SW Michigan Fruit Update

Check the Index for earlier postings

Southwest Michigan, September 16, 2008

Mark Longstroth, Bill Shane

Apple maturity reports for 2008 are available by email or by going to www.maes.msu.edu/swmrec.  Look under publications for fruit newsletters. 
If you are interested in receiving the reports by email contact Bill Shane.  

2008 Weather

Cooler weather this past week.  Highs have been in the mid to upper 70s and lows near 50.  Last Friday, a storm system moved through the region and left about 8 to 11 inches of rain in most areas.  Soils are saturated and flooding is a problem in low-lying areas.  Harvest of fruit crops has been delayed and in some cases ended by the rain.  The forecast for the upcoming weeks is for continued cool.  The Growing Degrees below have been corrected for some missing data at sites marked with an asterisk*.

Southwest Michigan Growing Degree Day Totals March 1 through September 14, 2008				Grapes, April 1
Location	GDD 42	GDD 45	GDD 50	GDD 50
Berrien Springs:	3689	3215	2478	2468
Scottdale: *	3702	3228	2491	2483
SWMREC: *	3598	3120	2382	2388
Bainbridge:	3639	3078	2367	2360
Hartford:	3401	2944	2237	2233
Lawton:	3678	3206	2465	2460
Grand Junction:	3720	3250	2519	2513
South Haven:	3432	2978	2269	2262
Fennville: *	3380	2923	2214	2210

Tree fruit

Young trees should be irrigated to reduce drought stress.  Any supplemental irrigation should stop at the beginning of October.  San Jose scale crawlers are out and can cause fruit damage.  We are seeing this pest in more orchards this year.  Codling moth and Oriental fruit moth are flying.  Few Japanese beetles have been out recently. 

Peach harvest is complete.  Sprays to control peach leaf curl should be applied when leaf drop is underway.

Stone fruit such as Sweet Cherries, Tart Cherries and Plums, are beginning to go dormant with the combination of cool dry weather the leaves are changing color and falling.

Apple harvest is underway.  Growers are finishing Paulared and color picking Gala and McIntosh.  General harvest of Gala will begin next week.  Trap catch for codling moth is down but still high indicating the second-generation flight continues.  Codling moth entries are easy to see, especially on yellow skinned varieties.  It is doubtful that there will be a third generation this year.  Few Apple maggots have been caught for several weeks in SW Michigan.  Apple maggot emerges following rain, about ¼ of an inch is considered the trigger amount.  This means that growers can expect an increased emergence following rain.  Obliquebanded leafroller larvae are easier to find feeding on leaves.  With very little leafroller feeding on apple fruit.  Spotted tentiform leafminer mines can be found.  The new insecticides Delegate and Altacor seem to be doing a good job controlling this insect.  Green apple aphids are common in growing shoot tips.   White apple leafhopper leaf stippling and bronzing due to European red mites are generally scarce.  Growers should inspect calyx ends of apples for mite eggs.  San Jose scale crawlers are out and red spots on apple fruit is showing up.  Young trees should be irrigated and examined for potato leafhopper.

In Pears, Bartlett harvest is underway.  Both codling moth and oriental fruit moth can damage pear fruit at this time. 

Small fruit

Blueberry harvest continues.  Elliot is the variety being harvested now.  This weekend’s heavy rain will stop harvest and will end harvest for growers without a sure market.  Prices have been low.   Anthracnose ripe rot, small fruit and soft fruit have been a problem.  Leaf spots are a problem is some areas.  Drought stress is revealing other mineral nutrition problems such as iron and potash.  Japanese beetles and blueberry maggot flies are out. 

In Grapes, cool weather has delayed the Harvest of Niagara, which was scheduled to begin Monday.  This weekend’s heavy rain has postponed the start to next Monday, September 22.  Concord harvest will begin in about 10 days depending on when Niagara harvest has finished.  Grape berry moth trap catches are variable.  Vineyards that have historically had high grape berry moth pressure should be treated.  Fungicides at this time should target downy mildew.  Phomopsis berry rots are showing up.  With frequent heavy dews we expect downy mildew to increase.  Botrytis fruit rot has been found in wine grapes.

Strawberries should be protected against potato leafhoppers to prevent stunted growth.  Irrigation is very important do get good growth during this dry season.

Fall Raspberry harvest is underway.  The heavy rain over the weekend will ruin ripe fruit and end harvest for many growers.  Growers should protect against botrytis or gray mold in ripening fall fruit.