SW Michigan Fruit Update

Check the Index for earlier postings

June 20, 2006

Bill Shane, Mark Longstroth

Weather

Temperatures rose last week from the 70s into the 90s by the weekend.  Rain fell Sunday with rainfall totals ranged from a tenth to 0.75 inches.  Larger amounts fell away from Lake Michigan.  Topsoils near the lake are very dry.  Growers are irrigating.  Soil temps are in the 70s.  This week’s forecast is for warm weather with highs in the 80s and chance of thunderstorms.  The GDD below are from the Enviroweather site.

Southwest Michigan Growing Degree Day Totals March 1 through June 18, 2006				Grapes, from April 1
Location	GDD 42	GDD 45	GDD 50	GDD 50
Scottdale:	1358	1131	804	774
SWMREC:	1323	1087	750	718
Bainbridge:	1391	1151	811	777
Hartford:	1233	1011	699	672
Lawton	1407	1171	832	817
South Haven (April 1)	1064	883	615	615
Grand Junction:	1391	1156	826	789
Fennville:	1219	993	681	654

General Insect Activity

Potato leafhoppers are becoming more abundant.  Japanese beetles are emerging.  Red-banded leafrollers are flying again.  Tarnished plant bug activity is declining.  Rose Chafers are out but not in large numbers.  Plum curculio activity is light.  You can monitor the GDD model for some pests at the Enviroweather site.

Tree fruit

Apricot fruit are 2 inches in diameter. 

Peach fruit are 1.75 inches in diameter.  Growers are still hand thinning.  Large oriental fruit moth larvae are being found.  The second generation of OFM should be emerging this week. Growers and scouts should recharge their lures for this flight.  Peach fruit show tarnished plant bug damage and rusty spot (powdery mildew).  Bacterial spot is generally minor. 

Sweet cherry harvest has begun.  Birds have been a big problem this year and growers have lost a great deal of fruit.  Fungicides to control brown rot should be applied.  Cherry fruit fly traps should be out, especially where sweet and tart cherry varieties are grown together. 

Tart cherries are turning red and growers will be applying Ethrel this week.  Growers need to protect against cherry leaf spot.  Cherry leaf spot has been reported in orchards where DMI fungicides Indar were used, indicating that resistance was the issue and not poor application timing.  Cherry fruit fly are seldom a serious problem in SW Michigan in areas where only tarts are grown, the flies seem to emerge late at about harvest time and develop in fruit left on the trees. 

In Plums, the crop looks decent.  Shoot growth continues and growers need to protect against black knot.  White apple leafhoppers are causing stippling of the leaves. 

Apple fruit drop continues.  The fruit are about 1.25 inches in diameter.  We have had 248 hours of leaf wetness since petal fall so sooty blotch and flyspeck symptoms should show up in unsprayed orchards soon.  Growers need to maintain scab protection if they find leaf lesions in their orchards.  Growers should continue to protect against powdery mildew in problem orchards.  Fire blight symptoms and bacterial ooze are not common but some orchards are showing more symptoms.  Trauma blight could be a problem if we get severe weather in these orchards with oozing shoots.  Oriental fruit moth is between generations.  Codling moths trap counts are down but egg hatch continues.  Many growers are applying the second cover spray.  Obliquebanded leafroller are being caught in the area.  Biofix for Obliquebanded leafroller occurred last week on Monday June 12 at 1150 GDD base 42.  European red mites eggs are being found.  Apple maggot traps should be out.

Small fruit

Blueberry fruit are beginning to color in early varieties.  Weymouth harvest will start later this week in Berrien County.  Protection against anthracnose fruit rot should be the main disease concern now.  Cane collapse due to phomopsis is occurring.  Cherry fruitworm and cranberry fruitworm are being caught in pheromone traps this means egg laying is continuing. Blueberry Maggot will be emerging soon and traps should be out.

In Grapes, fruit clusters on primary shoots are at shatter and clusters on secondary shoots are blooming.  Rose Chafers are feeding in some vineyards.  Post bloom sprays are due.  Grape berry moth numbers are high.  Grape flea beetle larvae are feeding on the leaves in unsprayed vineyards.  Some growers are still deciding if they will harvest.  Phomopsis leaf lesions are common in most plantings.

Strawberry harvest will probably end at the end of the week.  Fruit has ripened rapidly due to the heat last week and fruit size is falling off.  Fruit quality has been good.  Irrigation is important to maintain good fruit size.  We expect renovation to begin early next week.

Raspberry harvest will begin soon.  Growers should be scouting for Japanese beetles. Pre harvest fungicide and insecticide sprays should go on soon.

Miscellaneous

The next Monday Fruit Update meeting will be Monday June 26, at the Fruit Acres Farm in Berrien County, at 5 PM.