SW Michigan Fruit Update

Check the Index for earlier postings

1 – Southwest Michigan, July 15, 2008

Mark Longstroth, Bill Shane

Weather

Temperatures have been generally mild over the past week with highs in the seventies to mid eighties and rainfall ranging from 1.5 to 2 inches.  Rainfall totals for the Fennville station since January 1 is 23 inches compared to 15 inches for the SW Station in the Benton Harbor region. 

Southwest Michigan Growing Degree Day Totals March 1 through July 13, 2008				Grapes, from April 1
Location	GDD 42	GDD 45	GDD 50	GDD 50
Berrien Springs:	1987	1702	1274	1274
Scottdale:	2074	1593	1183	1175
SWMREC:	1901	1623	1208	1202
Bainbridge:	1873	1600	1195	1188
Hartford:	1775	1507	1108	1104
Lawton:	1950	1667	1221	1216
Grand Junction:	1974	1693	1272	1265
South Haven:	1766	1501	1103	1100
Fennville:	1728	1461	1060	1056

Tree fruit

Leaf sampling for nutrient analysis is generally done from the end of July to early August.  San Jose scale crawler damage to fruit has been showing up more frequently in recent days.  Mite numbers are increasing but not a problem in most sites.  Japanese beetles are still active and will be around for another 3 to 4 weeks.  Green apple aphid numbers are still building.  Immature stinkbugs are becoming easier to find.  

In Apricot, the harvest of midseason varieties is underway. 

Peach fruit are about 1 ¾ to 2 ¼ inches in diameter.  We have seen several young peach plantings in the more northern region of the district with red hued leaves of nitrogen deficiency brought on by excess rain.  Harvest of PF-1 and Queencrest began approximately July 9^th, PF5B started July 15 and Early Star expected to start by July 19^th.  The estimated start of significant commercial Red Haven peach harvest for Berrien County is August 6, according to a degree-day model by Bill Shane.  Leaf loss due to bacterial spot continues on very susceptible varieties such as Babygold 5 and Suncrest peaches and Flavortop nectarines.  Stink bug puncture wounds to fruit will become more obvious as the current cohort of these bugs mature.  Watch for western flower thrip damage to peach and nectarine fruit when hot weather returns.    Oriental fruit moth adult catches continue to be high for the 2^nd generation—growers should consider the need for control measures against larvae of this generation.  Trunk spraying for peach tree borers is nearly done.

Sweet Cherry harvest is nearly done in Berrien County.  Quality and prices were generally good with only moderate cracking.  Alternaria fruit rot was only a minor problem.  Post harvest pruning can be done now.  General recommendations (see Fruit Cat Alert for July 26, 2005) are to:  prune no later than early September; avoid exceptionally heavy pruning; do not prune trees that have not filled their space.   For triangular shaped trees, the height of the bearing area of the tree should be no more than 3X the clear alleyway width.  For rectangular shaped trees, the height of the bearing surface should be twice the drive alleyway distance.

Tart Cherry mechanical harvesting has progressed rapidly for Montmorency. Fruit quality was generally very good with only minor problems with deep sutures and wind-induced bruising.   Balaton fruit quality has been good although a wide range of fruit sizes for this variety are been seen this year.  Yellow leaves due to cherry leaf spot infections are becoming easier to see but this disease is relatively light in most orchards.

Plum varieties ripening soon are Early Golden and Methley with Shiro and Early Magic (Santa Rosa type) shortly thereafter.  Growers should scout for white apple and potato leafhoppers. 

Apples are 1.9 to 2.6 inches in diameter.  Fire blight infections are still moving down infected branches but generally no new infections are showing up.  Trap catch for codling moth continue to be low for most orchards.  Codling moth larvae can be found in the fruit.  Apple maggot have been caught in high numbers in the SE region of the state and have been present for several weeks in SW Michigan.  Obliquebanded leafroller larvae are becoming easier to find but still feeding mainly on leaves for now. The new insecticides Delegate and Altacor seem to be doing a good job controlling this insect.  Spotted tentiform leafminer trap catches continue to be high.  White apple leafhoppers are scarce. Leaf bronzing due to European red mites and apple rust mites is becoming easier to find.  San Jose scale adult trap catch is very low and red spots on apple fruit due to crawlers are showing up in a few orchards.  Green aphid populations are still active where spray coverage is weak and terminal leaf growth is still continuing.  Young trees should be examined for potato leafhopper. Dogwood borer moth began emerging in mid June, indicating the need for trunk sprays in orchards with burr knots attractive to the insect.  .

Pears are about 2 inches in diameter.  Pear psylla numbers are generally low.  Sooty blotch and fly speck are a concern, especially for orchards in areas to the north receiving more rains.

Small fruit

Blueberry harvest of Bluecrop has begun for a few sites this week marking the beginning of the main season varieties.  Fruitworm feeding damage can still be found.  Blueberry maggot flies are out.  Preharvest sprays primarily target the diseases alternaria and anthracnose, as well as Japanese beetle and blueberry maggot. 

Grapes are at berry touch. Crop potentials vary greatly from vineyard to vineyard, depending on frost damage received.  Due to light crops last year, crop load potential was high coming into 2008.  Vineyards with heavy crops may have difficulty in ripening the crop properly this year if the heat unit accumulation continues to lag.  Grape leafhoppers are scarce.  Wine grapes need to be protected from potato leafhoppers.  Wine grapes need to be protected from potato leafhoppers.  Grape berry moth trap catches are down indicating the end of the first generation.  Larval stings can be found on some berries.  Fungicides at this time should target all four major fruit diseases; powdery mildew, downy mildew, black rot and phomopsis.  Black rot susceptibility decreases as veraison begins.

Strawberry renovation is underway. 

Raspberry and Blackberry harvest is underway.  Some fruiting canes are producing poorly due to disease (usually anthracnose) or winter injury.  Growers should be prepared to protect against Japanese beetles. 

Cranberry bloom has ended.

Upcoming Meetings

The next Monday Fruit Update meeting will be on Monday July 21, at the Fruit Acres Farm in Berrien County. The last three meetings of the season are on a biweekly schedule.

The annual Viticulture Day at the Southwest Michigan Research and Extension Center will be July 30.  The cost is $20 before July 18 and $25 after July 18.  A registration form is available at the Van Buren County MSUE Website; http://web1.msue.msu.edu/vanburen/vitregform.pdf