCS Series Number 853

ANNUAL OGIC REPORT (1 July ’16 – 30 June ‘17)

Imed Dami, Professor & Viticulture State Specialist

Diane Kinney, Research Assistant II

VITICULTURE PROGRAM Department of Horticulture and Crop Science

1 Table of Contents Page

Executive Summary……………………………………………………………………………………………………..………….3 2016 Weather………………………………………………………………………………………………………………….……..5 Viticulture Research……………………………………………………………………………………………………….…… 10 Project #1: Trunk Renewal Methods for Vine Recovery After Winter Injury……………………………………… 11 Project #2: Evaluation of Performance and Cultural Practices of Promising Wine Grape Varieties….. 16 Viticulture Production…………………………………………………………………………………………………………….28 Commercial Expansion of Varieties New to Ohio………………………………………………………………………………….28 Viticulture Extension & Outreach……………………………………………………………………………………………41 OGEN and Fruit Maturity Updates………………………………………………………………………………………………………. 41 Ohio Grape & Wine Conference………………………………………………………………………………………………………….. 42 Industry Field Day and Workshops………………………………………………………………………………………………………. 43 “Buckeye Appellation” Website………………………………………………………………………………………………………….. 45 Industry Meetings………………………………………………………………………………………………………………………………. 45 Professional Meetings…………………………………………………………………………………………………………………………. 45 Student Training & Accomplishments…………………………………………………………………………………… 49 Honors & Awards………………………………………………………………………………………………………………….. 50 Appendix………………………………………………………………………………………………………………………………. 51

2 Executive Summary

The year 2016 brought a welcome break from a two-year streak of bad weather and a huge sigh of relief by the Ohio grape community. The 2016 winter was mild resulting in a total crop of 5,000 tons, 43% higher than in 2015 and the largest crop since 2013. The above normal warmth of the growing season was ideal to ripen all grape varieties including the late ones. As a result, the fruit quality was exceptional and it is expected the 2016 wines to be of high quality as well.

The following are highlights of the major accomplishments by the Viticulture Program during the time period between 1 July 2016 and 30 June 2017.

 Completed the 3-year projects on assessing and managing winter-damaged vines and new recommendations were shared with growers on the best pruning and training methods for recovering vines from cold injury. All findings were presented at the Ohio Grape & Wine Conference, and published electronically in factsheets and newsletter articles, and posted on the Buckeye Appellation website.

 Re-established the research vineyards affected by the polar vortex events by planting new varieties to be tested for the first time in Ohio and expanding the best performing varieties for future research on how to grow them.

 The production project, titled “Commercial Expansion of Varieties New to Ohio”, was initiated in 2015 and continued in 2016. Currently, we have 10 vineyards- wineries from all three regions (north, central, and south) of Ohio, that have participated in this project and planted 17 varieties. Some participants will have their first crop and wine made in 2017.

 Two (2) new educational You-Tube videos were produced and posted on Buckeye Appellation titled: “Pruning Grapevines - VSP” and “Grapevine Canopy Management”.

 The Viticulture Program co-organized and participated at the 2017 OGWC and a short course for the annual grape school in northeast Ohio; and delivered eight presentations to nearly 300 attendees; Dami and his group also contributed articles in OGEN and continued the outreach service of monitoring fruit maturity and sharing weekly updates with producers.

 Buckeye Appellation statistics in its 2nd year: the viticulture group updated the website with 121 postings that generated 6,970 session views by 4,787 users.

 Our graduate students continue to perform well at the national stage and Jaclyn Fiola, PhD candidate received four national scholarships. Thomas Todaro, MS, accepted a university position as a Viticulture Extension Educator. Dami’s program also trained four (4) undergraduate students who assisted with all projects during the 2016-2017 season.

Ohio Grape Production (2000-2016)

Production (tons)

9000 8000 7000 6000 5000 4000 3000 Production (tons) 2000 1000 0

4 2016Weather

The weather data were obtained from the OARDC-weather system website at: www.oardc.ohio-state.edu/newweather/. The first quarter of 2016 proved to be a very mild winter with above average mean-temperature, and March was one of the warmest on record with a temperature of 73 oF early in the month. These early warm temperatures encouraged early deacclimation and bud break. The mean temperature during the 2nd quarter was below or near normal. We were fortunate to dodge the bullet and experienced no spring frost in Wooster.

During the growing season, temperature was above normal for six consecutive months (June-Nov) with record high near 90oF in July for ~10 days and unusually warm nights. The warm weather continued during the fall season which helped with a better cold acclimation and extended the growing season to mid-late November before the first killing frost (vs. normal is October 10th). We ended the year with even more challenging temperature swings ranging from 2.7 oF on the 16th of December to 65.8 oF on the 26th. Fortunately, our freeze test showed vines to have acclimated sufficiently with no damage.

As expected, GDD followed the same trend as mean temperature and we finished the season with 3,369 GDD, or 300 GDD above both 2015 and the 30-yr average. Previously, the 3000-mark was reached in 2010 and 2012, both were vintage years.

Precipitation was above the 30-year average in February, March, August and October, but below average in April through July. The relatively dry spell reduced disease pressure thus clean fruit throughout harvest. The wet October (1.25” average) was a bit of a spoiler and made harvest more interesting. Even with all the fluctuations, we ended the year at only 1” greater than the long term average with a total rainfall of 32.47”.

5 Fig.1 Monthy Mean Temperature - Wooster 80.0

70.0

60.0

50.0

40.0

30.0 Temperature (F) 20.0

10.0

0.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

2015 2016 30-yr avg (1982 - 2011)

Fig. 2 Deviation from 30-year average - 2016 Temperature - Wooster

9.0 8.0 7.0 6.0 F) o

( ( 5.0 4.0 3.0 2.0 Temperature 1.0 0.0 -1.0 -2.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Deviation from Average

6 Fig. 3

Monthly GDD - Wooster 800 700 600 500

400 GDD 300 200 100 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

2015 2016 30-yr Avg (1982-2011)

Fig. 4

Cummulative GDD - Wooster 4000

3500

3000

2500

2000 GDD 1500

1000

500

0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

2015 2016 30-yr Avg (1982-2011)

7 Fig. 5 Monthly Precipitation - Wooster 6.00

5.00

4.00

3.00

2.00 Precipitation (inches) Precipitation

1.00

0.00 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

2015 2016 30-yr avg (1982-2011)

Fig. 6

Cumulative Precipitation - Wooster 40

precipitation (inches) 10

0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

2015 2016 30-yr avg (1982-2011)

Fig. 7 Collection: 24 February 2017, Wooster 4 2 0 -2 -4 LT50 (F) -6 -8 -10

Fig. 8 Collection: 13 Mar 17, Wooster 10.0 5.0 0.0 -5.0

LT50 (F) -10.0 -15.0 -20.0

9 Viticulture Research

The OSU Viticulture Program is involved with three major research areas based on the strategic plan developed by OGIC. The research focus areas are:1) Mitigation of winter freeze and spring frost injuries in grapes; 2) Improving fruit and wine quality using sustainable production practices in vineyards and wineries; and 3) Evaluation of viticultural and enological performances of grape varieties, clones, and rootstocks new to Ohio. The following projects were funded during FY17 and are described in details in this section.

1) Trunk Renewal Methods for Vine Recovery After Winter Injury

2) Evaluation of Performance and Cultural Practices of Promising Winegrape Varieties

10 Project #1: Trunk Renewal Methods for Vine Recovery After Winter Injury

OSU Investigators: Imed Dami and Thomas Todaro

Trial Location: Ferrante Vineyards, Geneva

Project Type: Research and Extension

Status: Completed

Objectives:

Almost all cold tender varieties sustained die-back (trunk damage) or died in 2014. Recovering vines that produced new growth (canes) were damaged again after the freezing events in February 2015. The responses of vines to back-to-back cold stress events are unknown and dealing with “re-damaged” vines requires special practices in the vineyard. Many vinifera growers are faced with this situation during the 2015 season. The central dilemma is what is good for the vine is not necessarily good for the grower’s bottom line. It is the purpose of this study to answer the question “how can the grower strike a balance between producing a healthy vine while generating some revenue?” The goal of this project was to provide growers with objective and research-based information that outlines the pros and cons of the different training systems.

Procedures:

This trial started during the spring of 2015 and Thomas Todaro, OSU graduate student established three training systems using varieties at AARS in Kingsville and at Ferrante Vineyards in Geneva (Figure 1). Treatments consisted of training new shoots (suckers), that emerged from live buds (buried in 2014), on one of three (3) training systems: 1) fan system; 2) VSP (industry standard); 3) a combination of fan and VSP. In 2015 (year 1), data were collected on damage of buds and canes above ground and under the soil mound. Canopy growth (leaf area) was measured, and yield and fruit composition were collected. In March-April 2016 (year 2), vines were trained back to the existing VSP system and different spur and cane pruning combinations (Figures 2 & 3). Timing of pruning, training, and managing each system were recorded (Figure 4).

Figure 1. Schematic diagram of the three training systems used after the winter damage in 2015. Training was conducted on green shoots (suckers) during the 2015 growing season.

Figure 2. Schematic diagram of the five training systems used after the winter damage in 2015. Training was conducted on dormant vines during early spring of 2016.

Figure 3. Photos showing the five training systems during the 2016 growing season.

Results: • This study provides evidence that training systems with high bud number have increased shoot number and yield but delayed fruit ripening. • Fan trained vines produced the highest amount of first year yield and required the lowest initial retraining time compared to VSP and Fan/VSP trained vines. Although the Fan training provides total flexibility to select virtually any training system the following year, that freedom comes with increased training time in year 2 as the conversion from Fan to F-2T2C and F-4T4C required the longest retraining time of all other treatments due to the requirement of cane selection and tying (Figure 4). • Aside from the benefit of lowest required initial retraining time, producing highest first year yield with a balanced crop load, a major advantage of Fan and Fan/VSP compared to VSP training was evident during fall 2015 and spring 2016 as they allowed fall cane burial in 2015 and optimal cane selection in spring 2016 for trunk renewal and conversion to bilateral VSP training. • There were no differences in fruit composition between Fan and Fan/VSP training systems (Table 1).

13 • Although the clusters were located close to the ground and not netted, there was no mechanical damage of clusters during the growing season by tractors and there was not a concerning amount of crop lost to rot or pest predation (birds, bees, raccoons). • Conversely, in year 1, VSP training required the highest retraining time, and did not produce a yield or allow for cane burial or optimal cane selection. However, in year 2, VSP-4T4CS required less training time than F-2T2C and F-4T4C as the VSP framework was already established and thereby eliminated the time required to select and tie canes. VSP-trained vines were reduced to only 4 shoots (suckers) per vine during initial retraining and did not allow for cane burial in fall 2015 or any further cane selection in spring 2016. • VSP-4T4CS produced the largest number of shoots and clusters per vine compared to all other treatments (Table 1), which may translate to increased costs to the grower due to the potential need for intense shoot and cluster thinning, and leaf removal.

Conclusion: It is concluded that trunk quality (morphology) and quantity (number) is critical for vine rehabilitation after winter damage, and the fan training system produced the most optimum renewed trunks. Practically, grape growers will benefit from this research by implementing the best practices for trunk renewal by training all shoots (suckers) using a fan system in year 1, and selecting and retaining 4 trunks and 4 canes with optimum size and removing “bull” canes in year 2. The findings from this research will enhance the economic and environmental sustainability of grape production in Ohio.

Figure 4. Time of pruning and tying of the five training systems in Cabernet franc grapevines.

Table 1. Yield components and fruit composition of different training systems of Cabernet franc grapevines grown at a commercial vineyard in Geneva, OH in 2016.

Yield components Fruit composition Treatmentz Clusters /vine Cluster wt (g) 100-Berry wt (g)x Yield /vine (kg)w Pruning wt (kg/m) Crop loadv TSS (%)u pH TA (g.L-1)t F-2T2C 21 c 100 b 147 ab 2.1 c 0.26 bc 7 c 20.78 a 3.36 a 4.95 a F-4T4C 30 b 93 bc 159 a 2.8 b 0.31 ab 9 bc 19.83 ab 3.35 a 5.33 a F/VSP-4T4C 28b 89 c 148 ab 2.5 b 0.24 c 10 abc 20.10 ab 3.33 a 5.03 a F/VSP-4T4CS 33b 92 bc 141 c 3.1 b 0.24 c 13 a 19.25 b 3.36 a 5.03 a VSP-4T4CS 42a 122 a 140 c 5.2a 0.35 a 12 ab 18.83 c 3.35 a 4.88 a P VALUES <0.0001 0.0392 0.0048 0.0345 0.0133 0.0321 0.0035 0.7278 0.4384

zF-2T2C, F-4T4C, VSP-4T4CS, F/VSP-4T4C, F/VSP-4T4CS: 2015 Fan trained vines converted in 2016 to bilateral VSP system of 2 trunks and 2 canes (cane pruned), 2015 Fan trained vines converted in 2016 to bilateral VSP system of 4 trunks and 4 canes (cane pruned), 2015 VSP trained vines maintained to bilateral VSP system of 4 trunks and 4 canes (spur pruned), 2015 Fan/VSP trained vines converted in 2016 to bilateral VSP system of 4 trunks and 4 canes (cane pruned), 2015 Fan/VSP trained vines converted in 2016 to bilateral VSP system of 4 trunks and 4 canes (spur pruned), respectively. yMeans followed by different letters in columns are significantly different at p ≤ 0.05. x1 g = 0.0353 oz. w1 kg = 2.2046 lb. v Crop load = ratio of reproductive and vegetative growth computed using the following equation: ((yield /vine (kg))/(pruning wt /vine (kg)). uTSS = total soluble solids measured as percent soluble solids in juice. tTA = titratable acidity measured as grams of tartaric acid per liter of juice (1 g.L-1 = 1000 ppm).

