SW Michigan Fruit Update
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Southwest Michigan, September 14, 2009

Mark Longstroth, Bill Shane, Diane Brown-Rytlewski

Weather

The weather has been warm for September with highs near 80 and lows near 60.  No significant rain occurred but significant dews occur every morning with long periods of leaf wetness.  Soils are beginning to dry out.  Pleasant clear weather is forecast to continue through the week with a chance of rain early next week.  We continue to lag behind normal.  This is much more noticeable in grapes and field crops.  We are now about a week behind last year. 

Southwest Michigan Growing Degree Day Totals March 1 through September 14, 2009				Grapes, April 1
Location	GDD 42	GDD 45	GDD 50	GDD 50
SWMREC:	3506	3022	2271	2223
Fennville:	3262	2790	2050	2024

You can find weather and IPM information for Southwest Michigan at the Enviroweather website. 

Insects

Japanese beetle numbers are low.  Asian multicolored ladybird beetles are at high levels in some soybean fields where soybean aphids are also present in high numbers.  Growers should monitor their unharvested fruit planting for this harvest contaminate.  Codling moth trap catches are low.  Oriental fruit moth trap catches are down as cool night temperatures suppress moth flight. 

Tree fruit

In Peaches, harvest is winding down.  PF35 is being harvest and PF 27A should start soon.  Flavor is good.  Heavy morning dews mean that brown rot continues to be a problem in some orchards and fungicide treatments for brown rot are needed as fruit color.  Tarnished plant bug and stinkbugs are common in orchards with broadleaf weeds. 

In Plums,harvest is winding down.

In Apples, harvest of McIntosh and Gala is winding down.  Empires and Jonathans are also being harvested.  Some varieties of Golden Delicious are maturing rapidly and growers should check to see if their planting should be harvested.  The SW Michigan apple maturity report is posted at the SW Michigan Research and Extension Center web site fruit newsletters.  Sunscald-like symptoms are appearing on Gala.  Sooty blotch and flyspeck are present in some orchards, but not at high levels. Codling moth trap catches have declined for most orchards and Oriental fruit moth trap catches are significant in some orchards.  Oriental fruit moth is generally the insect of most concern during the month of September in southwest Michigan. 

In Pears,Harrow Sweet harvest is beginning with the winter pears Anjou and Bosc also being picked depending on the market. 

Small fruit

Blueberry harvest is essentially over.  Some growers are still harvesting Elliott.  The most recent Michigan Blueberry IPM Newsletter is posted at the Berry Entomology Lab. There is a Blueberry Virus Update Meeting scheduled for next Thursday, September 24 from 9 am to noon at Trevor Nichols Research Complex. 

In Grapes, harvest of table grapes continues.  Grapes have been the fruit crop most affected by the cool 2009-growing season.  Niagara harvest is projected to begin soon when sugar levels are high enough. Powdery mildew has been detected in some vineyards, but not many. The diseases of greatest concern now are botrytis and downy mildew.  Wet conditions spread botrytis, so susceptible varieties should be protected.  Heavy dews are common with extended wet periods in the morning.  This weather is favorable for the spread of downy mildew, so fungicides against downy mildew are required.  Numbers for the third generation of grape berry moth are low. Stings and tunnels can be found on the fruit.  Asian multicolored ladybug populations are high is some soybean fields in Berrien and Van Buren counties.  Growers should scout fields adjacent to grape vineyards.  These beetles will move into fruit plantings seeking sugars as the nights get colder and only a few beetles can contaminate grape juice.  See the most recent copy of Grape IPM Newsletter at the MSU Grape current conditions webpage. 

Fall raspberry and blackberry picking continues.  Growers should scout for Asian multicolored ladybugs in bramble plantings and adjacent soybean fields.  A significant disease of brambles in the fall is Botrytis fruit rot (gray mold).  Although the frequent morning dew and ground fog we’ve experienced are favorable for this disease, the temperatures have been cool.  The pathogen prefers temperatures closer to 70. Most fruit production is likely to wrap up by the end of the month.  Diseases such as anthracnose, cane blight, rust and botrytis overwinter on infected canes.  Pruning out all old fruited canes and infected primocanes after harvest, removing it from the field and destroying it is an important part of disease management.

Cranberries:  A MSU Cranberry school is being planned for October 22^nd in South Haven.