SW Michigan Fruit Update
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Southwest
Michigan, June 23, 2009
Weather
Last week’s weather was warm and wet. High temperatures rose from the 70s into the high 80s. Lows were generally in the 60s. Rain fell Tuesday and Wednesday, leaving about a third to a half inch. Major storms crossed the region Friday (June 19). High winds, heavy rain and some hail caused scattered damage in many areas. Rainfall totals for the week were in the 2 to 3 inch range. Soil moisture levels are high. We still lag in heat accumulation for the growing season but this week’s forecast of high temperatures near 90 should put us close to normal. Very warm conditions are expected to continue through the week.
Southwest
Michigan Growing Degree Day Totals
|
Grapes, from April 1 |
|||
Location |
GDD 42 |
GDD 45 |
GDD 50 |
GDD 50 |
1317 |
1088 |
750 |
730 |
|
1194 |
975 |
653 |
647 |
|
You can find weather and
IPM information for Southwest Michigan at the Enviroweather website.
Insects
Eastern cherry fruit fly was trapped this weekend. Rose chafers numbers should peak this week. False Japanese beetles are out. This beetle looks like a small Japanese beetle but lacks the white tufts of hair either side of its abdomen. Potato leafhopper activity has increased. We expect obliquebanded leafroller egg hatch to begin this week. San Jose scale crawlers should be out.
Tree fruit
Apricot fruit are about 2 inches in diameter and early varieties are starting to color.
Peach fruits are about 1¾ inches in diameter and growers are finishing hand thinning. Rusty spot can be found. We expect to begin trapping Oriental fruit moth of the second flight this week. Lesser peach tree borers are flying and growers should apply trunk sprays for borers soon.
Sweet cherry harvest should begin later this week. Birds continue to eat ripening fruit. Fruit cracking due to Friday morning’s rain was a problem. Growers need to protect sweet cherry fruit from brown rot. Fruit brown rot has already been reported and Friday’s rain and warm temperatures where a severe infection period for brown rot and cherry leaf spot. Cherry fruit flies were caught this week. Insecticides should be applied to late variety cherries which will be on the trees long enough 7 to 10 days) for this pest to develop.
Tart
cherries are coloring and only a few green fruit can be found. Friday’s
storm broke down trees, broke branches, blew down fruit and bruised fruit remaining in the
trees. The hot temperatures forecast for this week are too high to apply
Ethrel. Cooler temperatures are forecast for late in the week so growers should not
be in a hurry to apply Ethrel under hot conditions. ‘Balaton’ cherries are
coloring. Eastern cherry fruit
fly was trapped this weekend in northern Berrien County. Yellowing of the cherry
leaves due to cherry leaf spot
or bacterial canker is more
noticeable. Yellowing due to sour cherry yellows virus is also apparent.
In Plums, European plums are 20 mm in diameter. We are still seeing fruit drop and pit hardening underway. Oriental plums are over an inch in diameter. Only the most vigorous shoots are still growing so growers can reduce fungicides to control black knot.
Apple fruitlets are generally 1.5 inches in diameter. Fruit drop continues. Hail damage from Friday’s storm was reported but this damage is light. Apple scab on fruit and leaves is relatively common. Enough hours of wetness have accumulated since petal fall that sooty blotch and flyspeck can develop. Fungicides to reduce leaf scab, sooty blotch and flyspeck should be included in alternate cover sprays. Fireblight symptoms continue to spread. Some orchards are severe. Large branches are wilting and browning. Many growers were out spraying streptomycin following Friday’s severe thunderstorms, which probably spread the disease to new trees. We should see new fireblight symptoms from this storm in a week to ten days. Growers should also focus controls on sucking insects such as aphids and leafhoppers, which can spread the bacteria to new trees. Codling moth trap catches are up with a strong flight. We should see a corresponding surge in egg hatch a week from now. Codling moth Biofix was May 20 for most of the region and many growers are applying their second sprays. We have accumulated about 500 GDD since codling moth Biofix and should be at peak egg laying. For obliquebanded leafroller, we have accumulated about 335 GDD base 42 since Biofix on June 8. We expect obliquebanded leafroller egg hatch to begin mid week when we reach 400 to 450 GDD after biofix. Stippling from white apple leafhoppers and hopper burn from potato leafhoppers are becoming more common. Green apple aphid numbers are building in terminals. European red mites numbers are building. The treatment threshold for European red mite in late June and early July is 5 mites per leaf. Oriental fruit moth trap should start again this week with the emergence of the second generation. Apple maggot emergence is forecast for June 29 and we normally catch our first apple maggot fly around the beginning of July. Apple maggot traps should be out.
Pear fruit are 1.5 inches in diameter. Pear Psylla numbers are building. Pear psylla is the only pest of interest at this time.
Small fruit
Blueberries fruit are pea sized. A significant amount of
green fruit was blown off the bushes by the strong winds last Friday. Growers should
maintain protection against anthracnose
fruit rot. Flight of the cherry
fruitworm and cranberry
fruitworm is ending and we are seeing injury in the fields now. Blueberry
maggot emergence is forecast for June 28 and blueberry maggot traps should be
out. We are finding small leafroller
larvae in some fields. Virus disease symptoms have been easy to find. Look
at the Michigan Blueberry IPM Newsletter posted by Paul Jenkins at the Berry Entomology Lab.
Grape bloom continues. Bloom in Concord and most French hybrid grapes is winding down. Vinifera grapes are in full bloom. Phomopsis leaf lesions are easy to find in most vineyards. Rose chafers are out but are not numerous enough to treat in most situations. Grape berry moth laravae have been found feeding in the grape clusters. At this time these larvae cause little real damage to the crop. Grape berry moth sprays should wait until the end of bloom. Be sure to include fungicides to control the young fruit clusters from disease. Grape Leafhopper adults can be found. See the most recent copy of Grape IPM Newsletter at the MSU Grape current conditions webpage. Here is a link a table of SW Michigan’s Grape Growing Degree-Days from April 1 to June 21, 2009. This Thursday, June 25, there will be a grape IPM meeting from 6 PM to 8:30 PM.
Strawberry harvest continues but may end quickly in this week’s heat. The heat will cause fruits to ripen quickly. Renovation should begin as soon as harvest ends.
Raspberry harvest is beginning. Cane tip wilt due to girdling by the raspberry cane borer has appeared. The female moth cuts two parallel rings on current years growth during egg laying. Growers can scout and cut out these tips to help manage this insect. Fungicides should be applied to protect the fruit and suppress leaf diseases. We expect Japanese beetles to appear soon.
Miscellaneous
This Thursday, June 25, there will be a grape IPM meeting from 6 PM to 8:30 PM. The location is Tim Seppala’s vineyard on County Road 354, between 26th Street and CR 652 Southeast of Lawton. Dinner will be provided and this meeting is good for one RUP credit.
The last Monday Fruit IPM Update meeting will be Monday June 29, at the Fruit Acres Farm in Berrien County.