15 Project #2: Evaluation of Performance and Cultural Practices of Promising Winegrape Varieties

Investigators: Imed Dami, Diane Kinney, Andrew Kirk, and Todd Steiner Project Type: Research and Extension Status: On-going Trial Location: OARDC-Wooster, AARS-Kingsville

Objectives:

The OSU Viticulture-Enology Program has evaluated more than 40 varieties in the past 10 years. The majority of recent variety planting in Ohio results from recommendation by the OSU viticulture and enology program. Examples include: Cabernet franc, Pinot gris, Chambourcin, Traminette, Noiret, Marquette, LaCrescent, and Frontenac to list a few. Variety evaluation consisted of recording the viticultural and enological performances and identifying the pros and cons of these varieties grown under Ohio climates. From this project, we have identified more than 10 varieties that performed well and thus have been recommended for planting commercially in Ohio.

In 2014, the evaluation trial in the Wooster site sustained 70% vine loss (vs. 20% in Kingsville). So far, we have 3-years’ worth of data from the Wooster trial, but only 2 years from Kingsville. The Kingsville plot has many varieties that were planted later than in Wooster thus vines are young and don’t have sufficient data to make any recommendations. Furthermore, at recent meetings (Tri-county growers’ association and AARS advisory committee) in northeast Ohio, most growers ranked variety evaluation as a high research priority. For those reasons, Dami continued the trial in Kingsville by replacing dead/missing vines (20%). Due to extensive loss (70% dead vines) at the Wooster site, all vines were removed except for one row. In 2016, vines did not sustain any cold damage and we had a full crop in Kingsville for the first time since 2013.

Results:

• In 2016, Dami established new trials at the Wooster site with the most promising varieties by planting larger number of vines per variety to conduct research on best practices to grow these varieties in Ohio. Additionally, Dami and his group planted new varieties and clones to be tested for the first time in Wooster.

• In April 2017, we continued replanting the variety block in Wooster and replaced dead and missing vines and varieties that underperformed in Kingsville. Nine (9) new varieties, and three (3) new clones of Sauvignon blanc were planted in Wooster and

16 Malvasia was planted in Kingsville for the first time (Tables 1 and 2).

• Viticultural performances of varieties grown at AARS during the 2016 growing season:

 Phenology: the earliest varieties to break buds were: Arneis and Muscato (9 May) and Tocai Fruilano was the latest (23 May)(Table 3).  Harvest date: The earliest varieties were Siegerrebe and Pinot noir precoce (15 September). The latest variety, Petit Manseng was harvested 2 weeks later on 18 November.  Yield: Sauvignon blanc clone FPS 7 and Moscato produced the lowest yield at 2.13 tons/acre. The highest yield was from Gruner Veltliner at 9.03 tons/acre (Table 5).  Vine size (vigor): Lowest pruning weight: Arneis at 0.13 lb/ft. Highest pruning weight: Albarino at 0.48 lb/ft (Table 5).  Vine balance: The lowest crop load (yield per vine / pruning per vine) belongs to Albarino and Sauvignon blanc FPS7 at 2 and the highest crop load was from Gruner Veltliner at 19 (Table 5).

• Crown gall incidence: Table 6 shows % crown galls (CG) in 2015 and 2016. Pinotage is very susceptible to CG. But, some varieties had low CG including Kerner, Ortega, Regent, Sauvignon blanc FPS7 and FPS27 and Siegerrebe.

• As part of Best Viticulture Practices (BVP), petioles were collected from varieties showing leaf symptoms of nutrient deficiencies. Tissue analyses confirmed low and deficient nutrients mainly N, P, Ca, and B. K was generally high to excessive (Table 7). Lime and fertilizer amendments were applied in 2017.

• Due to poor performance at AARS, Refosco was removed in 2016. Since this variety underperformed in both Wooster and Kingsville locations, we do not recommend this variety.

• In 2016, Todd Steiner and his group resumed vinification of varieties grown in Kingsville and wines were made from the following: Arneis, Dolcetto, Gamay noir, Gruner Veltliner, Kerner, Petit Manseng, Regent, Sauvignon blanc clone FPS14, Sauvignon blanc clone FPS25, Sauvignon gris, Siegerrebe, Teroldego, and Tocai Friulano.

17 Table 1: Vinifera wine grape varieties planted at OARDC-Wooster as of June 2017.

Variety Clone Color Rootstock Planting date

Albarino (New) FPS 01 W 101-14 2016-2017

Arneis FPS 01 W 101-14 2016-2017

Cabernet franc 11 R 101-14 2010

Chardonnay FPS 37 W 101-14 2010 - 2017

Dolcetto FPS 02 R 101-14 2016-2017

Fernao Pires (New) FPS 1 W 3309 2016-2017

Malvasia FPS 03 W 101-14 2016-2017

Merlot FPS 03 R 101-14 2016-2017

Petit Manseng (New) W 101-14 2016

Pinotage FPS 01 R 101-14 2016-2017

Regent R 101-14 2010 - 2017

Sauvignon blanc (New) FPS 01 W 101-14 2016-2017

Sauvignon blanc FPS 07 W 101-14 2016-2017

Sauvignon blanc FPS 14 W 101-14 2008 - 2017

Sauvignon blanc (New) FPS 18 W 101-14 2016-2017

Sauvignon blanc (New) FPS 26 W 101-14 2016-2017

Sauvignon blanc FPS 27 W 101-14 2016

Syrah FPS 07 R 101-14 2016-2017

Touriga brasiliera (New) FPS 01 R 3309 2016

Teroldegao FPS 02 R 101-14 2016-2017

Tocai Friulano (New) FPS 01 W 101-14 2016-2017

Trousseau (New) FPS 10.1 R 101-14 2016-2017

Verdejo (New) FPS 1.1 W 3309 2016-2017

Verdelho (New) FPS 11.1 W 3309 2016-2017

Viosinho (New) FPS 1.1 W 101-14 2016-2017

18 Table 2: Vinifera wine grape varieties planted at AARS-Kingsville as of August 2016.

Variety Clone Color Rootstock Planting date

Albarino FPS 01 W 101-14 2009 Arneis FPS 01 W 101-14 2008-2015 Cabernet Franc* FPS 01 R 101-14 2008-2015 Chardonnay FPS 37 W 101-14 2010-2015 Dolcetto FPS 01 R 101-14 2008-2015 Durif (P. Syrah) FPS 03 R 101-14 2008-2009 Gamay noir FPS 05 R 101-14 2008-2015 Gruner Veltliner FPS 01 W 101-14 2008-2015 Kerner FPS 01 W 101-14 2010 Malvasia (new) FPS 03 W 101-14 2016 Moscato giallo VCR 133 W 101-14 2012-2015 Ortega NA W C-3309 2012-2016 Petit Manseng NA W 101-14 2009-2016 Pinot noir* FPS 13 R 101-14 2008-2015 Pinotage FPS 01 R 101-14 2009-2015 Pinot noir precoce NA R 101-14 2010 Refosco** FPS 03 R 101-14 2008-2012 Regent NA R 101-14 2008-2012 Sangiovese FPS 14 R 101-14 2009 Sauvignon blanc FPS 07 W 101-14 2008-2016 Sauvignon blanc FPS 14 W 101-14 2009-2015 Sauvignon blanc FPS 25 W 101-14 2009-2015 Sauvignon blanc FPS 27 W 101-14 2009-2015 Sauvignon gris FPS 01 W 101-14 2009-2015 Siegerrebe FPS 02 W 101-14 2008-2015 Teroldego FPS 02 R 101-14 2009-2016 Tocai Friulano FPS 01 W C-3309 2010 * Benchmark (control) Varieties **Removed in 2016.

19 Table 3: Phenology of vinifera wine grape varieties planted in AARS-Kingsville in 2016.

Variety Bud Break Bloom Veraison Harvest Albarino 16-May 20-Jun 25-Aug 31-Oct Arnies 9-May 20-Jun 2-Sep 5-Oct Chardonnay 13-May 17-Jun 29-Aug 5-Oct Dolcetto 13-May 20-Jun 22-Aug 18-Oct Durif 20-May 22-Jun 25-Aug 31-Oct Gamay Noir 13-May 20-Jun 25-Aug 5-Oct Gruner Veltliner 18-May 20-Jun 29-Aug 27-Sep Kerner 13-May 17-Jun 22-Aug 21-Sep Muscato 9-May - - 29-Sep Ortega 18-May 20-Jun - 5-Oct Petit Manseng 18-May 20-Jun - 18-Nov Pinot Noir Precoce 18-May 20-Jun 9-Aug 15-Sep Pinot Noir FPS13 (Martini) 18-May 20-Jun 25-Aug 22-Sep Pinotage 18-May 20-Jun 22-Aug 14-Oct Refosco 13-May 20-Jun Removed Removed Regent 20-May 20-Jun 9-Aug 7-Oct Sangiovese 20-May 20-Jun 2-Sep 2-Nov Sauvignon Blanc 16-May 20-Jun 2-Aug 26-Sep Sauvignon Blanc 7 18-May 20-Jun 2-Sep 28-Sep Sauvignon Blanc 14 16-May 20-Jun 2-Sep 28-Sep Sauvignon Blanc 25 16-May 20-Jun 2-Sep 28-Sep Sauvignon Blanc 27 18-May 20-Jun 2-Sep 28-Sep Sauvignon Gris 13-May 20-Jun 2-Sep 28-Sep Siegerrebe 13-May 20-Jun 12-Aug 15-Sep Teroldego 13-May 20-Jun 25-Aug 26-Oct Tocai Fruilano 23-May 20-Jun - 27-Sep

Table 4: Yield and fruit composition of Vinifera wine grape varieties planted in OARDC-Wooster in 2016.

Pruning Pruning 100 Harvest Cluster Yield Yield Cl wt Crop Variety wt wt berry %SS pH %TA SS/TA Date #/vine (lbs/vine) (t/acre) (lb) load (lb/vine) (lb/ft) wt (g)

Chardonnay 16-Sep 31 8.8 4 0.28 2.7 0.45 3 176 22 3.08 8 27 Sauvignon 20-Sep 23 5.4 2 0.23 3.8 0.63 1 199 22 3.33 7.4 30 blanc

