What's In Your Vineyard?

With the exception of a major infestation of Japanese beetle in area vineyards, the 2007 growing season has been fairly uneventful as far as pests go. The scarce rainfall most areas received through post bloom limited the number of primary infection periods for the major diseases which have resulted in limited amounts of secondary inoculum available. Grape Berry Moth populations have not exploded and appear to be in a lull between generations at this time.

However, before you start cleaning up sprayers for storage and get to work on the harvesting equipment I would suggest that you get out in your vineyards and do a bit of scouting to catch any problems in their early stages. I have developed a list of some of this year's positives as well as some of the concerns to help you determine whether you need to get out into your vineyard blocks to see what is going on.

POSITIVES

• Bloom date at Fredonia Lab was approximately 6 days ahead of average.
• Research by Terry Bates indicates Concord vineyards can ripen 2 tons more than their average this season.
• Scarce rainfall through the post bloom period limited primary infections of the four major diseases.
• Grape berry moth populations and damage appear to be limited up to this point in the growing season.
• Scarce rainfall through the post bloom period has limited the amount of weed growth under the rows this year.

CONCERNS

• High over-wintering inoculum for downy mildew and black rot.
• More vineyards were not pruned or were minimally pruned this year.
• Good fruiting potential led to possible over crop situations in many vineyards.
• Lack of rainfall in many areas led to moderate drought conditions through mid July.
• Few growers did crop estimation to determine tonnage.
• Fewer growers did any thinning.
• More and more vineyards blocks receiving less than commercial management this year.
• Even with limited primary infection periods berry infections of powdery mildew, downy mildew and black rot could be found in vineyards during post bloom scouting.
• Loss of leaf surface due to Japanese beetle feeding.
• Good year for soybean aphids indicates a good year for Multicolored Asian Ladybeetle.
• Higher than average growing degree day accumulation indicates additional generations of grape berry moth are possible this year (late season damage).

Now is an excellent time to get out in the vineyard to scout for Grape Berry Moth. Damage is pretty easy to see in the purple or red varieties as the feeding damage will have a purple stain surrounding it. You can find complete information on the Grape Berry Moth Risk Assessment (GBM RA) Protocol in New York's Food and Life Sciences Bulletin No. 138 Risk Assessment of Grape Berry Moth and Guidelines for Management of the Eastern Grape Leafhopper on the web at: http://nysipm.cornell.edu/publications/grapeman/files/risk.pdf.

One of the important components of the GBM RA protocol is the scouting in four separate sections of the vineyard, two in the interior and two on the vineyard edge. This is done to ensure that all areas of the vineyard are covered to avoid missing outbreaks that do not necessarily follow what is written in the books.

The time spent walking from area to area while scouting for grape berry moth gives you an excellent opportunity to stop and stick you head in the canopy to see what else in going on in the vineyard. Make sure you have your vineyard maps, or at least some paper and a pen or pencil to record what you find and where. A supply of plastic zip lock bags, some small containers and even a digital camera are also valuable tools for collecting diseases, insects, maladies or just curiosities you find in the vineyard that you want to identify later.

The important thing is to get into the vineyard and scout. It will allow you to head off outbreaks of a pest before they become a problem or let you rest easy knowing that you have done a good job in keeping your vineyard blocks clean this year. Keep in mind that weather conditions and pest populations can rapidly change from now until harvest so regular scouting is recommended.

Grape Berry Moth trap catches continue to be extremely low in vineyards across the Lake Erie grape belt. No male moths were recorded in traps from high risk vineyards in the areas around Perrysburg, Sheridan, Forestville, Westfield and Ripley. Damage in the vineyard has also been more difficult to find this year as compared to previous years.

I would not recommend putting away the sprayer quite yet as late season damage from Grape Berry Moth has been seen numerous times in the past when things have looked good in July. My suggestion is to keep getting out into the vineyards on a regular basis and looking, especially concentrating on the high risk areas of your vineyard blocks.

Japanese Beetle can still be found feeding in vineyards but at much lower populations than seen even last week. They seem to be on their way out and any further insecticide applications in Concord vineyards will not be necessary. I would suggest that you keep looking in the smooth leaved wine grape varieties (which the Japanese Beetle seem to prefer and can defoliate large portions of the vines quickly) and in young vineyards where leaf surface is at a premium (especially in blocks using grow tubes) just to ensure that damage levels don't get out of hand.

Managing Risk In The Implementation of New Production Practices In Vineyards
What do you consider the top 10 production practices you use to ensure profitability in your vineyard operation? Do you track the costs involved with each practice to assist you in making informed management decisions? These are two questions that are being addressed in a new project, funded by the Northeast Center for Risk Management Education, which hopes to build upon the success of the grower-to-grower interaction found in the Lake Erie Coffee Pot meetings and the increased availability of information through the 3-minute viticulture digital videos produced by Terry Bates.

This project aims to help Concord growers explore new production practices for their operation by combining the research-based information on a practice, in the vineyard knowledge provided by growers who have incorporated the practice into their operation and an economic worksheet to compare the cost of continuing a current production practice with the cost of implementing the new practice. Videos and worksheets will also be developed for growers looking to diversify by planting more profitable, yet sometimes riskier, wine grape varieties for sale to the small winery market.

Your input is needed to ensure that this project can capture the most important production practices for both ensuring the profitability of growers wanting to continue in Concord grape production as well as those who are looking to expand into wine grape production. Let us know what production practices 1) you feel are key to the success of your vineyard operation, 2) you would like to know more about from your fellow growers before trying them in your own vineyard and 3) what information on production practices do you feel would be helpful in making the decision on whether diversifying into wine grapes is right for you?

Grape berry moth - eggs were observed on Concord berries in border rows next to the woods at two severe risk sites examined. Border row cluster counts indicated that at one site, 6% of clusters had GBM eggs and 40% of clusters had at least one berry with GBM feeding injury. At the other severe risk site, 4% of clusters had GBM eggs and 24% of clusters showed GBM injury. However, GBM injury levels remained low at other high risk sites examined. Growers were also reporting low injury levels at high risk sites.

Since GBM levels have been very low up to this point at high risk sites then there are 2 options:

1. Delay spraying but carefully scout high risk sites at least once/week until harvest to determine if threshold injury levels have been reached. (Threshold levels - > 6% injured clusters now, > 15% injured clusters during fourth week in August). If thresholds are reached then immediately apply an insecticide application.
2. Apply an insecticide application now then continue to carefully scout high risk sites at least once/week until harvest to determine if an additional application is needed. Blocks with rows parallel to the woods can be sprayed 8 - 10 rows from the wooded edge while perpendicular rows need to be protected at least 3 post lengths from the edge.

Grape berry moth injury on Concord Berry

Grape berry moth injury on Niagara Berry

Powdery mildew - levels remain low on leaves and clusters at sites examined.

Powdery Mildew on Niagara leaf

Black rot - at this point in the season, berries are resistant to BR infections so for this season there is one less problem to worry about.
(See Tim Weigle's Crop Update).

Black Rot on Concord Berries

Refer to the 2007 New York and Pennsylvania Pest Management Guidelines for Grapes.

NYS IPM Fact Sheets for Grapes - http://www.nysipm.cornell.edu/factsheets/grapes/default.asp