SW Michigan Fruit Update
August 17, 2004
Weather
Temperatures have been cool. Highs in the 70s with lows about 50. This week’s weather forecast is warmer weather with a chance of showers or thundershowers.
Southwest Michigan Growing Degree Day Totals March 1, 2004 through August 15, 2004 |
|||
Location |
GDD 42 |
GDD 45 |
GDD 50 |
2851 |
2455 |
1844 |
|
Bainbridge |
2905 |
2503 |
1888 |
Lawton: |
|||
Hartford |
2732 |
2333 |
1728 |
Grand Junction: |
2932 |
2530 |
1910 |
2547 |
2167 |
1589 |
|
Tree fruit
Fruit continue to size well. Fruit flies are out in cherries, apples and blueberries. The wet weather we have had should bring out another flight of flies as it warms up. Japanese beetles numbers are low. Cool weather has kept insect activity low. Codling moth trap catch is steady. Oriental fruit moth trap catch numbers are up in the South. Trap catch of redbanded leafroller and obliquebanded leafroller is low. All of these pests should pick up back soon.
Peach harvest is starting to slow down. Size is excellent. The flight of the third generation of Oriental Fruit Moth is well underway and egg hatch has begun. Oriental Fruit Moth Biofix was April 29 at 300 GDD 45. We are at 2200 GDD-45 since Biofix and egg hatch begins at about 2250 GDD after Biofix.
In Cherries, some growers have applied another cherry leaf spot spray to keep their leaves on a little longer.
Plums are softening. Harvest of early European varieties has begun. Brown rot is showing up as the plums ripen. Growers should protect against apple maggot.
Apple growers are Mollies Delicious and finishing Paula Red. Some growers will start to color pick Gala and Macintosh soon. As it becomes wetter, growers include fungicides in their cover sprays to reduce sooty blotch and flyspeck. Fire blight is common in the region and severe in some orchards. We are seeing the early fall coloration and indicating the collapse of rootstock.
Codling moth
trap catches are low and steady. We are in the middle of the second-generation flight and
egg hatch. Biofix on May 7 at 235 GDD base 50, our current total is 1844 GDD, and we are
at 1609 GDD after Biofix. Egg hatch for second-generation codling moth is underway. The
end of egg hatch is expected at 2100 GDD after biofix. The end of egg hatch is several
weeks away, but it is doubtful we will see a third generation of Codling moth this year.
The third generation flight of Oriental
Fruit Moth and egg hatch is underway south of I 94. Spotted tentiform leafminer adults
are emerging. White apple leafhopper
larvae are out. Some apple orchards are bronzing from European red mite. For European red mite the treatment
threshold for this pest is 7.5 mites/leaf.
In Pears, second generation codling moth can attack pears. Pear psylla numbers are building in some orchards.
Small fruit
In Blueberries, Jersey and Rubel harvest is ending. Growers are picking Elliots. The season is over for Berrien growers. Both blueberry maggots and Japanese beetles are out. Tussock moth larvae are out. Alternaria is the main fruit rot showing up on the fruit. Growers should protect the fruit. Birds eating the fruit are still a major problem.
Grapes veraison continues. Color has been developing slowly, but there few green berries left in many vineyards. This cool weather will probably delay harvest. Niagara harvest was scheduled to begin September 7 with Concord harvest following 10 days later. The second generation of grape berry moth is flying and stings in fruit can be found. Growers should be scouting hot spots and the edges of their vineyards for stings and other signs of recent berry moth activity. Most of the activity seems to be on the edges of vineyards. Grape leafhopper numbers are building. Phomopsis symptoms are easy to find in most grape vineyards. Downy mildew is showing up in susceptible varieties.
Southwest Michigan Grape Growing Degree Days form April 1, through Sunday August 15, 2004. |
|
Location |
Grape GDD |
1796 |
|
Bainbridge |
1839 |
Lawton: |
|
Hartford |
1681 |
Grand Junction: |
1886 |
1552 |
|
In Strawberries, now is a good time to fertilize new growth in strawberry. 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 picking up. With the wet weather growers should be protecting their fruit from botrytis fruit rot.