Regent 16-Sep 23 5.0 2 0.22 1.9 0.32 3 238 20 3.23 0.7 27

21 Table 5: Yield and fruit composition of Vinifera wine grape varieties planted in AARS-Kingsville in 2016.

Pruning Pruning Crop 100 Harvest Cluster Yield Yield Cl wt %SS pH %TA Variety wt wt load berry SS/TA Date #/vine (lbs/vine) (t/acre) (lb) *** **** ***** (lb/vine) (lb/ft)* ** wt (g) Albarino 31-Oct 40 6.99 2.82 0.17 2.89 0.48 2 116 21.4 3.10 1.09 20 Arneis 5-Oct 12 6.47 2.61 0.54 0.79 0.13 8 216 18.3 3.41 0.69 27 Cabernet franc 25-Oct 36 12.56 5.07 0.35 1.48 0.25 8 175 19.6 3.41 0.72 27 Chardonnay 5-Oct 29 10.32 4.16 0.36 2.37 0.40 4 169 20.8 3.47 0.74 28 Dolcetto 18-Oct 19 8.85 3.57 0.47 1.56 0.26 6 185 18.7 3.29 0.81 24 Durif 31-Oct 18 11.99 4.84 0.67 1.47 0.25 8 213 16.8 3.44 0.81 21 Gamay noir 5-Oct 36 15.48 6.25 0.43 1.75 0.29 9 248 17.6 3.36 0.72 25 Gruner Veltliner 27-Sep 38 22.37 9.03 0.58 1.16 0.19 19 206 17.3 3.27 0.66 26 Kerner 21-Sep 35 13.80 5.57 0.40 1.90 0.32 7 232 20.4 3.43 0.68 30 Moscato 29-Sep 12 5.28 2.13 0.42 1.42 0.24 4 266 18.1 3.34 0.82 22 Ortega 5-Oct 43 18.93 7.64 0.44 2.44 0.41 8 242 17.8 3.60 0.37 49 Petit Manseng 18-Nov 36 6.69 2.70 0.19 2.16 0.36 3 111 27.6 3.00 1.14 24 Pinot noir precoce 15-Sep 34 7.23 2.92 0.21 1.50 0.25 5 167 18.9 3.27 0.71 27 Pinot noir 22-Sep 25 6.83 2.76 0.27 1.10 0.18 6 165 18.2 3.36 0.81 23 Pinotage 14-Oct 27 10.92 4.41 0.40 1.33 0.22 8 188 21.3 3.26 0.77 28 Regent 7-Oct 37 12.46 5.03 0.34 1.28 0.21 10 307 19.5 3.46 0.67 29 Sangiovese 2-Nov 24 16.61 6.70 0.69 1.94 0.32 9 306 19.2 3.22 0.88 22 Sauvignon blanc 29-Sep 32 12.52 5.05 0.39 1.32 0.22 9 190 19.8 3.25 0.87 23 Sauvignon blanc 7 28-Sep 24 5.27 2.13 0.22 2.16 0.36 2 190 21.2 3.15 0.82 26 Sauvignon blanc 14 28-Sep 35 14.93 6.02 0.43 1.47 0.25 10 194 20.2 3.19 0.82 25 Sauvignon blanc 25 28-Sep 46 16.74 6.75 0.36 1.56 0.26 11 197 19.8 3.17 0.70 28 Sauvignon blanc 27 28-Sep 41 16.79 6.78 0.41 1.53 0.26 11 183 20.5 3.14 0.77 27 Sauvignon gris 28-Sep 39 9.64 3.89 0.24 1.35 0.23 7 184 19.4 3.14 0.84 23 Siegerrebe 15-Sep 39 19.42 7.84 0.50 2.06 0.34 9 258 16.1 3.26 0.54 30 Teroldego 25-Oct 13 7.32 2.95 0.56 1.76 0.29 4 227 20.4 3.31 0.92 22 Tocai friulano 27-Sep 22 6.69 2.70 0.31 1.83 0.31 4 172 19.1 3.16 0.80 24 *Ideal pruning weight range for vinifera: 0.2-0.4 lb/ft **Ideal crop load range for vinifera: 5-10 ***Ideal SS range: 18-24 Brix ****Ideal pH range: whites: 3.10-3.30, reds: 3.3-3.5 *****Ideal TA range: 0.6-0.8%

22 Table 6: Crown gall incidence in varieties grown at AARS-Kingsville. Data recorded 15 September 2015 and 20 October 2016.

% Crown gall incidence Variety 2015 2016 * Albarino 56 13 Arneis 75 29 Cabernet franc 78 35 Chardonnay 68 59 Dolcetto 74 38 Durif 50 29 Gamay noir 81 33 Gruner veltliner 63 29 Kerner 21 0 Muscato 7 Orgeta 36 0 Petit Manseng 41 25 Pinot noir 67 25 Pinot noir precoce 50 19 Pinotage 100 55 Refosco 38 Regent 33 10 Sangiovese 92 33 Sauvignon blanc 88 46 Sauvignon blanc 7 38 0 Sauvignon blanc 14 50 25 Sauvignon blanc 25 42 33 Sauvignon blanc 27 38 7 Sauvignon gris 78 53 Siegerrebe 78 10 Teroldego 68 33 Tocai Fruliano 75 38 * Crown gall visible on the graft union.

Table 7: Veraison petiole results of varieties grown in Kingsville during the 2016 season*.

Nitrogen Phosphorous Magnesium Potassium Calcium Sulfur Boron Iron Manganese Copper Zinc Aluminum Variety (%) (%) (%) (%) (%) (%) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm)

Muscato 0.91 0.23 0.45 3.97 1.02 0.182 19 54.4 161 8.4 111 63.2 Ortega 0.67 0.14 0.35 3.86 1.53 0.124 22.6 33.6 132 5.2 57.9 46.2 Pinotage 0.49 0.16 0.40 2.87 1.24 0.08 22.2 26.8 92.8 5.7 46.1 36.9 Regent 0.69 0.20 0.60 2.84 1.31 0.134 22.5 25 133 6.2 44.4 33.6 Regent -symptomatic 0.64 0.23 0.78 1.87 1.35 0.125 23.8 38.8 456 5.4 50.7 51.5 Regent – no symptoms 0.69 0.41 0.73 2.43 1.2 0.124 21.9 27.7 407 6.7 46.8 36.3 Sauvignon blanc 0.71 0.37 0.63 2.66 1.26 0.115 23.7 20.3 198 5.2 45.4 28.1 Teroldego 0.64 0.25 0.39 3.16 1.06 0.109 21.7 19.1 89.1 6.1 49.3 27.6 Tocai Fruliano 0.61 0.25 0.40 3.49 1.22 0.119 24.8 18.5 111 5.8 43.2 32.3 Ideal range 0.9-1.3 0.16-0.29 0.26-0.45 1.5-2.5 1.2-1.8 <0.1 25-50 31.50 31-150 5-15 30-50 No data *Petioles were collected from varieties that showed leaf symptoms in July 2016.

24 Variety trial new plantings grown at OARDC-Wooster October 17, 2016. Albarino Arneis

Dolcetto Fernao Pieres

Malvasia Merlot

Petite Manseng Pinotage

25 Regent Sauvignon blanc 1

Sauvignon blanc 7 Sauvignon blanc B14

Sauvignon blanc B18 Sauvignon blanc B26

Sauvignon blanc 27 Syrah

26 Touriga Brasileira Teroldego

Tocai Fruliano Trousseau

Verdejo Verdelho

Viosinho

27 Viticulture Production

Commercial Expansion of Varieties New to Ohio

Investigators: Imed Dami and Diane Kinney Cooperators: Caesar Creek, Laurentia, Meranda-Nixon, Stoney Ridge, Tarula, Quarry Hill, Kosicek, Old Mason, Vermillion Valley Trial Location: Commercial vineyards Project Type: Production Status: Final

Objective:

The OSU Viticulture-Enology Program has evaluated more than 40 varieties in the past 10 years. Evaluation consisted of quantifying the viticultural and enological performances and characterizing the pros and cons of these varieties grown under Ohio climates. From these trials, we identified more than two dozen varieties that performed well and thus have been recommended. Several educational programs (conferences, workshops, and field days) were presented to highlight these varieties with wine tasting. The purpose of this project was to further promote these varieties, maximize their exposure to growers and wine makers, and encourage their expansion. In 2015, the Viticulture Program engaged in a partnership with OGIC to promote planting varieties new to Ohio through a cost-share program.

Procedures:

 To maximize the success of the program and its impact and benefits, different types of grapes were utilized, i.e. cold hardy and cold sensitive, red and white varieties, long- and short-growing season (Table 1).

 In 2015, five (5) interested growers/vintners from the 3 main regions in Ohio (north, central, and south) agreed to participate in this project. In 2016, three (3) more vineyard and winery owners joined this project. In 2017, the Viticulture Program provided two (2) more varieties to one more grower/vintner. Dr. Dami provided recommendations on the best-suited varieties for each region and vineyard (Table 2).

 Due to unavailability from the nurseries, we were unable to purchase all of the varieties 1

28 of vines we ordered, or received limited quantities. Dr. Dami and his group collected cuttings to graft unavailable varieties (see list in Table 3).

Results:

 In March 2017, several varieties and clones were bench grafted in Dami’s lab. With the exception of few varieties the overall % graft take was as good as commercial standard or better (Table 3).

 Growers received specific varieties between 2-10 May 2016 depending upon the growers’ availability to plant upon receipt. Once the vines were received they were planted between 3-16 May 2016. In 2017, two varieties were supplied to Vermillion Valley vineyard (Table 2a).

 In late summer, Dami organized and visited participating vineyards (2015 & 2016) in the NE region with his group. The purpose of these visits was to ensure successful establishment of these varieties, data collection, and technical support on the specifics of growing each variety (see photos).

 Overall, most varieties established well and there was no or minimum vine loss. Young vines averaged 3 shoots per vine and 38 inches long (range 31-47)(Table 4).

 Since 2015, Dami provided technical assistance by phone and email and answer questions on how to grow these varieties.

Table 1a. Description of wine grape and rootstock varieties available for planting in 2017.

Variety Grape color Cold hardiness Clone Rootstock Plant material source

Fernao Pires White Cold tender FPS 01 3309 Grafted at OSU/OARDC 2016 Pinotage Red Cold tender FPS 01 101-14 Double A Vineyard nursery, NY

30 Table 1b. Description of wine grape and rootstock varieties available for planting in 2016.

Variety Grape color Cold hardiness Clone Rootstock Nursery source

Albarino White Cold tender FPS 01 101-14 Double A Vineyard, NY

Frontenac blanc White Very cold hardy own NE Vineyard Supply, VT

Gamay noir Red Moderately cold tender FPS 05 101-14 Grafted at OSU/OARDC 2015

Gamay noir Red Moderately cold tender FPS 05 3309 Grafted at OSU/OARDC 2015

Lagrein White Cold tender FPS 03 101-14 Cold storage Grey Creek Viticultural Malvasia White Moderately cold tender FPS 03 101-14 Services, CA NY 84.0101.04 white Moderately cold tender own 2015

Petite Pearl Red Very cold hardy own NE Vineyard Supply, VT

Pinotage Red Cold tender FPS 01 101-14 Double A Vineyard, NY

Regent Red Moderately cold tender 101-14 Grafted at OSU/OARDC 2015

Siegerrebe White Moderately cold tender FPS 02 101-14 Grafted at OSU/OARDC 2015

Tempranillo Red Cold tender FPS 03 101-14 Cold storage

Table 1c. Description of wine grape and rootstock varieties available for planting in 2015.

Variety Grape color Cold hardiness Clone Rootstock Nursery source

Aromella (NY 76.0844.24) White Cold hardy own Grafted Grapevine, NY

Brianna White Very cold hardy own Grafted Grapevine, NY

Pinotage Red Cold tender FPS 1 3309 Grafted Grapevine, NY

Sauvignon blanc White Cold tender FPS 27 Schwarzmann Novavine, CA

Teroldego Red Cold tender VCR 133 101-14 Novavine, CA

NY 81.0315.17 White Moderately tender 101-14 Double A Vineyards, NY Very cold hardy 101-14 (rootstock) rooted Vintage Nurseries, CA Very cold hardy C-3309 (rootstock) rooted Vintage Nurseries, CA

Sauvignon blanc White Cold tender FPS 14 101-14 Grey Creek Vit. Services, CA

Table 2a. Distribution of varieties and participating commercial growers/vintners in the Grape Variety Expansion Program in 2017.

Varieties and selection provided

Participant name Growing Region in Ohio Business name Location Fernao Pires 01/101-14 Pinotage 01/3309

Joe Juniper Northeast Vermillion Valley 25 40 Wakeman, OH 44889

Table 2b. Distribution of varieties and participating commercial growers/vintners in the Grape Variety Expansion Program in 2016.

Varieties and selection provided Growing Participant name Albarino Gamay noir Gamay noir Lagrein Malvasia Pinotage Siegerrebe Tempranillo Region in Business name Frontenac NY Petite Regent FPS FPS FPS FPS FPS FPS FPS FPS Ohio Location blanc 84 pearl /101-14 01/101-14 05/101-14 05/3309 03/101-14 03/101-14 01/101-14 02/101-14 03/101-14

Mac McLelland

Quarry Hill 14 41 50 Berlin Heights,

OH 44814 Northeast

Tony Kosicek Kosicek Vineyards 40 40 Harpersfield, OH 44041 Pam Stoltz Stoney Ridge Northwest 25 Bryon, OH 43506

Jeff Clark Central Old Mason 25 25 West Milton, OH 45383

Walter Borda

Caesar Creek 30 25 Winery Xenia,

OH 45385 Southern

Seth Meranda Meranda-Nixon 20 9 50 50 24 Winery Ripley, OH 45167

Table 2c. Distribution of varieties and participating commercial growers/vintners in the Grape Variety Expansion Program in 2015.

Varieties and selections provided Growing Participant name Region in Business name Sauv. blanc Sauv blanc Teroldego NY Ohio Location Aromella FPS 27/ Clone 1/ VCR133/ Brianna Pinotage 81.0315.17 (dormant) ** Scharzmann 101-14 101-14 (dormant) ** (dormant) ** (dormant) ** (potted)*** (dormant)** (potted)*** Leonard Blackie Northeast Laurentia 50 25 ~22 Madison, OH 44057

Phil & Pam Stoltz Northwest Stoney Ridge 50 50 Bryon, OH 43506

Walter Borda Central Caesar Creek 100 Xenia, OH 45385

Seth Meranda Meranda-Nixon 50 50 50 25 50 Ripley, OH 45167 Southern Aileen "Lou" Nebel Tarula 50 ~23 50 Clarksville, OH 45113

**Dormant: Bare rooted vines kept in cold storage until ready to plant ***Potted: Green plants ready to be planted immediately.

