Southeast Michigan vegetable regional report – July 9, 2014

Weather has been conducive for the development of plant diseases. Scout and submit samples of suspected late blight of tomatoes and potatoes, and for cucurbit downy mildew.

Posted on July 9, 2014 by Lina Rodriguez Salamanca, Michigan State University Extension

Weather

In the past week, rainfall recorded in the southeast averaged 0.89 inches. The Petersburg Enviro-weather station recorded 0.15 inches of rain while the Commerce Township recorded 1.38 inches. Air temperatures in the southeast have ranged from 44 to 87 degrees Fahrenheit, with mostly cloudy to partly cloudy days. Up to 15 humid hours were recorded at the Petersburg station in the last week. Based on the average of the southeast weather stations, we currently have reached 1,111 growing degree days base 50 degrees F (GDD50).

Table 1. Rainfall and regional degree days (DD) for the SE region. (http://www.cnchemicals.com/)

Weather outlook

Temperatures are forecasted to range from 54 to 85 degrees F over the next week, with low chances of rain (ranging from 10 to 30 percent) Thursday to Saturday, and increase chance of rain for Sunday to Tuesday (July 13-15).

Vegetable crops

Harvest of cabbage and broccoli continues. Cabbage head rot is prevalent in some fields with low laying areas. Harvest is ongoing for small acreage of kale, mustards greens, lettuce, kohlrabi, red beets, beans (lima and wax) and Swiss chard.

Angular leaf spot symptoms in pumpkin leaf. Photo credit: Lina Rodriguez Salamanca, MSU Extension

Symptoms of angular leaf spot were confirmed in pumpkins. Pumpkins’ and melons’ (watermelon and muskmelons) fruit development continues. Harvest of cucumber, zucchini and yellow squash continues. Spotted and striped cucumber beetles continue to be active in the area. To learn about how to scout and determine treatment threshold in muskmelons, Purdue’s Monitoring and Decisionmaking for Cucumber Beetles on  Muskmelon. No significant influx of spores has been detected at the Monroe cucurbit downy mildew (CDM) trap, but influx has been detected in the Saginaw trap. No CDM has been detected at this time in the area. However the epidemic in the county continues with the most recent report out of Delaware. Scout for CDM symptoms and submit any suspicious symptoms to Extension educators or the MSU diagnostic lab as early detection is critical.

Peppers are bearing 2 to 3 inch fruit, no thrips infestation have been observed in peppers at this time. Scout for aphids as populations tend to increase at this time of year. Early blight and foliar bacterial diseases continue to be problematic in fresh market tomatoes.

No late blight has been reported in Michigan, but a report was confirmed from Indiana. When scouting, keep in mind symptoms in tomato and potato. Contact Michigan State University Extension educators with vegetable responsibilities (listed below) if late blight is suspected.

• Ron Goldy (.(JavaScript must be enabled to view this email address)), Southwest Michigan Research & Extension Center (South West MI) based in Berrien County
• Lina Rodriguez Salamanca (.(JavaScript must be enabled to view this email address)), Southeast MI, based in Lenawee County
• Ben Werling (.(JavaScript must be enabled to view this email address)), West Central (Kent, Mason, Muskegon, Newago, Oceana, Ottawa Counties) based in Oceana County
• Ben Phillips (.(JavaScript must be enabled to view this email address)) Bay area, based in Saginaw County
• James Dedecker (.(JavaScript must be enabled to view this email address)) Presque Isle County
• Hal Hudson (.(JavaScript must be enabled to view this email address)), Tuscola County
• Terry McLean (.(JavaScript must be enabled to view this email address)), Genessee County
• Fred Springborn (.(JavaScript must be enabled to view this email address)), Montcalm County

Early sweet corn harvest will begin soon. One and three corn earworm (CEW) moths were caught in the last 7 days in the Monroe County traps in the last week. Three western bean cutworm moths were caught today. No European corn borer (ECB) moths have been caught in the Monroe traps this week.

For more information on commercial vegetable production, contact Lina Rodriguez Salamanca at 517-264-5310 or at .(JavaScript must be enabled to view this email address).

This article was published by Michigan State University Extension. For more information, visit http://www.cnchemicals.com/. To contact an expert in your area, visit http://www.cnchemicals.com/, or call 888-MSUE4MI (888-678-3464).