Vineyard IPM Scouting Report for week of 3 September 2012 UW-Extension Door County and Peninsular Agricultural Research Station Sturgeon Bay, WI

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1 NO Vineyard IPM Scouting Report for week of 3 September 2012 UW-Extension Door County and Peninsular Agricultural Research Station Sturgeon Bay, WI Grape quality measurements from grapes in the Wisconsin Varietal Trial located at the Peninsular Agricultural Research Station, Sturgeon Bay, Wisconsin. Quality parameters evaluated on 4 September Variety Soluble Solids ph TA Brix g/l Brianna Foch Frontenac La Crosse La Crescent Leon Millot Marquette MN MN Noiret NY Petite Pearl Vignoles

2 2 Below are last weeks grape quality results for comparison Grape quality measurements from grapes in the Wisconsin Varietal Trial located at the Peninsular Agricultural Research Station, Sturgeon Bay, Wisconsin. Quality parameters evaluated on 27 August Variety Soluble Solids ph TA Brix g/l Brianna Foch Frontenac La Crosse La Crescent Leon Millot Marquette MN MN Noiret NY Petite Pearl Vignoles

3 3 Harvest Pests I number of grape growers with fruit still on the vine are starting to notice some problems with fruit feeding pests. Growers are reporting observing sap beetles, yellow jackets, ants, and birds. I have not had reports of multicolored Asian lady beetles (MALB) being a problem, but with soybeans starting to shed leaves, be on the look out for MALB. At PARS we have observed yellow jackets feeding on table grapes. The yellow jackets are feeding directly on the berries, often feeding around the pedicel (berry stem). Yellow jackets in early season are mainly protein feeders, capturing larva or other insects. As the season progresses, yellow jackets switch food preference often feeding on soft fruits. The last few days the number of yellow jackets has increased considerably in the vineyard. After the berries become damaged other insect pests follow. Sap beetles will feed on damaged berries and are attracted to grapes that have started to rot and degrade. Sap beetles do not damage intact berries. Ants have also been reported feeding on damaged clusters. Before applying any control strategies, first approximate when you will harvest your crop. This will give you a timeline and help you select a product that has a pre-harvest interval (PHI) that fits your timeline. In most years, yellow jackets are only a nuisance to those harvesting grapes. However, this year yellow jackets seem to be at such high levels that they will likely impact latter maturing grape varieties yield and quality. You need to weigh your options. Should you apply an insecticide that will knock-down the population and then harvest or let the crop hang and accumulate sugar and risk yield and potential loss of grape yield and quality. Answering these questions thoroughly means you need to access what is happening in the vineyard every day from now until harvest. Damaged berries from direct fruit feeders and then sap beetle feeding could result in rot becoming a problem going forward. Sap beetles are known to be vectors transmitting rot spores and bacteria. Knowing what complex of insect pests you have and your timeline for harvest should direct your IPM management plan. I would venture that most all the grapes in the state will be harvested by mid- September other than ice wine grapes. This leaves only about 10 to 14 days before harvest and so if you are considering chemical control options for controlling yellow jackets, sap beetles, or MALB, look for products that have a PHI of less than 10 days. But again, base your selection on your timeline. This is the time of year when you should be scouting your vineyard every day, because changes are occurring very quickly. Sap Beetles Chemical control options are pyrethroids (Mustang Max, Pyganic, Renounce) and neonicotinoids (Clutch 50 WDG, Venom, Provado). All these products are labeled for use in grapes and will give some control of sap beetles although not all products have sap beetles listed on their label.

4 4 Yellow Jackets, Bees, and Wasps Chemical options that will repel, or kill bees, wasps and yellow jackets in grapes are malathion, Assail, Baythroid XL, Mustang Max, Provado 1.6F, or Sevin XLR. These products are not specifically labeled to control these pests. MALB Belay 2.13SC, Clutch 50WG, and Venom 70SG, and Scorpion 35S are labeled to control MALB. Other products that are not specifically labeled for control of MALB but have been effective in trials controlling MALB are Baythroid, Renounce, and Mustang Max. SWD Although SWD has not yet been confirmed in grapes in Wisconsin it is only a matter of time and so you may want to consider these resources below from the northeast. Insecticides efficacy ratings Even with netting birds sometimes have a way of outsmarting our protective barrier

5 Development of wine grapes in the grape variety trials at the Peninsular Agricultural Research Station (PARS) Sturgeon Bay, WI and West Madison Agricultural Research Station (WMARS), Madison, WI 5 Brianna at PARS Harvested Brianna at WMARS Harvested Foch at PARS Foch at WMARS Harvested Frontenac at PARS Frontenac at WMARS Harvested

6 6 Development of wine grapes in the grape variety trials at the Peninsular Agricultural Research Station (PARS) Sturgeon Bay, WI and West Madison Agricultural Research Station (WMARS), Madison, WI La Crescent at PARS La Crescent at WMARS Harvested La Crosse at PARS La Crosse at WMARS Harvested Marquette at PARS Marquette at WMARS Harvested

7 7 Development of wine grapes in the grape variety trials at the Peninsular Agricultural Research Station (PARS) Sturgeon Bay, WI. NY 76 at PARS Petite Pearl at PARS Two year old vines Vignoles at PARS Noiret at PARS Birds harvested the grapes Leon Millot at PARS Wild grapes at PARS

8 8 Degree Day 1 (base 50) Accumulation from April 1 to September 3, 2012 at Peninsular Agricultural Research Station in Sturgeon Bay, WI Date Year Average 2 4/1 to 9/ Modified method. 2 Average from 2007 to Degree Day 1 (base 50) Accumulation from April 1 to August 26, 2012 at West Madison Date Year Average 2 4/1 to 8/ Modified method. 2 Average from 2007 to No data this week Reminders Pay attention to PHI of pesticides Fungicide PHI listed on page 54 of the 2012 Midwest Small Fruit and Grape Spray Guide Insecticide PHI listed on page 56 of the 2012 Midwest Small Fruit and Grape Spray Guide Always consult the label that came with the product you are using Birds and other small animals are a problem especially more than ever during a drought as the animals look to fruit for moisture Keep in mind and abide by worker protection standards Downy and Powdery mildew will likely be a problem even after harvest and so continue your IPM program Please scout your vineyards on a regularly scheduled basis in an effort to manage problem pests. This report contains information on scouting reports from specific locations and may not reflect pest problems in your vineyard. If you would like more information on IPM in grapes, please contact Dean Volenberg at (920) or dean.volenberg@ces.uwex.edu