35 Table 3. Varieties grafted at OARDC-Wooster, April 2017.

# Dead # Grafts % Graft Variety Clone Rootstock # Grafted ( No Callus-No with Take Growth) Callus

Cab franc (W) FPS 11 101-14 10 2 8 80 Dolcetto FPS 02 101-14 30 2 28 93 Durif (K) FPS 03 101-14 10 1 9 90 Kerner (K) FPS 01 101-14 10 3 7 70 Primitivo FPS 03 101-14 30 5 25 83 Primitivo FPS 05 101-14 25 4 21 84 Primitivo FPS 06 101-14 25 10 15 60 Sangiovese (K) FPS 14 101-14 10 4 6 60 *Canes were collected from Wooster (W) and Kingsville (K)

36 Table 4. Varieties grafted at OARDC-Wooster, March 2016.

# Dead # # Grafts Graft Variety Clone Rootstock (no callus- Grafted with callus take (%) no growth)

Arneis (W) FPS 01 3309 10 4 6 60 Arneis (W) FPS 01 101-14 30 10 20 67 Auxerrois (K) 45? 101-14 16 2 14 88 Cab franc (K) FPS 01 101-14 5 0 5 100 Dolcetto (W) FPS 01 101-14 29 10 20 69 Fernao Pires (W) FPS 1 3309 42 3 39 93 Gruner Veltliner (K) 101-14 5 0 5 100 Ortega (K) 101-14 5 2 3 60 Petite Manseng (K) 101-14 25 2 20 80 Pinot noir (K) 113 3309 10 3 7 70 Pinot noir (K) Pommard 3309 10 1 9 90 Sauv B (W) FPS 18 3309 10 3 7 70 Sauv B (W) FPS 18 101-14 30 0 30 100 Sauv B (W) FPS 26 101-14 32 3 29 91 Sauv B (W) 7 101-14 30 8 22 73 Sauv gris (K) FPS 01 101-14 20 1 19 95 Teroldegao (W) FPS 02 101-14 52 9 43 83 Teroldego (W) FPS 06.1 101-14 30 4 26 87 Tocai Friulano (W) FPS 01 101-14 30 14 16 53 Touriga Brasiliera (W) FPS 01 3309 33 4 30 91 Trousseau (W) FPS 10.1 3309 5 3 2 40 Trousseau (W) FPS 10.1 101-14 29 1 28 97 Verdejo (W) FPS 1.1 3309 40 1 39 98 Verdelho (W) FPS 11.1 3309 41 3 38 93 Viosinho (W) FPS 1.1 101-14 30 2 29 94 *Canes were collected from Wooster (W) and Kingsville (K).

37 Table 4. Growth evaluation of varieties planted in collaborating vineyards in 2016.

Shoot length Vineyard Variety Clone Rootstock Shoots/vine (in)

Kosicek Vineyards* Regent 101-14 3 31

Siegerrebe FPS 02 101-14 4 33

Quarry Hill ** Gamay noir FPS 05 101-14 2 39 Gamay noir FPS 05 3309

Pinotage FPS 01 101-14 2 47 *Kosicek: All plants clean with excellent disease/insect and weed control. No losses of vines. **Quarry Hill: Good growth/clean foliage/good leaf color/staked but not trained/some Japanese beetle damage inside grow tubes. Did not keep two rootstocks with Gamay noir separated when planted and unknown where each are planted for certain.

Kosicek Vineyards – August 10, 2016

Quarry Hill – August 10, 2016

Laurentia Winery – August 10, 2016

39 Quarry Hill—September 6, 2017

Gamay noir 2nd leaf

Pinotage 2nd leaf

40 Viticulture Extension & Outreach

The following section describes the Extension and Outreach activities and accomplishments by the Viticulture group during the period from July 1, 2016 to June 30, 2017.

OGEN and Fruit Maturity Updates: Articles authored and contributed by Dr. Dami and Diane Kinney:

• Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 16 August. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 22 August. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 31 August. • Dami, I., D. Kinney. 2016. Vine & Wine News @ “Buckeye appellation”. OGEN. 31 August. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 6-7 September. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 12-13 September. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 19 September. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 27 September. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 3 October. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 6 October. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 10 October. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 17 October. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 24 October. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 26 October. • Dami, I., D. Kinney. 2016. 2016 Fruit Maturity OSU – Wooster and Kingsville. 7 November. • Dami, I., D. Kinney. 2017. Vine & Wine News @ “Buckeye appellation”. OGEN. 31 January. • Dami, I., D. Kinney. 2017. Grapevine Cold Hardiness at OSU Research Vineyard. OGEN. 3 March. • Dami, I., D. Kinney. 2017. Vine & Wine News @ “Buckeye appellation”. OGEN. 31 March. • D. Kinney, Dami, I. 2017. Vine & Wine News @ “Buckeye appellation”. OGEN. 28 April. • D. Kinney, Dami, I. 2017. OARDC – Wooster April 2017 Vineyard Update. OGEN. 28 April. • Dami, I., D. Kinney. 2017. Last Week’s Frost Damage Update Special. OGEN. 16 May. • D. Kinney, Dami, I. 2017. Vineyard Update from OARDC in Wooster. OGEN. 31 May. • D. Kinney, Dami, I. 2017. Vine & Wine News @ “Buckeye appellation”. OGEN. 31 May. • D. Kinney, Dami, I. 2017. Vineyard Update from OARDC in Wooster. OGEN. 30 June. • D. Kinney, Dami, I. 2017. Vine & Wine News @ “Buckeye appellation”. OGEN. 30 June.

41 Ohio Grape & Wine Conference:

Dr. Dami and Andy Kirk, AARS Kingsville, gave presentations that provided updates on research projects funded by OGIC.

1. Dr. Dami presented “Grapevine Recovery from Cold Damage: What We Have Learned in the Past 3 years”.

2. Andy Kirk presented “OSU Variety Trial: 2016 Season Observations”.

Dr. Tim Martinson was the featured viticulture speaker. Conference audience at the general session. Ken Schuchter of Valley Vineyards, accepting the Winemaker of the Year Award and Andy Kirk, discussing the 2016 Growing Year at AARS Kingsville

42 Industry Field Day and Workshops:

Dr. Dami and his group participated in statewide workshops and field days and presented research updates on viticulture projects.

1. 11 August: 2016 Ohio Grape and Wine Day. Held at the Ashtabula Agricultural Research Station. MS candidate, Thomas Todaro, gave a talk about Trunk Rehabilitation Techniques and Ph. D candidate, Jaclyn Fiola, gave a talk about the Soil Profile at the Ashtabula Agricultural Research Station. Approximately 50 in attendance.

Dr. Dami and Diane Kinney updated the industry on the work performed this past season by the viticulture program as well as on recent cold weather events at three Post Fermentation Wine Quality Control Workshops.

2. 20 Dec: Post Fermentation Wine Quality Control Workshop. Held at Harpersfield Vineyard, Geneva OH. Approximately 40 in attendance.

3. 10 Jan: Post Fermentation Wine Quality Control Workshop. Held at Olde Schoolhouse Vineyard and Winery, Eaton, OH. Approximately 25 in attendance.

4. 17 Jan: Post Fermentation Wine Quality Control Workshop. Held at Knotty Vines Vineyard and Winery, Wauseon, OH. Approximately 12 in attendance.

5. 18 Apr: 2017 Pinot Gris Grape & Wine Production School. Held at Virant Family Winery, Geneva, Ohio. Dr. Dami presented an Overview of Pinot Gris Viticulture Research at OSU. Approximately 30 in attendance.

6. 18 Apr: 2017 Pinot Gris Grape & Wine Production School. Held at Virant Family winery, Geneva, Ohio. Thomas Todaro presented Best Viticulture Practices for Pinot Gris. Approximately 30 in attendance.

44 “Buckeye Appellation” Website:

http://ohiograpeweb.cfaes.ohio-state.edu

• Many updates to the website were made throughout the year in addition to our monthly OGEN newsletters. Updates on frost events in April were also posted timely and shared with growers in Ohio.

• 2 New educational You-Tube videos on “Pruning Grapevines - VSP” and “Grapevine Canopy Management” were produced and posted on the website.

• A total of 121 postings were made on Buckeye Appellation broken down as follows:

Buckeye Appellation website updates by quarter during the Fiscal Year 2017.

Website Update 1st Qtr 2nd Qtr 3rd Qtr 4th Qtr Sub-total OGEN 4 4 4 5 17 TGE 15 5 4 24 Events & News 7 6 7 12 32 Videos 2 2 Fruit Maturity 7 7 14 Other 2 10 5 15 32 Sub-total 35 32 20 34 121

Website Statistics:

Google Analytics of Buckeye Appellation for reporting period 1 Jul 16 – 30 Jun 17 (Fig.1-2): o 6,970 session views, an increase by 22% from previous year o 4,787 users, an increase by 24% from previous year o 23,549 page views, an increase by 35% from previous year

45 Fig.1 Website Demographics 1 July 16 - 30 Jun 17

1% 1% 1% 1% 2% 2% 12%

4% 7%

Columbus Wooster Cincinnati (not set) Canton Cleveland Dublin Detroit Chicago Ashtabula

Fig. 2

46 New additions to Buckeye Appellation in 2016-2017

2 new training videos: Pruning Grapevines – VSP and Grapevine Canopy Management

Industry Meetings: Dr. Dami participated at industry committee meetings to provide technical advice and updates on viticulture research and Extension activities.

1. 8 September 2016: OGWC organizing committee meeting at OARDC, Wooster. 2. 2 November 2016: OGIC Research Sub-Committee meeting. ODA, Reynoldsburg. 3. 2 November: OGIC Business Meeting. ODA, Reynoldsburg. 4. 24 May 2017: OGIC Full Committee meeting. Columbus. 5. 24 May 2017: Industry Reception at the State House. Columbus.

Professional Meetings(out-of-state): Dr. Dami attended the following meetings to present research findings and represent Ohio and the eastern US grape and wine industry.

17-18 November 2016. USDA-NE1020 Project Meeting. Dami presented a progress report on the variety evaluation trials in Ohio. Burlington, Vermont.

47 11 January 2017. Impact of Crop Load & Canopy Management on Fruit/Wine Quality & Cold Hardiness: Chambourcin Study. Invited speaker at the Indiana Horticulture Congress. Indianapolis, Indiana.

12 January 2017. Managing Winter Damage: Lessons Learned. Invited speaker at the Indiana Horticulture Congress. Indianapolis, Indiana.

3-6 April 2017: National Viticulture Extension Leadership Conference. Dami presented a report about the Ohio industry and research and extension activities. Oakville, California.

Publications in Scientific Journals and Trade Magazines in 2016-2017: Reprints of full articles will be provided upon request.

Todaro, T.M., and I.E. Dami. 2017. Cane Morphology and Anatomy Influence Freezing Tolerance in Vitis vinifera Cabernet franc. Int’l J. Fruit Sci. doi.org/10.1080/15538362.2017.1330667.

Dami, I. 2017. Determining the Best Cold Hardiness Measurement. Wines & Vines (trade magazine). January: 164-167.

Zhao, L., A.M. Chanon, N. Chattopadhyay, I. Dami, J. Blakeslee. 2016. Quantification of Carbohydrates in Grape Tissues Using Capillary Zone Electrophoresis. Frontiers in Plant Science, section Technical Advances in Plant Science.(doi:10.3389/fpls.2016.00818).

Mohseni-Moghadam, M., S.Wolfe, I.Dami, D. Doohan. 2016. Response of Wine Grape (Vitis vinifera L.) Cultivars to Simulated Drift Rates of 2,4-D and Dicamba, and with/without Glyphosate”. Weed Technology.(doi:10.1614/WT-D-15-00106.1.)

Dami, E.I., S. Li, and Y. Zhang. 2016. Evaluation of Primary Bud Freezing Tolerance of Twenty- three Winegrape Cultivars New to the Eastern United States. Am. J. Enol. Vitic. Vol. 67 (2): 139-145 (doi:10.5344/ajev.2015.15047.)

48 Student Training & Accomplishments

Graduate Student Training & Research:

Dr. Dami’s two (2) graduate students:

1. Jaclyn Fiola, PhD student began her research in August 2016. Her project is titled: “The Terroir of Ohio Viticulture: Grapevine-Soil Interactions, Environmental Sustainability, and Cold Hardiness of Growing Grapes in Ohio.” 2. Thomas Todaro, MS, completed his research thesis titled: “Evaluating Cultural Practices for Recovery from Cold Damage in Grapevines.”

Undergraduate Student Training:

In 2016-2017, Dr. Dami trained two (2) summer students: Brevin Shearer and Sarah Kline. Sarah is a sophomore at Ohio University and completed an internship with the OSU/OARDC ORIP program while Brevin is a sophomore at Bowling Green University. Both students continued to learn viticulture through various cultural practices in the vineyard and greenhouses.

