SW Michigan Fruit Update

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June 13, 2005

Mark Longstroth
Bill Shane
Al Gaus

Weather

Last week was hot with highs in upper 80s. Lows temperatures were in the 60s. Scattered thunderstorms moved across the region most of the week. Precipitation from these storms varied from over an inch to less than a tenth of an inch. On June 8, Hail fell in some areas of Northern Berrien and Western Van Buren counties seriously damaging fruit in that area. The remnants of a hurricane brought rain to the area Sunday night and Monday morning. Rainfall amounts were less than an inch close to the lake but much more than an inch away from the lake. Areas close to the lake are very dry. Soil temperatures are about 75. This week’s forecast is for cooler weather with highs in the 70s.

Southwest Michigan Growing Degree Day Totals March 1 through June 12, 2005				Grapes April 1
Location	GDD 42	GDD 45	GDD 50	GDD 50
SWMREC:	1178	986	709	687
Bainbridge:	1224	1028	743	720
Lawton:
Hartford:	1117	931	662	642
Grand Junction:	1244	1049	764	739
Fennville:	1079	898	635	615

Tree fruit

Insect activity increased with warmer temperatures. Rose chafers came out in force and both Codling moth and Obliquebanded leafroller trap catches increased. Few fresh plum curculio egg-laying scars were found. Potato leafhoppers have been found. We are now catching greater and Lesser Peach Tree borers and growers should be thinking about trunk sprays for Borer control.

Apricot fruits are about 1.25 inches in diameter. Trees in sandy sites show drought stress and wilting.

Peach fruit are 1.25 inches in diameter. June drop continues and pit hardening has begun. Rose chafers are out and often attack young peach fruit.  Oriental fruit moth egg laying has ended. Flagging of peach shoot tips from Oriental fruit moth larvae were reported last week. Tarnished plant bug feeding scars have been found on young fruit. Bacterial spot symptoms continue to appear. We are catching Peach Tree Borer adults and growers should be thinking about trunk sprays.

Cherries: Sweet cherries are coloring and birds are eating the fruit. Tart cherry fruit are yellowing. Sunday’s rain was a cherry leaf spot infection period.

Plums are 20 mm in diameter.

Apple fruit are an inch in diameter. Fruit are differentiating into several size classes. Still dropping.  Fire blight appeared in more orchards last week. The storm Sunday was a trauma infection period for fire blight, especially were there was hail. Green apple aphids are out and can spread the infection to healthy trees. New apple scab symptoms were found from the May 22 infection. If scab lesions are found in the orchard, growers should continue to apply protectant materials to suppress fruit scab. The first generation of Oriental fruit moth is ending. Obliquebanded leafroller adults were caught in good numbers. Moth Catches were reported Friday June 3 (870 GDD 42) and Monday June 6 (935 GDD base 42). We are setting obliquebanded leafroller Biofix at June 6 at 935 GDD. We are now at 1178 Base 42. Egg hatch begins at 400-450 GDD past biofix. This would be about 1350 GDD base 42. See the article in the June 7, 2005 Fruit CAT Alert. Codling moth trap catches are high. We biofixed for codling moth on May 20 at 334 GDD base 50. We are now at 709 GDDs, almost 375 GDD past biofix. Activity for the first generation of Codling moth should end at about 1000 GDD after biofix.

Pear fruit are an inch in diameter.

Small fruit

Blueberry fruit are sizing well (10-12 mm). Cherry fruitworm and Cranberry fruitworm egg hatch and feeding continues. Tussock moth larvae are out and causing severe damage in some fields. Blueberry aphids are becoming more numerous. There are a series of upcoming blueberry meetings on June 15 and June 27.

Grape bloom is ending. Botrytis rot (brown shriveled flowers) showed up in some vineyards during bloom. Vinifera grapes are blooming. Rose chafers and rose chafer feeding damage are easy to find. Grape berry moth adults are being trapped, and egg laying has begun. Sunday’s rain was a black rot infection. Phomopsis, black rot and downy mildew symptoms can be found. Growers should be protecting the flower clusters from diseases with bloom sprays or post bloom sprays before our next rain.

Strawberry harvest is moving quickly. Fruit bronzing due to flower thrip feeding was reported. Verticillium wilt symptoms were also reported.

Early Summer Raspberries varieties are coloring.

Cranberry bloom has begun.

Miscellaneous

The next Monday Update meeting will be, Monday June 20 at Fruit Acres Farm near Coloma in Berrien County at 5 PM. There will be one MDA restricted use pesticide recertification credit available at this meeting.