Southeast Michigan fruit regional report – July 16, 2013

First blueberry maggot trap catch for the season and blueberry harvest just getting started at some farms while summer raspberry harvest continues.


More rain for some fruit growers and none for others is the continuing story across the region. I know of a few fruit farms that have only seen a few tenths of an inch of rain over the past three to four weeks. Soil moisture supplies are adequate at most fruit farms. Our season is running behind normal again in terms of growing degree day (GDD) totals, but is almost normal when I look at growth stages and the start of harvest of our fruit crops.

East Michigan growing degree day totals for March 1 to July 15





Commerce (Oakland)




Emmett (St Clair)




Flint (Genesee)




Lapeer (Lapeer)




Petersburg (Monroe)




Pigeon (Huron)




Romeo (Macomb)




Tree fruits

Apples continue to size well where soil moisture supplies have been adequate; in the Flint, Mich., area they are mostly 2.125 inches. Lodi harvest is expected to begin late this week. Several summer apple varieties have begun to color in the past week. Yesterday (July 15) I noted some off-color Honeycrisp fruit that may be developing signs of sunscald, usually on trees that do not have an abundance of leaves this season. I need to see more fruit over the next week or so to tell for sure. Hand-thinning continues in apples.

I continue to catch a few apple maggots, all on yellow sticky cards. I am just now starting to catch oriental fruit moth adults in traps; this is the start of the second generation flight. Codling moth trap catch continues at a few farms, most have now finished first generation flight. Obliquebanded leafroller larvae have been found in a few apple blocks. Apple rust mite bronzing is being seen at more farms. European red mite eggs continue to be seen in low numbers. With this heat, I would expect to see populations to begin to build. Wooly apple aphid populations continue to move from the tree trunks to the terminal branches. There continues to be high numbers of predators being seen this season.

Pears are 1.5 inches at most farms where growers have a crop. All stages of pear psylla continue to be present. Growers need to remove suckers to help bring the population into check.

Peaches have taken on a swell in size this past week, with Red Haven approaching 2.5 inches in size and beginning to color. Harvest of some of the earliest varieties is expected to begin in the next few days. Fruit, twigs, branches and trunks continue to ooze from bacterial spot infection. X-disease continues to be seen.

Sweet cherry harvest is complete at most farms. Some had problems with fruit cracking on later varieties. Cherry fruit fly trap catches have been high in the past week; a post-harvest insecticide application may be required to reduce populations for next year. No spotted wing Drosophila have been trapped in any fruit crop in east Michigan this season. Cherry leaf spot disease symptoms are being seen in many blocks with yellowing leaves developing in the last week.

Tart cherry harvest is quickly wrapping up at most farms. Tart cherry fruit size continues to be a problem this season. No spotted wing Drosophila have been trapped in any fruit crop in east Michigan this season. Cherry leaf spot disease symptoms are being seen in most tart cherry blocks with yellowing leaves dropping to the orchard floor.

Plums remain 1 inch in size for European types and some are just beginning to color. Japanese types have put on a nice swell in the last week and continue to color; most fruit are now 1.5 inches in size. A few Japanese types will be ready for harvest in a week or so.

Small fruits

Strawberry renovation is ongoing at most farms. However, where fields are wet, growers have delayed getting started with renovation. Potato leafhopper feeding and leaf curling is being seen in most new plantings. Newly planted berries are runnering well.

Raspberry harvest continues for summer red and black raspberries. Canes of fall-bearing types are about 40 inches tall. Some farms have an abundance of lateral canes or “bud berries” this season that are continuing to mature, and a few of these berries are ready to harvest. These early berries are not a part of the main crop. We see this phenomenon more some years than others. Michigan State University Extension advises growers to keep an eye out for early spotted wing Drosophila infestations on these early bud berries.

Japanese beetle populations continue to slowly build in raspberries. Leaf curling from potato leafhoppers is being seen in both new and established raspberry plantings. No spotted wing Drosophila have been trapped in any fruit crop in east Michigan this season.

Blueberry harvest began in the last few days on early maturing varieties. Most of the main season varieties are continuing to color. My first catch of blueberry maggots was late last week on yellow sticky traps. No spotted wing Drosophila have been caught in traps in east Michigan this season. Birds are continuing to feed in most blueberry plantings.

Grape cane growth continues at a rapid pace. Japanese beetle populations continue to build in grapes in a few plantings. Grape berry moths continue to be caught in traps in commercial plantings. Downy mildew is just starting to be seen on grape leaves.

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