49 Honors & Awards

Jaclyn Fiola, Ph. D student in the Viticulture Program received four (4) national scholarships.

1. American Society for Enology and Viticulture Michael Vail Scholarship: The American Society for Enology and Viticulture annually awards competitive scholarships to the best students, across the country, pursuing a degree in enology, viticulture, or in a curriculum emphasizing a science basic to the wine and grape industry.

2. American Society for Enology and Viticulture Eastern Section Scholarship (ASEV-ES): For students working toward careers in viticulture and enology. Also includes complimentary registration and room expenses at the annual ASEV-ES conference to be held in Charlottesville, VA.

3. Phi Kappa Phi Love of Learning Travel Award : Love of Learning Awards help fund post- baccalaureate professional development for active Phi Kappa Phi members to include (but not be limited to): Graduate or professional studies, doctoral dissertations, continuing education, career development, travel related to teaching/research/learning, etc.

4. American Wine Society Educational Foundation: Carroll County, MD AWS Chapter Scholarship / In Honor of Becky and Dean Wilson: The AWSEF annually awards academic scholarships to support university graduate students pursuing an academic career in enology, viticulture, or health aspects of wine based on academic excellence and genuine interest in pursuing careers in wine-related fields.

Thomas Todaro, an MS graduate from the OSU Viticulture Program, has recently accepted an Extension educator position at Michigan State University to serve the wine and grape industry in northwest Michigan (read more at this link: http://msue.anr.msu.edu/news/new_wine_and_grape_educator_hired_in_northwest_michigan ). While at OSU, Thomas’s research focus has spanned cultural practices to improve fruit and wine quality, increased freezing tolerance of bud and cane tissues, and improved efficiency in vine recovery following winter damage. His thesis titled “Evaluating Cultural Practices for Recovery from Cold Damage in Grapevines” involved managing winter-damaged vines after the 2014-2015 polar vortex events. He has recently published a research paper titled “Cane Morphology and Anatomy Influence Freezing Tolerance in Vitis vinifera Cabernet franc” in the International Journal of Fruit Science (online access: http://www.tandfonline.com/doi/pdf/10.1080/15538362.2017.1330667?needAccess=true).

Thomas has also been involved in extension and outreach activities in the viticulture program and has recently completed an educational video on grapevine pruning posted on You-Tube (https://ohiograpeweb.cfaes.ohio-state.edu/video.) 60

50 Appendix

1. Dami, I. 2017. Determining the Best Cold Hardiness Measurement. Wines & Vines. January: 164-167.

2. Todaro, T. and Dami, I. 2017. Cane Morphology and Anatomy Influence Freezing Tolerance in Vitis vinifera Cabernet franc. International Journal of Fruit Science. 16 January: 1-16.

51 GRAPEGROWING WINE EAST Determining the Best Cold Hardiness Measurement Nearly two-dozen grape varieties tested for ability to withstand below-freezing temperatures A variety trial plot (shown here before the polar By Imed Dami vortex of 2014) helped researchers understand each variety’s cold tolerance.

rapes contribute more than Therefore, the limitation imposed by the searchers also investigated whether there are $5 billion per year to the sensitivity of the vinifera species has an im- better ways to estimate the CH of vines. economy of the eastern pact on the sustainable growth of the indus- Buds were collected from each variety bi- United States, and the grape try, and it is critical for growers to know the weekly between September and March for three and wine industries have cold hardiness (CH) of the newly introduced dormant seasons (2011-14) and placed in a been expanding rapidly in varieties, in addition to the standard viticul- freeze chamber. The freeze chamber was set up Gthose regions. However, the sustainability of tural and enological characteristics. Sub- indoors to conduct freezing tests that would profitable yet cold-sensitive cultivars is limited freezing temperatures below -20° C (-4° F), simulate cold damage in the vineyard. Cold by climatic constraints, primarily lethal freez- often damage V. vinifera, which is mostly hardiness was determined by thermal analysis ing temperatures that can drop well below adapted to a Mediterranean-type climate. and expressed by the lethal temperature that

0° F. The severe economic losses that result Nonetheless, information about the CH of kills 50% of the bud population, or LT50. from freezing injury continue to be a major the newly introduced vinifera varieties has We evaluated three methods to express cold setback for the continuous growth of the not been available. hardiness: grape and wine industries in this region. 1) Standard method: computing mid-winter In 2014, the polar vortex caused temperatures Ohio’s cold-hardiness study hardiness based on a single and lowest to drop to critical levels for grape survival and The purpose of the study at the Ohio Agricultural LT 50 value; resulted in widespread damage and crop losses Research and Development Center in Wooster 2) Modified standard method: computing across the Midwest and eastern United States. was to determine the cold hardiness of 23 variet- mid-winter hardiness based on multiple Ohio experienced the worst damage and crop loss ies of recently introduced V. vinifera grapes so lowest LT values; in 20 years (valued at $12 million). This problem that grapegrowers and nurseries would have a 50 was exacerbated with whole-vine loss of cold- better understanding of the ability of those variet- 3) Annual freezing tolerance (AFT, or an- sensitive species V. vinifera, which have dominated ies to survive the harsh winter conditions in the nual cold hardiness): computing LT50 new plantings in the past 15 years in Ohio. Midwest and northeastern United States. Re- not only during mid-winter, but also during fall acclimation and spring KEY POINTS deacclimation. The Ohio State University’s OARDC tested the cold hardiness of 23 varieties newly introduced in Mid- west and northeastern vineyards using three methods of testing: the standard method of indexing Cold hardiness mid-winter bud cold hardiness (LT ); a modified standard method based on regression analysis; and 50 of 23 varieties researchers developed a new cold hardiness index, the relative annual freezing tolerance (RAFT), As expected, all 23 varieties behaved similarly which compares annual freezing tolerances of these varieties with that of a benchmark variety. and followed the typical U-shaped pattern of These 23 varieties can be grouped into two distinct groups of most cold hardy (Gamay Noir, Chardon- bud cold hardiness, which consists of three nay, Pinotage, Regent and Rotberger) and most cold sensitive (Barbera, Durif, Lagrein, Sangiovese, stages: fall cold acclimation (September to Syrah, Tempranilllo and Teroldego). The remaining 11 varieties fall in the gray area, and their CH may December), followed by maximum hardiness shift one way or another depending on other factors such as weather and cultural practices in mid-winter (January to February) and deacclimation in late winter and early spring. The findings of this study provide research-based information for nurseries and on cold hardiness of However, there were differences of cold new varieties they sell. They will also guide growers making decisions on suitable varieties for sites hardiness among varieties. Gamay Noir, Rot- where winter damage is a concern. berger, Pinotage and Regent were generally 52 164 WINES&VINES January 2017 WINE EAST GRAPEGROWING among the most cold-hardy variet- a given variety’s cold hardiness and COLD HARDINESS FOR THREE SEASONS ies with the lowest LT50 values, has been reported as such by re- while Tempranillo, Lagrein, Bar- search institutions in several states 0 bera and Durif were among the conducting this type of work in the most cold-sensitive varieties with past 30 years. In Ohio, we found Gamay Noir Tempranillo the highest LT50 values. that mid-winter cold hardiness var- Also, this study showed that not ied between LT = -18.3° C Dolcetto 50 -5 all varieties acclimated, de-accli- (-0.9° F) and LT50 = -24.8° C (-12.6° mated or reached maximum hardi- F). “Cold Hardiness Based on Stan- ness at the same time and same dard Method” shows that Gamay level. “Cold Hardiness for Three Noir was the most cold-hardy vari- -10 Seasons” shows three varieties to ety, whereas Tempranillo was the illustrate this finding. Gamay Noir most cold sensitive in this study. (°C) (°C) was the most cold-hardy variety We also found that the standard 50 (lowest LT in mid-winter) and method has a few drawbacks: a) LT 50 -15 was the quickest (steepest slope) the lowest LT50 in mid-winter is to cold acclimate in the fall. Tem- generally based on a single LT50 pranillo was the most cold sensitive measurement; b) not all varieties (highest LT in mid-winter) and reached their maximum cold hardi- 50 -20 was the quickest to deacclimate in ness on the same date; and c) wide late winter. Dolcetto acclimated the variability of LT50 within each cul- slowest in the fall and reached tivar made it difficult to distinguish maximum cold hardiness later cold hardiness between two variet- -25 than Gamay and Tempranillo. ies if the difference between their 252 287 312 341 3 46 82 LT was less than 3° C (5.4° F). 50 Day of Year Methods of assessing During the polar vortex in cold hardiness January and February 2014, the Cold hardiness changes of Gamay Noir, Dolcetto and Tempranillo in the Standard method: Mid-winter bud research vineyard in Wooster ex- Wooster research vineyard by day of year for three seasons. Plot points cold hardiness (LT ) is the most perienced successive low tempera- 50 represent LT50 (lethal temperature that kills 50% population) collected for three commonly used index to estimate tures that dropped below the seasons. Note the U-shaped trend lines of cold hardiness in the three varieties.

MATERIALS AND METHODS

Varieties tested: Vitis vinifera—Arneis, Barbera, Cabernet Franc, Cabernet Sau- vignon, Carmenère, Chardonnay, Dol- cetto, Durif, Gamay Noir, Kerner, Lagrein, Malbec, Malvasia Bianca, Merlot, Pino- tage, Rotberger, Sangiovese, Sauvignon Blanc, Siegerrebe, Syrah, Tempranillo, Teroldego; and Vitis sp.—Regent (a Ger- man cross of Diana and Chambourcin)

Rootstock: 101-14 Mgt. (V. riparia × V. rupestris)

Location: OSU Research Vineyard at OARDC in Wooster, Ohio (lat. 40°44’16” N; long. 81°54’12” W)

Elevation: 1,165 feet above sea level

USDA Plant Hardiness Zone: Zone 6a (-10° F to -5° F).

Spacing: 9 feet x 6 feet (row x vine)

Training: Bilateral low cordon (40-inch height) with vertical shoot position (VSP)

Pruning: Spur pruning to 30 buds per vine (two to three buds per spur)

53 Janaury 2017 WINES&VINES 165 GRAPEGROWING WINE EAST

COLD HARDINESS BASED ON STANDARD METHOD -14

-16

-18

-20

(°C) (°C) -22 50 LT -24

-26

-28

-30

Syrah Durif Arneis Regent Lagrein Merlot Dolcetto Malvasia Barbera Pinotage Rotberger Teroldego Gamay Noir Carmenère Siegerrebe Sangiovese Tempranillo

Sauvignon Blanc Cabernet Sauvignon Cultivar

Cold hardiness is calculated based on the lowest LT50 of each variety in mid-winter. ANNUAL FREEZING TOLERANCE FOR CALCULATING COLD HARDINESS -13

-14

-15

-16

-17 AFT (°C) AFT (°C) -18

-19

-20

Syrah Durif Regent Arneis Merlot Kerner Malbec Dolcetto Lagrein Barbera Pinotage Teroldego Rotberger Siegerrebe Carmenère Gamay Noir Chardonnay Sangiovese Tempranillo Cabernet Franc Malvasia Bianca Sauvignon Blanc Cabernet Sauvignon Cultivar

The annual freezing tolerance (AFT) is based on computing LT50 throughout the dormant season.

