SW Michigan Fruit Update
July 11, 2006
Weather
Temperatures the last two weeks were in the 70s and 80s with lows in the 50s and 60s. Scattered rain fell July 3 and July 9 with rainfall totals of one to three tenth reported but most areas received less than a tenth of an inch of total rain in the last two weeks. Scatter hail was reported on July 3. Topsoils are very dry and growers are irrigating. Soil temps are in the 70s. This week’s forecast is for hotter weather with highs in the 90s and chance of thunderstorms. The GDD below are from the Enviroweather site. In the last two weeks we picked up 375 GDD base 42, 330 base 45 and 275 base 50. In the coming week we will pick up 300 GDD base 42, 250 base 45 and 200 base 50.
Southwest
Michigan Growing Degree Day Totals
|
Grapes, from April 1 |
|||
Location |
GDD 42 |
GDD 45 |
GDD 50 |
GDD 50 |
1935 |
1645 |
1214 |
1184 |
|
1887 |
1588 |
1150 |
1118 |
|
1955 |
1677 |
1228 |
1194 |
|
1758 |
1496 |
1075 |
1047 |
|
1992 |
1693 |
1249 |
1208 |
|
South Haven (April 1) |
1593 |
1344 |
972 |
972 |
1969 |
1670 |
1236 |
1199 |
|
1778 |
1487 |
1065 |
1047 |
|
General Insect Activity
Japanese beetles numbers have increased but not as dense as in the past few years. Expect more beetles to emerge after a good rain. Few fruit flies such as cherry fruit fly, apple maggot and blueberry maggot are out. More will emerge after we get some rain. The second generation of oriental fruit moth is emerging. Codling moth trap catches are down and the first generation flight should be over. We expect the second generation to emerge this week or next. Red-banded and Oblique banded leafrollers are out. Tarnished plant bug activity is declining. You can use the Enviroweather site GDD model for some pests if you know its emergence or Biofix at your site.
Tree fruit
Apricots
are being harvested.
Peach fruit are coloring. Queencrest was harvested last week. Harbinger and PF1 are being harvested.
The second generation of oriental fruit moth is emerging. Trap numbers are up sharply this week. Egg hatch of the second generation of OFM should begin this week. Biofix in Northern Berrien County for the second generation was probably about July 7 at 1540 GDD base 45. First egg hatch in Southern Berrien County for the second generation was probably about June 29 at 1330 GDD base 45. The dry weather is helping thrips. Peach orchards near mowed fields should be protected from tarnished plant bug.
Sweet cherry harvest is winding down. Brown rot was reported in several areas, but no severe outbreaks were reported.
Tart cherry harvest is in full swing. Growers need to protect against cherry leaf spot after harvest.
Plumsare coloring.
Apple fruit are about 2 inches in diameter. Oriental fruit moth trap catches are up signaling the beginning of the second generation. Codling moth trap catches are down and the first generation flight should be over. We expect the second generation to emerge this week, and egg hatch to begin at about another 1250 GDD past Biofix about 1578 GDD base 50. Obliquebanded leafroller egg hatch continues. OBLR Biofix was June 12 at 1150 GDD base 42 and egg hatch should end 1000 GDD after Biofix (2150 GDD). European red mites populations have exploded in some orchards and bronzing can be seen. Five to seven mites per leaf is the treatment threshold for European red mite in July. Apple maggot has been trapped in Southern Berrien County. Fungicides to reduce sooty blotch and flyspeck should be included in cover sprays. Leaf drop due to scab in common in unsprayed orchards. Fire blight shoot strike symptoms are reported to be less in orchards treated with Provado. Shoot strike is when the bacteria are carried from infected shoots to healthy shoots by leafhoppers.
Pear fruit are attacked by second-generation codling moth.
Small fruit
Blueberry harvest
continues with Duke and other early varieties. Anthracnose fruit rot is the
main disease concern now. Alternaria fruit rot is more a disease of over ripe
fruit. Cane collapse due to phomopsis
is common. Japanese
beetles are out. Cherry fruitworm and cranberry fruitworm larvae are
damaging the fruit. Blueberry
maggot flies are scarce. Rain or irrigation should bring these flies out.
Growers should be scouting for leaf
rollers and tussock moth
larvae.
In Grapes are at or past berry touch. Grape berry moth larvae are feeding in the clusters. Grape leafhoppers are scarce. Phomopsis leaf lesions are common in most plantings. Black rot and downy mildew are appearing. Grape scouting reports can be found at the MSU Grape recourses page at www.grapes.msu.edu.
Strawberry renovation has been completed in most fields. Potato leafhopper burn was common in many fields. Be prepared to treat for this pest to prevent stunting of the new growth.
Raspberry harvest is underway. Growers should be scouting for Japanese beetles. Monitor pre harvest intervals (PHI) for fungicide and insecticide sprays.
Cranberry bloom continues.
Miscellaneous
The last Grape IPM meetings will be held in Berrien and Van Buren Counties on Thursday, July 13. The morning meeting will be from 10 AM to noon at the Cronenwett Farm Shop at 70123 28th Street east of Lawton. The afternoon meeting will be at the Southwest Michigan Research & Extension Center from 2 to 4 PM. There will also be a twilight grape IPM scouting IPM meeting July 20 at Bob Dongvillo's farm, south of Benton Harbor.
