SW Michigan Fruit Update

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September 7, 2004

Mark Longstroth
Bill Shane
Al Gaus;

Weather

The last two weeks have been warm and summer like weather. Cool weather with highs in the 70s marked the beginning of the weeks. In the middle and late portions of the week, high temperatures were in the 80s with lows near 70. Showers two weeks ago have left soil moisture at good levels. A cold front with heavy showers moved through the area yesterday. Most areas received less than one inch of rain. The forecast for this week is for cooler weather with highs in the mid 70s warming back into the 80s later in the week. Longer range forecasts for the middle of the month are for warm dry conditions.

Southwest Michigan Growing Degree Day Totals March 1, 2004 through September 5, 2004
Location	GDD 42	GDD 45	GDD 50
SWMREC:	3394	2935	2218
Bainbridge	3431	2987	2268
Lawton:	3482	3008	2309
Hartford	3241	2780	2072
Grand Junction:	3444	2982	2264
Trevor Nichols:	3031	2592	1916

Tree fruit

Warm weather has increased insect activity around the 26^th of August. Fruit fly numbers are low only cherry fruit flies are still common. Codling moth trap catch and Oriental fruit moth trap catch numbers increased last week and now seem to be falling off. Damage reported from these two pests also increased. We expect to see more damage in the upcoming weeks. Trap catch of obliquebanded leafroller trap catch remains low.

Peach harvest is winding down. Oriental Fruit Moth egg hatch is well underway. Oriental Fruit Moth Biofix was April 29 at 300 GDD 45. We are at 2635 GDD-45 since Biofix and egg hatch is expected to end at about 3177 GDD after Biofix. Our trap catch numbers went up last week, increasing with the return of warm weather. Since we are at the end of peach harvest these late Oriental Fruit Moth are more of a problem for apple growers.

In Cherries, another wave of cherry leaf spot defoliation is taking the last of the leaves.

Plum harvest is winding down.

Apple growers are picking Gala, Honeycrisp and Macintosh. Some Honeycrisp in sandy sites is over mature. Codling moth trap counts spiked sharply last Monday indicating a heavy flight late last week. We are in the middle of the second-generation flight and egg hatch. Biofix on May 7 at 235 GDD base 50, we are at 1936 GDD after Biofix. The end of egg hatch is expected at 2100 GDD after biofix. About 250 GDD base 50 are needed from first trap catch to egg hatch, A heavy flight began about August 20 and we have accumulated 310 GDD (190 GDD since the 27^th) since then so a lot of eggs are beginning to hatch in apple orchards. Growers should be protecting later harvesting varieties. Be aware of expected harvest dates and PHI when you plan your control treatments. Late season Oriental fruit moth migrates out of the orchards were they are established to nearby plantings. Sprays to control Codling moth should also control Oriental Fruit Moth. Spotted tentiform leafminer and White apple leafhopper are out. Some apple orchards are severely bronzed from European red mite.

In Pears, harvest of Bartletts is finished and harvest of later varieties such as Bosc has begun.

Small fruit

In Blueberries, growers are finishing Elliott, the last variety of the season, and most growers are finished for the season. Growers are applying lime sulfur to control blueberry bud mite.

In Grapes, color is well developed in most vineyards. Harvest of early wine grapes and table grapes has aready begun. Harvest of Niagara should begin this week. Grape berry moth flight has increased for the last two weeks. Damage is heavy in some vineyards. Growers should be scouting hot spots and the edges of their vineyards for stings and other signs of recent berry moth activity. Grape leafhopper nymphs are spotty, most sites have very few. Phomopsis symptoms are easy to find in most grape vineyards. There is no effective treatment at this late date. Downy mildew has increased with the heavy dews common in late summer.

Southwest Michigan Grape Growing Degree Days form April 1, through Sunday September 5, 2004.
Location	Grape GDD
SWMREC:	2171
Bainbridge	2219
Lawton:	2217
Hartford	2025
Grand Junction:	2210
Trevor Nichols:	1884

In Strawberries, new growth looks good except where potato leafhoppers have been feeding. Strawberries are setting buds for next years crop and weed killers should not be used at this time.

Fall Raspberry harvest is in full swing. Fruit rots especially gray mold and blue mold are a problem for some growers. Captan is only fair against these diseases. Picnic beetles and ants are attacking over ripe fruit.