- BECOPAD - YEAST & ENZYME S

S WineDoc® EQUIPMENT PAD CRUSH - WINERY CONSULTING

• Winery Design • Business Plans • Building & Floor Plans—New or Expansion • Equipment & Lab Specs • Assistance for Winemaking

(859) 533-8759

[email protected]

HOSE - OAK ALTERNATIVE

www.winedoc.com STERILE FILTRATION - WINE - FILTRATION STERILE Y R

54 166 WINES&VINES January 2017 WINE EAST GRAPEGROWING critical temperature of -20° C (-4° F) five times RELATIVE ANNUAL FREEZING TOLERANCE (-20.1° C [-4.2° F] to -24.5° C [-12.1° F]). All 23 varieties sustained trunk damage, with the 3 exception of Regent. The extent of whole-vine damage was assessed in late summer 2014, and vine death was recorded. 2 In general, variety vine mortality corresponded to the computed LT50. For example, 1

Tempranillo, with the highest LT50 (most cold sensitive), sustained the highest vine mortal- Merlot Gamay Noir Pinotage Rotberger Chardonnay Regent Malvasi Siegerrebe Carmenère Cabernet Sauvignon Sauvignon Blanc Cabernet Franc Malbec Arneis Dolcetto Kerner ity (100%), while Gamay Noir, with the lowest 0 Durif RAFT (˚C) LT 50 (most cold hardy), sustained the least Syrah Lagrein Barbera

vine mortality (17%). Therefore, the 2014 -1 Teroldego Tempranillo winter damage sustained in the vineyard co- Sangiovese incidently confirmed our cold hardiness de- -2 termination in the laboratory. Modified standard method: This method based on regression analysis was explored to -3 alleviate the limitation of the standard method. Cultivar It proved superior to the standard method since Annual cold hardiness is shown relative to that of Merlot, computed by subtracting the annual mean LT50 of it distinguished the CH between two varieties each variety from that of Merlot (baseline 0º C). at 2° C (3.6° F). However, it was not possible to obtain estimates for all varieties tested since trary measure of CH, which will vary with time of -2.5° C, meaning Gamay is more hardy than more LT50 observations were needed. and space. In other words, one cannot extrapo- Merlot by ~2.5° C. However, Barbera has a RAFT

A new index–the AFT: The annual freezing late LT50 published values determined in one of ~1.5° C, meaning Barbera is less cold hardy tolerance (AFT) or annual cold hardiness con- location (e.g., in New York) to equate the ac- than Merlot. In other words, if a region is known sisted of averaging LT50 throughout the dor- tual LT50 in another region (e.g., in Missouri). to have Merlot as a borderline variety for winter mant season. AFT has several advantages over This may be common knowledge within the survival, then a grower should not even think the standard method currently used by nurser- research community, but it is frequently misin- about planting Barbera in the same region. ies, growers and researchers. First, AFT pro- terpreted by vineyard owners and nurseries. Finally, among the three methods, AFT provides an estimate of CH across all stages of cold To overcome this issue, we propose to com- duced the best prediction of whole-vine CH. acclimation (i.e., autumn acclimation, mid- pare the CH of varieties to a standard or bench- winter maximum hardiness and spring deac- mark variety grown in the same location. We Imed Dami is professor of viticulture in the Department climation). As a result, the AFT had the least call the new index the relative annual freezing of Horticulture and Crop Science, Ohio Agricultural Research and Development Center, The Ohio State LT 50 variability, and differences between two tolerance, or RAFT. Merlot was selected since varieties were detected at the 1° C (~ 2° F) it is a common variety grown in different re- University, in Wooster, Ohio. level (see “Annual Freezing Tolerance for Cal- gions worldwide and has mid-range CH. The author thanks project participants Dr. Yi Zhang and culating Cold Hardiness”). Second, the stan- The figure above illustrates RAFT with nega- Shouxin Li and the USDA-NIFA (agreement No. 2010- dard method provides an LT50 of a given variety tive numbers indicating more cold-hardy varieties 51181-21599), Ohio Grape Industries Program and OSU determined on a specific date and location. and positive numbers more cold-sensitive variet- Department of Horticulture and Crop Science for their EasternWineLab_Mar09.qxp 1/22/09 9:47 AM Page 1 Hence, this absolute value provides an arbi- ies than Merlot. For example, Gamay has a RAFT financial support.

EASTERN WINE LABS GREEN GRAPE HOE Serving the

Analytical needs of Basic Hoe comes with a East Coast Wineries Hillup and a Takeaway Blade. Additional attachments include .3 Tooth Cultivator, WWW.EASTERNWINELABS.COM Undercutter Blade, Rotary head, " NEW " Rolling Ph 609-859-4302 Cell 609-668-2854 Cultivator and "Vine Auger". [email protected] AOAC Member

The Green Hoe Company, Inc. 6645 West Main Road, Portland, NY 14769 PHONE (716) 792-9433 FAX (716) 792-9434 WWW.GREENHOECOMPANY.COM 55 Janaury 2017 WINES&VINES 167 INTERNATIONAL JOURNAL OF FRUIT SCIENCE https://doi.org/10.1080/15538362.2017.1330667

Cane Morphology and Anatomy Influence Freezing Tolerance in Vitis vinifera Cabernet franc Thomas M. Todaro and Imed E. Dami Department of Horticulture and Crop Science, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio, USA

ABSTRACT KEYWORDS In 2014 and 2015, Ohio vineyards were exposed to multiple Primary bud; phloem; xylem; freeze events of –20 °C or lower, resulting in vine dieback, i.e., soluble sugars; trunk complete damage of above ground parts in Vitis vinifera. replacement Grapevines that sustained dieback were rehabilitated for trunk replacement by training 1-year-old shoots with two distinct morphologies, based on internode diameter of large (L) and normal (N). This study evaluated the impact of cane morphology (L and N) in V. vinifera Cabernet franc on freezing tolerance (FT) of bud, phloem, and xylem tissues in relation to their respective anatomical structures and carbohydrate concentrations. Compared to N canes (7–9-mm diameter), L canes (10–15 mm) in Cabernet franc were considered vigorous and had the following morphological characteristics: long and heavy, with long and wide internode, and presence of numerous laterals. Furthermore, cane anatomy was also different with L canes having a significantly higher number of vascular transport units, xylem vessels, and phloem fibers than those in N canes. Freezing tolerance of buds and phloem was also different between the two cane types, with L canes being more cold sensitive than N canes, especially during fall acclimation and late-winter deacclimation. Sugar concentrations, however, were not different between L and N canes. These results suggest that cane morphology and anatomy play a significant role in affecting FT and the large and abundant anatomical structures of phloem and xylem contributed to the reduced FT of these tissues. In all practicality, this study suggests the best cultural practice for trunk replacement, and vine recovery should include the removal of the undesirable vigorous and cold sensitive canes during pruning.

Introduction Ohio has a thriving grape and wine industry that ranks among the top 10 states in the United States in grape acreage, grape production, and number of wineries. However, the sustainability and expansion of this industry is limited by climatic constraints, primarily seasonal freezing temperatures. Freezing damage is the leading environmental stress that causes crop loss to the grape industry in Ohio

CONTACT Imed E. Dami [email protected] Department of Horticulture and Crop Science, The Ohio State University, 1680 Medison Ave., Wooster, OH 44691. Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/wsfr. © 2017 Taylor & Francis

56 2 T. M. TODARO AND I. E. DAMI and surrounding states (Zabadal et al., 2007). Ohio grape growers experienced major consecutive freezing damage episodes over the last 10 years with unprece- dented crop and vine losses valued at $12 million following the “polar vortex” event in 2014 (Dami et al., 2014;DamiandLewis,2014). In order to mitigate freezing damage in grapevines, various protection methods have been developed and implemented prior to, during, or after a freezing event, with the purpose of improving the freezing tolerance (FT) or recovery of grapevines (Howell, 1988; Poling, 2008; Pool and Howard, 1985). Managing grapevines after winter damage is an important practice to accelerate vine recovery and resume normal production in subsequent years. Trunk renewal, by retraining 1-year-old canes, is a key cultural practice following freezing injury. In Jan. and Feb. 2014, there were five freezing events of air temperature below – 20 °C (–20.1 to –31 °C) at The Ohio State University research vineyard. These extreme and repeated sub-freezing events resulted in dieback, i.e., complete damage (100%) of above-ground vine parts, including buds, canes, and trunks of all V. vinifera cultivars (Dami et al., 2016). Only buds at the base of trunks and protected by soil hilling survived (Figure 1A and B). The practice of soil hilling (covering the graft union with soil) protects the buds at the base of the scion for trunk renewal (Pool and Howard, 1985; Zabadal et al., 2007). New shoots matured to canes, during the 2014 growing season, were again exposed to nine freezing events of air temperature below –20 °C (–20.3 to –22.8 °C) in Jan. and Feb. 2015. As a result, 1-year-old buds and canes were damaged except for the basal buds protected by soil hilling. These back-to-back damaging events presented an opportunity to conduct a trunk renewal study to provide research- based guidelines on optimum cultural practices for vine recovery. The purpose of this research was to evaluate FT or cold hardiness, carbohydrate metabolism, and internal structures (anatomy) in dormant grapevine canes with different morphology (cane size). The central hypothesis was that cane FT was impacted by cane morphology, anatomy (internal structures), and carbohydrate (sugar) concentration. The central hypothesis of this research was tested by pursuing the following specific research objectives: (1) Determine morphological characteristics of cane with different sizes, based on cane diameter. (2) Evaluate the internal (anatomical) structures, FT, and carbohydrates of cane vascular tissues at various stages of cold acclimation in relation to cane morphology.

Materials and methods Plant material and treatments ThisstudywasconductedattheOhioStateUniversityresearchvineyardin Wooster (40.7384 latitude and –81.9032 longitude, elevation, 355 m asl; soil series, Riddles silt loams) in northeast Ohio (USDA Plant Hardiness Zone 6a [–23.3 to – 20.6 °C]; ARS-USDA 2012). Vitis vinifera Cabernet franc clone FPS11 grafted

57 INTERNATIONAL JOURNAL OF FRUIT SCIENCE 3

A B

C D

L N

Figure 1. Trunk renewal of severely freeze-damaged Cabernet franc grapevines. (A) Vine dieback (100% bud, cane, cordon, and trunk damage) with new shoots emerging in the spring. (B) Fan-trained shoots in mid-summer. Note dead trunks and cordons were removed. (C) Mature shoots (canes) in the fall with two distinct internode sizes, medium or normal (N) and large (L) or bull. (D) Two-node cuttings showing cane size based on internode diameters and compared to pencil size.

onto V. riparia × V. rupestris 101-14 were planted in 2010 in a north-south orientation and vines were spaced 1.8 m × 2.7 m (vine × row). Grapevines were trained to bilateral cordons (1.05-m high) with vertical shoot positioning (also known as VSP) during the growing season (Figure 1A), and spur pruned to 15 buds per meter of cordon during the dormant season. Following the freeze events in 2014 and 2015 and vine dieback, newly emerged shoots at the base of trunks and above the graft union were trained to a fan system (Figure 1B; Zabadal et al., 2007). These shoots had primarily two sizes, large (L) and normal (N). This study used 25 grapevines with L and N shoots/canes for trunk replacement. On 6 Aug. 2015, shoot/cane size was determined with a caliper (Mitutoyo-Digimatic Caliper, Kawasaki, Japan) by measuring the diameter of internodes 2 (cane tissue between node 2 and 3) and 3 (cane tissue between node 3 and 4), which averaged 13 mm (10–15 mm) in L and 8 mm (7–9 mm) in N (Figure 1C and D).

Weather conditions during the study Hourly maximum and minimum temperatures (°C) were recorded throughout the duration of the study using a temperature logger (Watchdog Model #A110,

58 4 T. M. TODARO AND I. E. DAMI

Spectrum Technologies, Aurora, IL, USA) installed at the north end of the vineyard. Temperature data were downloaded monthly to a laptop computer, and both the fall frost date (first occurrence of temperature below 0 °C in the fall) and total number of frost-free days (FFD; number of successive days with a minimum daily temperature at or above 0 °C) were determined from the temperature logger data. Growing degree-days (GDD in °C) represents the cumulative heat units during the growing season, and was calculated by adding the daily mean temperature above 10 °C from 1 Apr. through 31 Oct.

Vegetative growth and cane morphology and anatomy Vegetative growth and cane morphology During the 2015 season, vine vigor was assessed by measuring the following vegetative growth characteristics in L and N shoots/canes including: total L and N shoots per vine that emerged above the graft union, main and lateral shoot length between node 2 and 12, and internode length (shoot length/node number) and weight. Pruning weight per vine was also determined by adding the weights of all canes collected for freezing tests (see below) throughout the dormant season and those removed after final vine pruning in March 2016. During pruning, grapevines were trained back to the bilateral cordon system by retaining two 2-year-old trunks and one to three 1-year-old canes as spare parts for future trunk replacement.

Cane anatomy From 6 Aug. 2015 to 28 Mar. 2016 (six collections), internode 2 (cane tissue between node 2 and 3) and internode 3 (cane tissue between node 3 and 4) were sampled for anatomical analysis from the L and N canes. On each collection date, the internode tissue was excised by hand into cross sections (5-mm thick) using a razor blade and stored in a vial containing water (25 mL) at 4 °C. Cross-section samples were then transferred to a glass petri dish and submerged in 70% ethanol for light microscopy examination (Leica model S6D, Wetzlar, Germany) within 1 week from field collection. Images of internode cross sections were taken using a digitalcamera(LeicamodelMC170HD, Wetzlar, Germany) mounted on the microscope. Digital images were collected and analyzed using ImageJ software (National Institute of Health, Bethesda, MD, USA) to quantify anatomical structures including surface areas of pith, phloem, and xylem; vascular transport units (VTU; defined as the area bordered by adjacent xylem and phloem rays [see Figure 2]),andthenumberofxylemvessels and phloem fibers per VTU.

59 INTERNATIONAL JOURNAL OF FRUIT SCIENCE 5

A Large cane B Normal cane

1 cm 1 cm

Figure 2. Cross section of internode cane tissues with large and normal sizes in Cabernet franc grapevines collected on 23 Nov. 2015: (A) large cane (3× magnification), (B) normal cane (3× magnification), and (C) large cane (200× magnification). The solid lines delineate the boundaries of a vascular transport unit (VTU), which consists of a phloem VTU and xylem VTU. The letters “v” and “f” indicate xylem vessel and phloem fiber, respectively.

