2019 Fruit Pest Update

September 18, 2019

2019 – 2020 Midwest Fruit Pest Management Guide

Apple harvest has begun! Fruit are continuing to be about 6 – 8 days behind normal years due to the weather this season. Apple maturity reports will be published weekly on the Peninsular Agricultural Research Station website https://peninsular.ars.wisc.edu/apple-cherry-pest-update/.

As we approach harvest, make sure to double check the preharvest interval for any product you might use!

INSECT & DISEASE CONTROL

APPLE

Disease Pressure – A late season apple scab spray may be needed in blocks with active apple scab lesions due to the high amount of fog/mist we’ve had over the past week.

Insect Pressure – There is moderate apple maggot pressure in all scouted orchards and high pressure in blocks adjacent to abandoned orchards. Codling moth pressure is light as we are at the end of the second generation flight. There is still a bit more pressure farther north at this time. Adult plum cuculio beetles have been caught in two unsprayed orchards this past week. No brown marmorated stink bugs have been caught this year, but other types of stink bugs are active. There appears to be some stink bug or tarnished plant bug damage showing up on fruit in some blocks with heavy insect pressure. The feeding from both species looks very similar to bitterpit. If you are noticing higher amounts of what you think is bitterpit, it is worth checking the fruit closely to evaluate whether it is actually insect feeding damage.

When testing for apple maturity, it is important not to go by color alone this year, because color is developing faster than the apples are maturing. Make sure to use a variety of tests so that you ensure your apples are harvested at the optimal time.

CHERRY

The cherry season is basically complete. Any last hedging should be finished up this week so that the branches can heal over before the winter. Fall is also a good time to apply white latex paint to trunks to prevent southwest winter injury. Those wounds give borer insects an entry point which leads to early tree decline as larvae burrow under the bark.

GRAPE

Grape fruit maturity data are included in the most recent Fruit News and local data is posted on the PARS website. https://peninsular.ars.wisc.edu/apple-cherry-pest-update/

Wisconsin Fruit News:

Wisconsin Fruit News Volume 4, Issue 11

Fruit quality data Brix and TA from berries sampled from the West Madison Agricultural Research Station (WMARS) in Madison, WI, as of September 10^th.

Reports have come in that low to large levels of codling moth and moderate levels of apple maggot were caught in monitoring traps this week.

As harvest time approaches, we have noticed a sudden shriveling of berries and wilting of clusters. Read more in Berry Shriveling in grapes: Late Bunch Stem Necrosis.

Updates from the UW-Madison, Division of Extension Insect Diagnostic Lab.

MSU is still collecting grape powdery mildew samples.

Peninsular Agricultural Research Station Vineyard Scouting Report.

Grape Scouting Report: Not much to report but be on the lookout for multicolored Asian lady beetles and wasps.

Door County Fruit Crop Pest Report, September 9, 2019.

Grape Variety Fruit Maturity Evaluation – September 4, 2019