Northwest Michigan fruit regional report – September 2, 2014

Apple harvest has begun and quality is looking good. Codling moth and apple maggot catches are up in some areas. Grapes are ripening and some grapes have moderate to high disease pressure.

Growers are now harvesting early season apple varieties and overall size and quality looks good. We have received a few apples for maturity testing here at the Northwest Michigan Horticulture Research Center (NWMHRC). This morning, Sept. 2, we tested starches in Gingergold from an orchard in Leelanau County. Although these apples are not quite ready to be harvested, they were tasty and will be ready soon. Weekly apple maturity tests and reports will begin later this week. 

Apple growers are spraying for apple maggots and codling moths at this time. Second generation codling moth adults have been active for the last few weeks and in some sites, young codling moth larvae could be present at this time. As mentioned in previous reports, recent apple maggot and codling moth numbers have been variable throughout the region; some sites in Benzie County reached upwards of 18 apple maggots per trap, while we have caught few apple maggots in traps at the station this season. A few sites in Leelanau County were reported to have over 50 codling moths per trap this week; at the NWMHRC, we found a total of one codling moth.

After two weeks of no obliquebanded leafroller moth captures in apples, obliquebanded leafrollers are active at low levels here at the station at four moths per trap. We have observed and had reports of high European red mite numbers and in some orchards, mites have been challenging to manage.

Spotted wing Drosophila (SWD) captures have increased in the last two weeks and could be a concern in raspberries, blackberries and blueberries. Last week, we caught 10-fold more SWD in the region compared with the previous week. We have not collected SWD trap data from all of our monitoring sites at this time. However, we counted a total of 390 SWD in six traps at the station today, which is a small jump from last week’s total of 290 SWD. We will provide a more detailed report on SWD captures to FruitNet subscribers later this week.

In wine grapes, recent rains have increased the risk of Botrytis and cluster rots in early ripening varieties. Powdery mildew infection levels are now high on susceptible varieties at some sites. Insect activity has been light, but as fruit brix levels come up, wasps, ants and Drosophila fruit flies may become issues.

Fruit depredation by birds and raccoons may be severe this year. With such a small crop load in most vinifera vineyards, it won’t take much of a loss to birds to greatly reduce the harvestable crop. Raccoons may take a greater share than usual this year since a lot of the crop is low in the canopy on sucker shoots.

Cultivars in veraison:

  • Vinifera: Zweigelt, Pinot Noir, Dornfelder, Siegerrebe, Madeleine Angevine
  • Hybrids: Frontenac, Noiret, St. Croix, LaCrescent, Brianna

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