Freezing tolerance Canes were collected monthly from the vineyard between Aug. 2015 and Mar. 2016 corresponding to the same collection times for anatomical analysis. On each collection date, 15 canes of each size (L and N) were randomly sampled, placed in plastic bags to prevent moisture loss, and brought to the laboratory. Bud and cane tissues between node 4 and 12 were used for freezing tests. The FT of bud (primary, secondary, and tertiary) and cane (phloem and xylem) tissues was determined based on the oxidative tissue browning method (Zabadal et al., 2007). Briefly, L and N canes were kept in two separate groups then excised into two- node cuttings. Each group of cuttings was randomly pooled into three equal sub-groups (replications) and wrapped in moist cheesecloth, then covered in Aluminum foil. A thermocouple was attached to the surface of the cane internode to monitor cane temperature within each casing. The casings were placed overnight in a refrigerator at 4 °C. The foil casings were then placed into a programmable Environmental Chamber (Thermal Products Solutions, New Columbia, PA, USA). The environmental chamber was programmed to lower the temperature at a rate of 4 °C/h from –2°Ctoatargetlowest(killing) temperature that varied with time of collection. Each casing was removed from the chamber at targeted thermocouple readings and at 2 °C increments, kept at 4 °C overnight, then placed at room temperature for 48 h before the bud and cane tissue assessment was conducted. A cross-section cut into the bud exposed the bud tissues (primary, secondary, and tertiary) for visual injury assessment. Using a pair of pruners, a cross-section cut of the

60 6 T. M. TODARO AND I. E. DAMI

internode was made to expose the phloem and xylem for visual injury assessment. Bud, phloem, and xylem tissues that maintained green color after freezing were recorded as alive, while any brown tissue observed was recorded as injured. The percent damage of each tissue was computed by dividing the number of damaged samples by the total number of samples and multiplying by 100 at each target temperature. Using the damage percentage at each target temperature, and curve fitting method (Sigmaplot, San Jose, CA, USA), the temperature that corresponded to 50% injury was recorded as LT50. Furthermore, on each collection an additional set of 2-node cuttings (control) were kept at 4 °C and evaluated to account for field damage and adjust LT50 accordingly.

Soluble sugars Canes were collected monthly from the vineyard between Aug. 2015 and Mar. 2016, corresponding to the collection times for anatomical analysis and freezing test determination. A segment (3–5 cm long) of internode 2 (cane tissue between basal node 2 and 3) and internode 3 (between basal node 3 and 4) located at the proximal end of the cane at trunk base were sampledfromtheLandNcanesandstoredat–80 °C until further analysis. After bark tissue removal, the internode samples were ground in liquid nitrogen using a ‘Cryomill a11 basic’ (IKA Company, Wilmington, NC, USA). The samples were freeze-dried then extracted three times in 75% ethanol, with lactose included in the extraction buffer as an internal standard. Extracts were combined and samples were concentrated under nitrogen gas. Samples were re-dissolved in water and filtered through a 0.2-μM nylon filter. The concentrations of soluble sugars in cane internodes were quantified using a free zonal capillary electrophoresis (Zhao et al., 2016) and replicated four times.

Statistical analysis Statistical analyses of cane morphology and anatomy, FT (LT50), and soluble sugars were conducted using a paired T-test at p <0.05.Pearson analysis was used to determine the correlation coefficients between total sugars in the internode tissue and phloem LT50.

Results Weather Hourly minimum and maximum air temperatures from 1 Jan. 2015 to 30 Apr. 2016 are summarized in Figure 3A. The lowest temperature recorded was –22.8 °C

61 INTERNATIONAL JOURNAL OF FRUIT SCIENCE 7

on 20 Feb. 2015 and –18.7 °C on 8 Jan. 2016. The 2015 growing season had the following characteristics: last spring frost occurred on 6 Apr. 2015 and the first fall frost occurred on 17 Oct. 2015, resulting in 196 FFD and accumulating 1693 GDD.

Vegetative growth and cane morphology and anatomy Vegetative growth and cane morphology The mean number of shoots/canes per vine, which emerged at the base of trunks and above the graft union, was 10 (range of 6 to 22) and consisted of 60% L and 40% N canes (Figure 4A). Shoots grew nearly 4.3 m long (3–4.6 m) and possessed 40 nodes per shoot (35–45 nodes). Shoots and internodes in L were 20% longer than those in N (Figure 4B and C). Lateral shoots were present in both cane types, but more abundant (two-fold more total laterals, and six-fold more laterals >30cm)inLthaninNcanes(Figure 4D). Internodes were 188% heavier in L than in N canes (Figure 3E). At harvest, newly trained shoots produced a modest crop that averaged 10 clusters/vine and a yield of 0.23 kg/vine. The pruning weight per vine averaged 2.3 kg (or 1.28 kg per meter of cordon) with L canes weighing 123% heavier than N canes (Figure 4F).

Cane anatomy Samples for anatomical characterization were collected six times between Aug. 2015 and Mar. 2016. There was no change in parameters measured (Figure 2)in either cane type during that time period. Therefore, the results presented are means of measurements taken in all six collections. The surface areas of pith, xylem, and phloem of the L canes were two- to three-fold larger than those in N canes (Figure 5A). The surface area of xylem VTU was nearly four-fold larger in L than in N canes (Figure 5B). Similarly, the surface area of phloem VTU was two-

40 Maximum

Minimum 30

Air temperature (°C) -10

-20

-30 1 Jan 15 1 Apr 15 30 Jun 15 28 Sep 15 27 Dec 15 26 Mar 16

Figure 3. Hourly maximum and minimum air temperatures recorded at the OSU research vineyard from 1 Jan. 2015 to 30 Apr. 2016. The lowest recorded temperatures were –22.8 °C on 20 Feb. 2015 and –18.7 °C on 8 Jan. 2016.

62 8 T. M. TODARO AND I. E. DAMI

A B 120 C 12 a 10 a a 10 b 100 b 8 80 8 6 b 60 6 4 40 4 Shoots/vine

2 (cm) Shoot length 20 2 Internode length (cm) 0 0 0 Large Normal Large Normal Large Normal

D E F 2 6 30 a a Large a 5 Normal 25 1.6

4 20 b a 1.2 3 15 0.8 b b 2 10 Laterals/shoot

b Internode weight (g) 0.4 1 5 Pruning weight/vine (kg)

0 0 0 Total laterals Laterals >30 cm Large Normal Large Normal

Figure 4. Vegetative growth characteristics of shoots/canes with large and normal sizes in Cabernet franc grapevines: (A) number of shoots per vine, (B) shoot length between node positions 2 and 12 (measured on 6 Aug. 2015), (C) internode length between two consecutive nodes (6 Aug. 2015), (D) number of laterals per shoot between node positions 2 and 12 (6 Aug. 2015), (E) weight of two-node cutting (averaged over multiple collections between Oct. 2015 and Mar. 2016), and (F) pruning weight per vine. Means ± SE with different letters between L and N are significantly different by T-test at P < 0.05.

fold larger in L than in N canes (Figure 5B). Furthermore, the VTUs per cross section were more numerous (22% more) in L than in N canes (Figure 5C). The number of xylem vessels located within each VTU was 47% higher in L than in N canes. The number of phloem fibers located within each VTU was also 25% higher inLthaninNcanes(Figure 5D).

Freezing tolerance The FT of primary, secondary, tertiary, and phloem tissues followed the typical pattern of cold acclimation-deacclimationingrapevinesduringthedormant season. In October, LT50 of all four tissues ranged between –7.8 °C (primary bud in L) and –10.6 °C (phloem in N). In December, LT50 decreased more than two-fold since October and ranged between –18.3 °C (secondary bud in L) and – 21.9 °C (tertiary bud in N) and remained at its lowest level through February, when all tissue began to deacclimate. By the end of March, LT50 increased (FT decreased) and reached LT50 values of –7.8 °C (primary bud in L) to –14 °C (phloem in N; Figure 6). In October, LT50 of all tissues was not different between L and N canes. However, N canes had lower primary bud LT50 than L canes in November and December (Figure 6A). N canes also had lower secondary and tertiary bud LT50 than L canes in December (Figure 6B and C). In March, all four tissues had lower LT50 in N than in L (Figure 6). Phloem LT50 was lower in N than in L canes in December and March (Figure 6D). In this study, the FT of xylemwasnotdeterminedsincethelowesttargettemperatureusedwasnotcold

63 INTERNATIONAL JOURNAL OF FRUIT SCIENCE 9

a A 90 B 0.9 a 80 Large 0.8 Large 70 Normal 0.7 Normal ) 2 ) 60 2 0.6 50 0.5

40 b 0.4 0.3 30 a (mm VTU area b a

Surface area (mm a 20 0.2 b b b 10 0.1 0 0 Pith Xylem Phloem Xylem VTU Phloem VTU

110 C D 12 a a Large 100 10 Normal

90 8 b b a 80 6 b VTU Number 70 Number/VTU 4

60 2

50 0 Large Normal Xylem Vessels Phloem fibers

Figure 5. Cross-section anatomical characteristics of cane internodes with large and normal sizes in Cabernet franc grapevines: (A) surface area of pith, xylem, and phloem; (B) vascular transport unit (VTU) area of xylem and phloem; (C) vascular transport unit (VTU) number; and (D) number of xylem vessels and phloem fibers within each VTU. Means ± SE with different letters are significantly different by T-test at P<0.05. enough to kill 50% of the tissues. In fact, at the lowest target temperature of –24 °C, xylem injury was only 27% in L and 10% in N on 23 Feb. 2015. It is also noted that there was no damage in any control canes (not subjected to freezing test) from all collections except in February, when primary buds sustained similar injury in L and N canes of 3%. Furthermore, among the four tissues tested throughout the dormant season, xylem had the highest FT (lowest LT50) followed by, in order of decreasingFT,phloem,tertiary,secondary,andprimarybuds.

Soluble sugars In all collection dates, the following soluble sugars were identified in the internode tissue,fructose,galactinol,glucose,myo-inositol, raffinose, sucrose, and stachyose (Figure 7). Due to their predominant concentration and importance in grapevines, only fructose, glucose, raffinose, sucrose, and stachyose are presented. The total and individual soluble sugars followed the typical pattern of seasonal changes during the cold acclimation-deacclimation in grapevines. In fact, sugars were at their lowest concentration in August and then increased steadily during fall acclimation (October–December), reached maximum concentration in mid-winter (January–February), then decreased to the lowest level in March (Figure 7).

64 10 T.M.TODAROANDI.E.DAMI

A 0 B 0 Large Large Normal -5 -5 Normal * * -10 -10 * -15 -15 * *

Primary bud LT50 (°C) -20 -20 Secondary bud LT50 (°C)

-25 -25 8 Oct 15 23 Nov 15 21 Dec 15 25 Jan 16 22 Feb 16 28 Mar 16 8 Oct 15 21 Dec 15 25 Jan 16 22 Feb 16 28 Mar 16 C 0 D Large 0 Large -5 Normal -5 Normal

-10 * -10 * -15 -15 Phloem LT50 (°C)

Tertiary bud LT50 (°C) * -20 * * -20

-25 -25 8 Oct 15 21 Dec 15 25 Jan 16 22 Feb 16 28 Mar 16 8 Oct 15 21 Dec 15 25 Jan 16 22 Feb 16 28 Mar 16

Figure 6. Seasonal changes (8 Oct. 2015 to 28 Mar. 2016) of freezing tolerance (LT50, °C) of (A) primary, (B) secondary, (C) tertiary buds, and (D) phloem tissues in Cabernet franc grapevines. * indicates significant difference at P < 0.05.

The total sugar concentration doubled in January as compared to that in August (Figure 7A); and among individual sugars, raffinose and stachyose had the highest concentration increase of 17- and 11-fold, respectively (Figure 7E and F). When comparing individual sugar concentrations from October to January, fructose had the largest increase in concentration (53-fold) followed by glucose (30-fold; see Figure 7B and C)andsucrosehadthesmallestincrease(two-fold;Figure7D). When comparing total and individual sugars between canes of different sizes, we found that only in August, N canes had significantly higher concentrations of glucose and fructose than those in L canes. However, no differences of sugar concentrations were found on any other date (Figure 7B and C). Although the total soluble sugar concentration did not differ between cane size, a very significant negative correlation (R = –0.983, p < 0.001) was found between phloem LT50 and soluble sugar concentrations.

