SW Michigan Fruit Update

Check the Index for earlier postings

August 15, 2005

Mark Longstroth
Bill Shane
Al Gaus

Weather

Last week’s weather was warm and dry with highs falling from the upper 80s to the mid 70s and lows in the 60s. There was no significant rain.  This week’s forecast is for cooler weather with a chance for rain near the weekend. 

Southwest Michigan Growing Degree Day Totals March 1 through August 14, 2005				Grapes April 1
Location	GDD 42	GDD 45	GDD 50	GDD 50
SWMREC:	3156	2775	2184	2162
Bainbridge:	3216	2831	2231	2208
Hartford:	2963	2588	2006	1986
Grand Junction:	3204	2822	2229	2205
Fennville:	2981	2610	2033	2013

Tree fruit

Trap catches were up a little last week, following low trap catches the first week of August. We are catching more apple maggot and blueberry maggot. Japanese Beetles are still common in some areas. Aphid and mite numbers are high in many crops. The second generation of Codling moth and the third generation of Oriental fruit moth are flying. Obliquebanded leafroller and Redbanded Leafroller trap catches are up.

Peach harvest continues with Allstar, Coral Star and PF 17. Oriental fruit moth trap catches are high and the third generation is flying. We set Biofix as July 27 at 2259 GDD base 45 at SWMREC and egg hatch will continue to about 3200 GDD base 45. Brown rot is showing up here and there. Two spotted spider mites are a problem in some peach blocks.

Plum growers should protect against apple maggot and brown rot.

In Apples, we caught more apple maggots last week than we have any other week. August is usually the month for this pest. See the Fruit CAT article on apple maggot monitoring and control. We biofixed on codling moth July 20, at 1581 GDD base 50, we are now at 2185 GDD. I expect the second generation to continue to about 2330 GDD base 50 and I also expect a third generation of Codling moth this year. Trap catch for Obliquebanded leafroller was up last week indicating the overwintering generation is out. I set biofix for this generation as Friday August 12 at 3100 GDD base 42s. Redbanded Leafroller flight is up.  See the article on summer leafroller control in the June 21, 2005 Fruit CAT Alert. Oriental fruit moth trap catches are up indicating the flight of the third generation. Grower will need to protect against this pest for several more weeks. Many growers have applied treatments for European red mite. If you have seven mites per leaf you should control European red mite. Late season pyrethriods, such as Danitol, can reduce mite numbers but also knock down predators and almost always result in heavy mite pressure late in the season and a large overwintering population of mites. The mines of the second generation of Spotted Tentiform Leafminer are showing up. Growers should be scouting for white apple leafhopper nymphs. Examine 50 leaves from 10 different trees and treat if the average is more than one nymph per leaf.

In Pears, European red mites and pear psylla numbers are building. Growers should be protecting pears from the second generation of codling moth.

Small fruit

Blueberry: Growers have harvested the third picking of Bluecrop and second picking of Jersey. Elliot harvest has begun in the south. In non-irrigated fields harvest has ended early due to poor fruit size and quality. Blueberry maggot and Japanese Beetles are out. Tussock moth larvae are a problem in some areas. Rufus Isaacs had an article on blueberry insecticides in the June 28 Fruit CAT Alert. Blueberry aphid numbers are low. Harvest fungicides should target Alternaria fruit rots. See the article in June 14 Fruit CAT Alert.

Grape veraison has begun in early varieties and early sites. Grape berry moth egg hatch increased sharply with the beginning of the third generation flight. Insecticide sprays to control egg hatch should be applied. See the article in the July 26 Fruit CAT alert on “Controlling mid-season grape berry moth.” Disease pressure this dry summer has been light and there is little need for fungicides mixed with the insecticides needed to control Grape berry moth. We have found powdery mildew symptoms on Concord fruit but not much downy mildew. Downy mildew is the disease we are worried about at this time. See Annemiek Schilder’s article on late season grape disease control in the July 26 Fruit CAT Alert.  The timing for controls of phomopsis and black rot has passed. Fruit rot symptoms of black rot have been found but the fruit is becoming more and more resistant as we approach veraison.

Strawberry growers should protect against leaf diseases and potato leafhopper.

Fall Raspberry harvest is underway. Blackberry harvest is underway and some growers are reporting white druplets from the heat.

Miscellaneous

Below are the Predicted Harvest dates for apples in Michigan.

Table 1. 2005 predicted peak harvest dates. Full bloom date Predicted harvest date Station McIntosh Jons Reds McIntosh Jons Reds Observer SWMREC 5-2 5-5 5-6 9-4 9-20 9-26 Shane Deerfield 5-8 5-9 5-10 9-8 9-27 10-4 Tritten Flint 5-8 5-9 5-10 9-9 9-28 10-5 Tritten Peach Ridge 5-7 5-8 5-9 9-8 9-25 10-2 Schwallier Ludington 5-8 5-10 5-11 9-10 9-30 10-8 Danilovich NWMHRS 5-20 5-22 5-23 9-14 10-6 10-13 Nugent Table 2. 2005 predicted peak harvest dates compared to normal and last year. Days ahead of normal Days behind of last year Station Macs Jons Reds Macs Jons Reds SWMREC 3 1 4 5 5 3 Deerfield 0 -3 -4 7 10 10 Flint 1 -3 -3 6 7 8 Peach Ridge 4 3 3 2 0 1 Ludington 6 5 0 2 -2 3 NWMHRS 6 3 2 6 -3 2   Table 3. Normal peak harvest dates for varieties for the Grand Rapids area. Variety Normal 2005 predicted Paulared 8-24 8-20 Gingergold 9-2 8-27 Gala 9-10 9-5 McIntosh 9-15 9-8 Honeycrisp 9-18 9-13 Empire 9-20 9-16 Jonathan 9-28 9-25 Jonagold 9-28 9-25 Golden Delicious 10-2 9-29 Red Delicious 10-5 10-2 Idared 10-10 10-6 Rome 10-15 10-12 Fuji 10-25 10-22 Braeburn 10-25 10-22 Goldrush 11-1 10-28