Wine Grape: Cold Climate Viticulture

Great Lakes Fruit, Vegetable & Farm Market EXPO Michigan Greenhouse Growers Expo December 8-10, 2009 DeVos Place Convention Center, Grand Rapids, MI Wine Grape: Cold Climate Viticulture Tuesday morning 9:00 am Where: Gallery Overlook (upper level) Room F Recertification credits: 1 (1C, PRIV OR COMM CORE) CCA Credits: PM(0.5) CM(1.5) 9:00 a.m. Managing Potato Leafhopper in Wine Grapes Rufus Isaacs, Entomology Dept., MSU 9:30 a.m. New, Sustainable Grape Varieties - Results from Trials in Southwestern Ontario Hans Peter Pfeifer, Ontario Grapes Consulting, Ontario, Canada 10:00 a.m. Cold Hardy Wine Grapes from Minnesota Peter Hemstad, Univ. of Minnesota 10:45 a.m. Modification of Cluster Compactness and Susceptibility to Fruit Rot in Riesling Grapevines Tom Zabadal, SWMREC, MSU Extension Paolo Sabbatini, Horticulture Dept., MSU Jennifer Wells, SWMREC, MSU Extension 11:00 a.m. Canopy Management in Pinot Noir: Effect on Fruit Quality Paolo Sabbatini, Horticulture Dept., MSU Tom Zabadal, SWMREC, MSU Extension

2006 Fruit and Vegetable EXPO Managing potato leafhopper in wine grapes Potato leafhopper Broad host range: many crop and non-crop plants Highly mobile adult stage Adults and larvae feed on grape leaves Lays eggs inside leaves Prefers new growth Rufus Isaacs & Steve Van Timmeren Dept. of Entomology Michigan State University Paolo Sabbatini & Pat Murad Dept. of Horticulture, Michigan State University Can have multiple generations per season Causes stunted vine growth, yellowing, and leaf cupping Michigan Grape and WineIndustry Council National Grape Cooperative Viticulture Consortium-East PLH management Scouting for potato leafhopper Regular scouting in spring, especially after weather fronts from the south If PLH detected, response based on vine susceptibility Consider vine ability to recover and the effect on fruit quality If needed, use effective chemical controls After rain storms, populations can increase quickly Check under leaves and on new shoots 100 leaves per vineyard block PLH adults are light green, move sideways if disturbed potato leafhopper grape leafhopper Color bright green light yellow Movement sideways forward Prefers wine grape juice grape Overwinters in the south here Manage PLH based on cultivar susceptibility Susceptibility is related to sensitivity to PLH Most susceptible Pinot gris, Pinot noir, Chardonnay, Cayuga white Intermediate Reisling, Vignoles, Cab franc Not susceptible Niagara, Seyval blanc, Vidal blanc Potted vines exposed to natural PLH population and the degree of leaf yellowing was recorded. Potted vines bagged with 0, 5, 10, or 20 PLH for *** days. Symptoms measured after ** days. More susceptible cultivar (Pinot gris) has a stronger response to lower infestation levels than resistant cultivar (Vignoles). Action threshold varies with susceptibility Contact: isaacsr@msu.edu

2006 Fruit and Vegetable EXPO Vine recovery from PLH damage Grape vines have a renowned capacity to tolerate leaf area loss. Regrowth of leaves after PLH damage may Foliar broad-spectrum insecticides Imidan 70WP (organophosphate) Sevin 80S/XLR (carbamate) Danitol 2.4EC, Capture 2EC, Baythroid XL (pyrethroids) Does PLH damage have more effect in vines with high crop load? Foliar insecticides for control of PLH Applied using a backpack sprayer on July 8, 2009. Days After Treatment Treatment 1 5 9 Untreated 4.3 a 1.8 a 2.1 a Sevin XLR 0 b 0 b 0.2 a Baythroid XL 0.2 b 0 b 0 a Actara 25WDG 0.8 b 0.4 b 1.4 a Clutch 50WDG 0.5 b 0.8 b 0.6 a Pyganic 0.1 b 0.4 b 1.1 a Systemic Insecticides Applied as soil or foliar sprays After application, absorbed into the vine Move inside the vine Within treated foliage: locally systemic movement From the roots to the foliage: systemic movement Can move to new foliage (soil application) Most effective on insects sucking or eating foliage Lower potential for breakdown and wash-off Long residual activity Low risk to workers, natural enemies Soil applications harmful to nematodes, soil insects? Soil-applied systemic insecticides All neonicotinoid insecticide class Imidacloprid. Bayer. Admire Pro 4.6F Soil insecticide (systemic protectant) for control of scale, mealybug, and phylloxera. Apply at 7-14 oz/acre to moist soil and irrigate with 0.5-1.0 inch water (rain is OK) within 24 h, or chemigate. 30 day PHI. Dinotefuran. Valent. Venom 70 SG (soil). Application rates for mealybug, leafhoppers, and thrips are at 5-6 oz/acre. One application max. and 28 day PHI. Thiamethoxam. Syngenta. (Not registered) Platinum 2SC Soil formulation active on leafhoppers, beetles. Clothianidin. Arysta. (Not registered) Belay 16WSG Soil formulation. Contact: isaacsr@msu.edu