Discussion The extent of cold injury in grapevines varies with the severity of the freeze event (lowest temperature and duration of exposure) and the FT status of the genotype and its plant parts at the time of event occurrence (Zabadal et al., 2007). In this study, we confirmed the differences of FT between vine part organs with primary buds being the most cold sensitive and xylem the least to freeze stress and subsequent injury (Zabadal et al., 2007). Therefore, cold damage is often assessed first in dormant buds (typically primary and

65 INTERNATIONAL JOURNAL OF FRUIT SCIENCE 11

60 200 B A Large Glucose Total sugars 50 *** 150 Normal 40

100 30 20 50 10 Concn (mg/g DW) Concn (mg/g DW) 0 0

Date 60 80 D Sucrose C Fructose 70 50 60 40 50 30 40 30 20 20 10 * 10 Concn(mg/g DW) Concn (mg/g DW) 0 0

20 E Raffinose 8 F Stachyose 7 15 6 5 10 4 3 5 2

Concn (mg/g DW) 1 Concn (mg/g DW) 0 0

Figure 7. Seasonal changes (8 Oct. 2015 to 28 Mar. 2016) of sugar concentrations (mg/g DW) in large and normal canes in Cabernet franc grapevines: (A) total sugars, (B) glucose, (C) fructose, (D) sucrose, (E) raffinose, and (F) stachyose. Sugars were extracted from internode tissue between node 1 and 2. *, **, *** indicate significant difference at P < 0.05, 0.01, 0.001, respectively. secondary). Following winter injury, vine recovery management strategy involves an adjustment of pruning and training practices with the goal to re-establish vine structure and resume pre-damage production. If freeze injury is restricted to buds, the recovery of crop production can be achieved by increasing the number of buds retained after pruning in proportion to the level of bud injury (Zabadal et al. 2007). It has been demonstrated that pruning adjustment after cold injury led to a near normal crop in several grape cultivars (Dami et al., 2012; Keller and Mills, 2007; Wolfe, 2000). The 2014 and 2015 polar vortex freeze events (14 events of air temperature below –20 °C with an extreme of –31 °C) were severe and caused trunk damage in Cabernet franc. In this situation, vine recovery was accomplished by retraining new shoots for trunk replacement. The low yield (low sink) combined with high vegetative growth (high source) of recovering vines led to an imbalance between vegetative and reproductive growth including the emergence of highly vigorous “bull” shoots. In order to restore growth balance, grapevines are managed differently by training multiple shoots (called suckers) from the trunk base on a fan-like shape, thus the name, fan training system (Wolfe, 2000; Zabadal et al., 2007). Despite training multiple shoots (averaging 10 shoots per vine) and converting Cabernet

66 12 T.M.TODAROANDI.E.DAMI franc from VSP to fan training system, vines still produced 60% of L shoots. We measured several parameters to characterize vine vigor, including shoot length, internode length and diameter, and pruning weight. The L shoots were long, heavy with long internode and wide diameter, and possessed long and numerous laterals. The abundance of lateral shoot development in L canes is an indication of vigor and has been reported to be directly propor- tional to the vigor of the main shoot (Dry and Loveys, 1998). Therefore, it is concluded that the L shoots are considered excessively vigorous with similar vegetative and morphological characteristics reported previously (Byrne and Howell, 1978; Howell and Shaulis, 1980; Ru, 2011). Excessive cane vigor leads to increased cold damage (Byrne and Howell, 1978;HowellandShaulis,1980). The current study confirmed this obser- vation using controlled freezing tests and showed differences in LT50 as high as 5 °C between L and N canes. The repeated measurements of LT50 throughout the dormant season also showed that L canes were less cold hardy than N canes, particularly during acclimation (corresponding to tissue dehydration in fall) and deacclimation (tissue rehydration in late winter-early spring), but both had similar FT in mid-winter (January). It is possible that the compartmentalization of extra-(free) and intra-cellular (bound) water during these transition stages was not complete and/or altered in L canes (due to a more complex vascular system) leading to thepresenceofmorefreezablewaterthuscoldinjury(Levitt,1980; Sakai and Larcher, 1987). Even though water content in the internode was similar in both L and N canes (data not shown), it was not measured in specific tissues to account for water content and distribution between phloem, xylem, and bud tissues. It is also known that grape buds supercool to avoid intracellular freezing, whereas cane and trunk cells tolerate freezing temperatures by intracellular dehydration (Jones et al., 1999). Even though bud and cane tissue have different FT mechanisms, both tissues sustained extensive freeze damage in L canes. In order to advance our understanding of the reasons behind the sub- stantial difference of FT between L and N canes, we characterized the anatomical and biochemical (sugars) responses in respective cane type. The anatomical features of L canes were significantly and consistently different than those in N canes. The L canes possessed a significantly higher number of VTU, xylem vessels, and phloem fibers than those in N canes. The xylem VTU occupied cross-sectional areas four-fold larger in L than in N canes. Schubert et al. (1999) reported a positive relationship between increased xylem vessels and shoot length (vigor). Nevertheless, it seems counterintui- tive that vines produce large shoots with large anatomical structures, which may jeopardize their survival the following winter. One possible explanation for this phenomenon is that the anatomical structures of L canes in grapevine, which is a liana (climbing woody plant), were built as a mechanism to

67 INTERNATIONAL JOURNAL OF FRUIT SCIENCE 13

escape from biotic or abiotic stress (in this case freezing stress) near the ground and transport a large amount of water and nutrients (increased vessel number) long distance (long shoots) with a strong support system (increased VTU and fibers) by climbing over trees to ensure the production of seeds for procreation at a more distal location. These characteristics are adaptive strategies for efficient capacity of water conducting in angiosperms (Taiz and Zeiger, 2002; Tyree and Zimmermann, 2002). Other possible explana- tions of the phenomenon of increased freeze injury associated with plant anatomy are proposed as follows. First, the increased number of xylem and phloem VTU (tissues/cells) may also increase the sites of ice nucleation thus injury (Levitt, 1980; Sakai and Larcher, 1987). Second, L canes might have increased cavitation, which was reported to increase the susceptibility of xylem with large vessels to freezing injury (Tyree et al., 1994). Third, the large tissue/cell size may have contributed to their inability to contract, which is a critical process of cell dehydration during cold acclimation, which may have led to increased freeze injury in L canes (Levitt, 1980; Pearce and Ashworth, 1992; Singh and Miller, 1985). In this study, the seasonal changes of soluble sugars in Cabernet franc proceeded as expected and concur previous reports (Grant and Dami, 2015; Hamman et al., 1996; Jones et al., 1999). In fact, soluble sugar concentrations increased in the fall when Cabernet franc acclimated in response to low temperatures, reached the maximum level during the coldest months in mid-winter, and decreased in the spring during deacclimation. Soluble sugars have been implicated in the FT of herbaceous and woody plants including grapes; the correlation between sugar accumulation and increased FT is both qualitative and quantitative (Grant and Dami, 2015; Sakai and Larcher, 1987). Furthermore, a negative correlation between phloem LT50 and soluble sugar concentrations was also found and agrees with previous reports (Hamman et al., 1996, Grant and Dami, 2015; Grant et al., 2013). Possible roles reported for sugars in relation to FT included enhancing supercooling, preventing or slowing crystallization of ice, and increasing structural stability of cell membranes (Sakai and Larcher, 1987). In this study, due to the difference of FT between L and N canes, it was hypothesized that sugar levels would also be different between the two cane types; however, it was not the case. We attribute this finding to the lack of specificity of the tissue analyzed. In fact, soluble sugars were extracted from cane tissues (i.e., xylem, phloem, cambium, and pith combined), but not from buds. Even though the sugar concentration per dry weight of a cane segment was not different, it is possible that the partitioning of specific sugars is different between L and N; thus, the sugar concentration would be different if analyzed in a specific tissue (e.g., buds or phloem/cambium tissue only). We predict sugar levels in buds to be lower in L than in N canes. However, this hypothesis needs further investigation. The only significant difference of sugar concentration

68 14 T.M.TODAROANDI.E.DAMI

occurred in early August with N cane tissue having higher glucose and fructose than L cane tissue. There was a significant level of glucose and fructose in August then a sudden drop between August and October. In August, shoots were still green and did not mature (formed periderm) yet. Therefore, we attribute the sudden August “surge” of fructose and glucose to the photosynthetic nature of the internode tissues. In summary, this study confirmed the increased freezing injury of L (bull)canesascomparedtoNcanesinCabernetfrancgrapevineswhen exposed to similar subfreezing temperatures. It was also confirmed that vigorous shoots/canes, which correspond to the L canes in this study, have the following morphological characteristics: long and heavy canes with long and wide internode, and presence of numerous laterals. Among the three main parameters characterized in internode tissues, FT and anatomical structures, but not sugars, exhibited the most significant changes. We, therefore, conclude that the large and abundant anatomical structures of phloem and xylem contributed to the reduced FT of these tissues. The new knowledge gained about the influence of cane morphology on freezing tolerance of cane and bud tissues in Cabernet franc could be extrapolated to other cultivars, especially vigorous ones. However, the findings about the sugar level were not conclusive. This can be addressed in future studies by measuring sugar concentrations in specific tissues, such as buds. The findings of this study have also practical applications that are beneficial to grape growers. In order to mitigate the vicious cycle of excessive vigor— bull cane production—and subsequent cold injury, cane selection for trunk renewal and vine recovery after cold damage is critical. Leaving multiple shoots (>4) provides the opportunity to select canes of normal size for trunk replacement and to remove the undesirable vigorous and cold sensitive canes. In addition to the impact on trunk renewal, cane morphology would also influence the fruitfulness and winter survival of canes and spurs retained after pruning.

Acknowledgments

We thank Joshua Blakeslee and Ann Channon for carbohydrate analysis, and Tea Meulia at the Molecular and Cellular Imaging Center for advice and assistance in sample preparation for anatomical studies. We also thank Martin Goffinet, Emeritus at Cornell University, for his advice on anatomical measurements and quantification. We are grateful to Bruce Williams and Logan Walter for vineyard and field maintenance.

Funding

This research was funded by the Department of Horticulture and Crop Science, USDA/NIFA Specialty Crops Research Initiative Award Number 2010-51181-21599 USDA-NIFA, and Ohio Grape Industry Program.

69 INTERNATIONAL JOURNAL OF FRUIT SCIENCE 15

Literature cited

Byrne, M.E., and G.S. Howell. 1978. Initial response of Baco noir grapevines to pruning severity, sucker removal, and weed control. Amer. J. Enol. Viticult. 29:192–198. Dami, I.E., D. Kinney, and S. Li. 2014. Polar vortex and its impact on grapes. Ohio Grape- Wine Electronic Newsletter. 10 Jan., Issue: 2–6. Dami, I.E., and D. Lewis. 2014. 2014 Grape winter damage survey report HCS Series #816. Dept. Hort. Crop Sci., Ohio State Univ., OARDC, Wooster. 16 May 2014. wine grapes and protection strategies and methods. HortScience 43:1652–1662. Pool, R.M., and G.E. Howard. 1985. Managing vineyards to survive low temperatures with some potential varieties for hardiness. Proc. Intl. Symp. Cool Climate Viti. Enol., Corvallis, OR, 25–28 June 1985, pp. 184–197. Ru, S. 2011. Mechanistic view of shoot vigor in grapevines: Xylem anatomy, hydraulics and reproductive growth. Master’s thesis, Wash. State Univ., Pullman, Master’s thesis. Sakai, A., and W. Larcher. 1987. Frost survival of plants: Responses and adaptation to freezing stress (Ecol. Studies 62). Springer-Verlag, Berlin. Schubert, A., V. Novello, and E. Peterlunger. 1999. Shoot orientation affects vessel size hydraulic conductivity and shoot growth rate in Vitis vinifera L. Plant Cell Environ. 22:197–204. Singh, J., and W. Miller. 1985. Biophysical and ultrastructural studies of membrane altera- tions in plant cells during extracellular freezing: Molecular mechanism of membrane injury, p. 62–71. CRC Press Inc., Boca Raton, FL.

70 16 T.M.TODAROANDI.E.DAMI

Taiz, L., and E. Zeiger. 2002. Plant physiology, 3rd ed. Sinauer Associates Inc., Sunderland, MA. Tyree, M.T., K.J. Kolb, S.B. Rood, and S. Patino. 1994. Vulnerability to drought-induced cavitation of riparian cottonwoods in Alberta: A possible factor in the decline of an ecosystem? Tree Physiol. 14:455–466. Tyree, M.T., and M.H. Zimmermann. 2002. Xylem structure and the ascent of sap, 2nd ed., 283 p. Springer, Berlin. Wolfe, W. 2000. Vine and vineyard management following low temperature injury, p. 101–110. In J.M. Rantz (ed.). Proceedings of the ASEV 50th Anniversary Annual Meeting. American Society for Enology and Viticulture, Davis, CA. Zabadal, T.J., I.E. Dami, M.C. Goffinet, T.E. Martinson, and M.L. Chien. 2007. Winter injury to grapevines and methods of protection. Mich. State Univ. Ext. Bul. 2930. Zhao, L., A.M. Channon, N. Chattopadhyay, I.E. Dami, and J.J. Blakeslee. 2016. Quantification of carbohydrates in grape tissues using capillary zone electrophoresis. Front. Plant Sci. 7(818):1–14.