SW Michigan Fruit Update

Check the Index for earlier postings

Southwest Michigan Fruit Update, September 4, 2007

Mark Longstroth, Bill Shane, Greg Vlaming

Weather

The past week has been dry, a break from the wet weather from August 18 to the 25^th.  Highs were continued in the 80s with lows in the 60s.  The soil now has good moisture.  Fall is on the way and leaves are changing color and falling on some tree varieties.  The forecast is for a dry week with highs in the 80s and lows near 60.  Later this week there is a chance of thunderstorms by the weekend, with temperatures falling into the 70s. 

Southwest Michigan Growing Degree Days (GDD) Totals March 1 through September 2, 2007				Grapes April 1	August Rain
Location	GDD 42	GDD 45	GDD 50	GDD 50
Scottdale	3904	3439	2707	2600	12.5
SWMREC:	3777	3314	2590	2492	11.4
Bainbridge:	3685	3232	2514	2413	11.8
Hartford:	3543	3088	2376	2281	10
Lawton	3874	3411	2676	2573	8.4
Grand Junction	3863	3401	2669	2572	7.2
South Haven	Missing data				8.8
Fennville:	3519	3066	2359	2279	6.5

Tree fruit

Some tree decline seen in low areas flooded by recent heavy rains.  This may be due to collar rot caused by phytophthora.  Trees affected by phytophthora often show early and dramatic color change in fall.

Peach harvest is winding down.  Only a few late varieties such as Laurol, Autumn Star, Harcrest, and PF35-007 remain to be harvested in the area.  In Allegan County, they are picking Glowing Star.  San Jose scale crawler damage, from the 2^nd generation, evident as bright red spots, was detected last week on peach fruit.

In Apples, Codling moth trap catches are low.  Apple maggot is still being caught.  Apples are relatively loose on trees.  Some orchards have received their 2^nd application of NAA for stop drop control.  Mite and leafhopper levels are relatively low although old mite bronzing is fairly common.  Lenticel spotting and skin cracking of Honeycrisp is fairly common, especially on sandy sites.  Bitter pit is becoming easier to see on Jonagold.  Some sooty blotch and flyspeck is present in commercial blocks.  Blister spot is widespread on Mutsu (Crispin) this year.  Somewhat similar symptoms are being seen on Fuji, which also has been known to be susceptible to this bacterial pathogen.  It is too late to treat for this pathogen this year.  

Empire harvest for fresh market and apple slice is underway. Significant harvest of Honeycrisp will start this week although some spot picking has been underway over the past week.  Some Jonathan will be harvested for processing toward the end of this week. 

Pear harvest is over.

Small fruit

Blueberry harvest has ended.  Fruit bud formation is underway.  Bud mite sprays should be applied in late September. 

Grape harvest is underway in Niagara, table grapes and early wine varieties.  Growers are reporting grape berry moth larvae and yellow jackets feeding on grape clusters.  Due to short time to harvest, pyrethroid insecticides such as Venom and Baythroid are about the only option.  These are also effective Asian multicolored ladybugs feeding in the clusters at harvest. Check the MSU Grape website for scouting updates.

Strawberry growth is good. 

In raspberries, fall raspberry harvest is continues.  With heavy morning dews growers should protect against gray mold.