2006 Fruit and Vegetable EXPO Control of potato leafhopper, 2006 Chemigation of hybrid vines with insecticides June 6 application (8-10 inch shoots) Admire (16oz), Platinum (16 oz), Belay (20 oz) Also applied Venom to Concord vineyard Measured PLH per leaf every 3 days Also sampled for Japanese beetle and berry moth Analysis of leaves for insecticide concentration at 1, 7, 14, 30 days later Soil samples for nematodes, soil insects PLH PLH Nymphs Adults/30 / 30 leaves leaves Effect of soil-applied insecticides on PLH PLH Nymphs 45 Platinum 40 Admire 35 Belay Untreated 30 25 20 15 10 5 0 0 10 20 30 40 Days After Treatment PLH PLH Adults Nymphs/30 / 30 leaves leaves Adult PLH 8 Platinum 7 Admire Belay 6 Untreated 5 4 3 2 1 0 0 10 20 30 40 Days After Treatment Concentration of Admire (ppm of imidacloprid) in grape leaves Soil-applied Venom for insect control Average concentration (ppm) ± S.E. In a separate trial, Venom insecticide provided long-term vine protection against PLH Avg. Number PLH Nymphs Per Plot 3.5 3 2.5 2 1.5 1 0.5 0 0 10 20 30 40 50 Days After Treatment Untreated Venom PLH management with systemic insecticides Foliar contact insecticides are highly active on PLH but do not protect the active growing shoot Admire highly effective for PLH control when soil applied at first detection (need regular scouting). Venom also controlled PLH as a soil application Soil applications gave over 3 weeks residual activity. Some additional Japanese beetle control, and should provide rosechafer protection. No benefit found for GBM control. (Foliar-applied Venom is effective MALB control - 1 day PHI). 2007 projects will test banded spring application. Also plan to compare to foliar sprays of Sevin, Venom, Assail, etc. Contact: isaacsr@msu.edu

SUSTAINABLE GRAPE VARIETIES and SUSTAINABLE GRAPE GROWING PROTOCOL Our Experiences in Southwestern Ontario, Canada presented by H. P. Pfeifer, Viticulturist, Harrow, Ontario, Canada 519-738-9337 /www.ontariograpes.com About 12 years ago, a group of grape growers (known as the Viticultural Roundtable) in Windsor/Essex, the southernmost part of Ontario, Canada, started a project to develop a protocol to evaluate the sustainability of our grape management system. This sustainable protocol has been modelled after the Swiss Vitiswiss/Vinatura System. Evaluation is based on grower-submitted records of fertilization, pesticide use assessment with the use of the EIQ-rating system, and best management practices. Also all known anti-resistance management practices are part of the protocol. The goal of the system is to encourage continual improvement in achieving production excellence while maintaining environmental sustainability, and to include as many growers as possible, while not compromising program objectives. As we progress towards better production practices, we are looking at ways to use our results as marketing tools for our region. We produced a document by consensus, and reviewed it annually. Growers are invited to self-assess, and to submit their records for group analysis. At this point, we have several years of data and are moving to streamline the record-keeping system required for the protocols. In 2007, The East-Central Ontario Fruit and Vegetable Growers Association (ECOFVGA) launched Fruit Tracker software for apples and berries which was designed to assist their Grower-members with managing their day to day record keeping of all the management practices (i.e. Spray records). Our group is working with them to field test a grape module. Fruit Tracker for grapes is in development now and will include the protocols from the Viticultural Roundtable of Southwestern Ontario. Feedback received from growers in early 2009 on the system suggested that there needs to be further enhancements and updates made to the original software to improve functionality and compatibility. This project aims to make the improvements and upgrades, relaunch the Fruit Tracker Software to all Ontario growers. We were pleased that both the Fruit Tracker Software and our Sustainable Protocol were regional winners of the Ontario Premier s Award for Innovation Excellence. During the same time, we established a research trial with the goal to search for sustainable wine grape cultivars. The focus was to find cultivars that produce high quality grapes (wine), are easy to grow, with better winter survival rate than traditional varieties, and with increased tolerance to diseases. At present, there are 3 new selections registered for certification with the Canadian Food Inspection Agency. The list of sustainable cultivars also includes Regent, Hibernal, and 4 more Swiss cultivars.

