SW Michigan Fruit Update
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Southwest Michigan Fruit Update, July 10, 2007
Weather
The last two weeks have been hot and dry. Highs have been in the upper 80s and 90s and lows have risen from the 60s into the 70s. Unirrigated crops and lawns have dried up. Fruit crops are also showing signs of drought stress, shedding older leaves, setting terminal bud and slowing fruit growth. Soils are very dry and soil moisture reserves are low. The forecast is for a chance of thunderstorms.
Southwest
Michigan Growing Degree Days (GDD) Totals
|
Grapes from April 1 |
|||
Location |
GDD 42 |
GDD 45 |
GDD 50 |
GDD 50 |
2231 |
1934 |
1482 |
1365 |
|
2156 |
1861 |
1417 |
1319 |
|
2099 |
1811 |
1373 |
1273 |
|
2030 |
1743 |
1308 |
1211 |
|
2240 |
1950 |
1495 |
1375 |
|
2170 |
1879 |
1431 |
1318 |
|
1989 |
1706 |
1280 |
1187 |
|
1967 |
1682 |
1253 |
1173 |
|
Insects
Japanese beetles and potato leafhopper are very common. San Jose scale crawlers are out and settling on fruit. We are catching peach tree borer and now is the time to apply trunk sprays.
Tree fruit
Peaches are coloring and the harvest of early varieties such as PF1, PF5B and EarlyStar are underway. Oriental fruit moths trap catches are falling so the second generation of Oriental Fruit Moth has peaked. It was biofixed for June 18 (1353 base45) and egg hatch should end at about 2180 GDD base45 or about 10 days. Growers have been applying peach tree borer trunk sprays, which should be applied soon for maximum benefit. Bacterial spot symptoms on leaves and fruit are significant in a few orchards. Phomopsis constriction canker is causing flagging of current seasons growth in a few orchard. Sugar content is relatively high due to dry conditions.
Cherry harvest has ended.
Tart cherry growers should be prepared
to apply cherry leaf spot controls before the next rain.
At this time there is little sign of the disease in sprayed orchards, but there are
yellow leaves in unsprayed orchards. Post
harvest pruning of mature blocks should be done by early September.
Sweet cherry quality was excellent.
Alternaria rot (dark green fuzzy spot) was the most common fruit disorder, but was
not a significant problem.
In Plums, a few local plums are being picked. Some plum trees are collapsing apparently due to winter injury to the trunk.
Apples are 2 inches in diameter. The second-generation flight of codling moth may start soon in orchards that experienced an early flight. Other orchards that achieved good control or did not have an early flight may not see CM for several weeks. Growers should be monitoring their blocks to determine their pest levels and if they need to spray. Obilquebanded leafrollers larvae are genrally scarce. The second-generation of Oriental fruit moths is hatching. European red mites numbers are building and high in some orchards. Predator mite numbers are high in so orchards. and growers are applying controls. Aphids are common on actively growing shoots. Leaf edge burn due to potato leafhopper is easy to find. At this point in time growers are typically applying an insecticide treatment every other week, due to multiple pest emergence. Growers should include a fungicide in their next cover spray to control sooty blotch and flyspeck. Bill Shane has calculated that we have accumulated 280 hours of wetness from 10 days after petal fall and disease symptoms should appear soon.
Pear fruit are 2 inches in diameter. Pear Psylla adults are flying.
Small fruit
Blueberry harvest continues. Currently we are picking Bluecrop and demand is high. Growers are irrigating and complain they cannot keep up with the demand and maintain fruit size. Sprinkler irrigation is conducive to fruit rot development and fungicide protection is very important in these fields. Blueberry maggot is flying. Japanese beetles and blueberry aphids are out. Be sure to check the new Blueberry IPM Newsletter at the MSU Blueberry Site.
Grapes are at berry touch. Berry growth has been rapid but is slowing under the dry conditions. We past 1200 GDD last week and berries are about half of the final berry weight. Now is an excellent time to estimate harvest yields. Grape berry moth larvae are moving into the fruit. We expect second-generation flight soon. Powdery mildew in the primary disease concern but growers should maintain control for downy mildew as well. All these diseases have been found in sprayed vineyards. Japanese beetle and grape leafhopper numbers are beginning to build. The annual Viticulture Day is scheduled for July 25. See the SWMREC website for registration information. Check the MSU Grape website for scouting updates.
Strawberry growers have renovated their fields. Growers should consider Admire treatment to control potato leafhopper on renovated plants.
Raspberry harvest continues. Japanese beetles and potato leafhopper are easy to find. Early treatment will discourage feeding.
Upcoming Meetings
The next grape IPM scouting meeting will be July 12 at Bob Dongvillo's farm, south of Scottdale; and August 9 at Lemon Creek Vineyards, west of Berrien Springs. These meetings start at 6 PM. For more information on these meetings call Mark Longstroth at (269) 675-8313.
