SW Michigan Fruit Update

Check the Index for earlier postings

June 21, 2005

Mark Longstroth
Bill Shane
Al Gaus

Weather

Last week was cooler with highs around 70. Lows temperatures were in the 50s. No rain fell after Monday’s rain. Areas close to the lake are very dry. Soil temperatures are about 75. This week’s forecast is for warmer weather with highs in the 80s.

Southwest Michigan Growing Degree Day Totals March 1 through June 19, 2005				Grapes April 1
Location	GDD 42	GDD 45	GDD 50	GDD 50
SWMREC:	1340	1128	816	795
Bainbridge:	1392	1174	854	832
Hartford:	1270	1063	759	739
Grand Junction:	1415	1200	880	855
Fennville:	1239	1037	739	719

Tree fruit

Codling moth and Obliquebanded leafroller trap catches continue. Rose Chafer is still about. 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. The second generation of Redbanded Leafroller is beginning to fly.

Apricot fruits are about 1.5 inches in diameter and earlier varieties are beginning to ripen.

Peach fruit are 1.25 inches in diameter. June drop continues and pit hardening has begun. Early varieties are hard but later varieties are still soft. Rose chafers are out and still pose a threat to the fruit. The second flight of Oriental fruit moth should be starting and trap catches are up in Berrien County. We are catching Peach Tree Borer adults and growers should be thinking about trunk sprays.

Cherries: Sweet cherry harvest has begun. Tart cherry growers are applying Ethrel and harvest should begin the middle of next week. Cherry fruit flies are being trapped in abandoned cherry plantings. No symptoms of cherry leaf spot have been found.

Plums are 22 mm in diameter.

Apple fruit are 1.25 inches in diameter. Fruit are still dropping. Fruit set is heavy in the tops of some trees and growers are complaining that they over thinned or that they need to hand thin. Fire blight is not common but some orchards are severely affected. Green apple aphids are becoming common and can spread the infection to healthy trees. The treatment threshold for Green apple aphid is when 3 to 4 leaves per terminal are infested. Codling moth trap catches are still high. We biofixed for codling moth on May 20 at 334 GDD base 50. We are now at 816 GDDs, 480 GDD past biofix. Activity for the first generation of Codling moth should end at about 1000 GDD after biofix, so we are only about half-way though the first generation. Obliquebanded leafroller Biofix was June 6 at 935 GDD. Egg hatch begins at 400-450 GDD past biofix about 1350 GDD base 42, so egg hatch is beginning. See the article in the June 7, 2005 Fruit CAT Alert. The second generation of Oriental fruit moth is emerging in Southern Berrien County. European red mites are hard to find. Spotted Tentiform Leafminer mines are easier to find.

Pear fruit are 1.25 inches in diameter.

Small fruit

Blueberry fruit are coloring. Harvest of early varieties will start late next week in the southern Berrien County. Cherry fruitworm flight is winding down but Cranberry fruitworm trap catches are increasing. Fruit worm egg hatch and feeding continues. Tussock moth larvae are out and causing severe damage in some fields. Blueberry aphids are becoming more numerous. Cane collapse due to phomopsis is common in some Allegan County blueberry plantings but not common in Van Buren County. Preharvest fungicides should target both Anthracnose and Alternaria fruit rots. See the article in last week’s Fruit CAT Alert.

Grape berries are buckshot sized. Vinifera bloom is ending. Rose chafer numbers are down. Grape berry moth egg hatch and feeding have begun. 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. Heat will end the harvest soon. Anthracnose fruit rots have been reported.

Early Summer Raspberries varieties are being harvested. Many varieties look poor due to winter injury.

Cranberries are blooming. A second fungicide application to control fruit rots is targeted for the end of bloom on rapidly growing pinhead fruit.

Miscellaneous

The next Monday Update meeting will be, Monday June 27 at the Overhiser Fruit Stand in Allegan County at 5 PM. There will be one MDA restricted use pesticide recertification credit available at this meeting.