MODIFICATION OF CLUSTER COMPACTNESS AND SUSCEPTIBILITY TO FRUIT ROT IN RIESLING GRAPEVINES Thomas J. Zabadal and Paolo Sabbatini MSU Department of Horticulture Michigan State University East Lansing, MI 48824 Jennifer Wells MSU Southwest Michigan Research and Extension Center Benton Harbor, MI 49022 Many factors contribute to the susceptibility of grapes to fruit rot (Fig. 1). Some of these factors including choice of variety, control of pests like grape berry moth or powdery mildew, exposure of fruit to sunlight, and the target level of fruit maturity can be influenced by the grower. Weather is not controllable and unfortunately the Michigan climate can include heavy rainfall during the harvest period for wine grapes (Fig. 2). Cluster compactness is a major cause of fruit rot in grapes. Although cultural practices have been developed to modify cluster compactness (Zabadal and Dittmer, 1998 1 ) they are seldom utilized commercially. Because fruit rot is a major stress affecting the Michigan grape industry, we are working to develop methods that might be used by growers to modify cluster compactness, and therefore, to reduce the risk of fruit rot. Cluster compactness may be altered by mechanical, chemical or cultural practice strategies. A major impediment to chemical modification of cluster compactness is the need to have some chemicals registered for such a use. These include plant growth regulators (PGRs) and organic compounds that are labeled for other purposes as pesticides. There are, however, some chemical compounds that are considered inert ingredients and they would not require an EPA label approval as long as no claims for their pesticidal properties are made. We have begun to investigate the activity of several inert ingredient chemicals as well as other compounds to determine their ability to modify cluster compactness (Table 1). Our results indicate that several compounds are capable of reducing cluster compactness. However, there are several questions to be resolved before any of these compounds can be used commercially. What concentration or rate of application will reduce cluster compactness while maintaining a satisfactory crop level on the vines? What is the best time of application for a specific compound? Our work to date has involved individual clusters. What will be the wholevine affect of various treatments? What carryover affect will there be on vine performance in terms of node fruitfulness or even cane survival through the winter? Because we have screened several compounds, we have yet to compare one compound with another in terms of the cost to apply a treatment on a per-acre basis. All these issues will be addressed with our continued work on this topic. 1 Zabadal, T.J., T. Dittmer. Vine Management Systems Affect Yield, Fruit Quality, Cluster Compactness, and Fruit Rot of Chardonnay Grape. HortScience, Vol. 33(5):806-809. 1998.

Weather Variety Insects (GBM) Disease (Powdery Mildew) Cluster Compactness Fruit Maturity Fruit Exposure Fig. 1. An illustration of several factors that contribute the susceptibility of grapes to fruit rot.

Monthly rainfall for period April 1 through October 31, 2008 and 2009 14 12 11 days 2008 2009 10 Rainfall in inches 8 6 18 days 4 2 0 April May June July August September October Month monthly rainfall Apr_Oct 08_09.xls

Table 1. A listing of several compounds that are being evaluated for their ability to reduce cluster compactness. Compound Ammonium sulfate Ammonium nitrate Clove oil Citric acid Acetic acid Sulfuric acid Sodium hydroxide Copper sulfate Compound category Fertilizer Fertilizer Natural herbicide Weak organic acid Weak organic acid Strong inorganic acid Strong inorganic base Phytotoxic inorganic compound fruit rot abstract 11_09.word