Central Michigan vegetable regional report – July 13, 2016
Tomato and potato growers should be protecting crops with fungicides to prevent late blight.
July 13, 2016 - Author: Fred Springborn, Michigan State University Extension
Air temperatures in Entrican, Michigan, ranged from the upper 70s to upper 80s for highs this week. Low temperatures ranged from the mid-50s to mid-60s. Average relative humidity levels have been in the mid-60s to low 70s until this week. Humidity levels have increased with several days averaging in the mid-80s to low 90s. Rainfall totals were variable with most areas receiving at least an inch of rain this week and several areas receiving over 3 inches.
Many potato fields are blossoming and setting tubers. Colorado potato beetle summer adults are emerging. While there have been no reports of late blight in our region as of July 13, late blight has been reported in Branch County. We also have an abundance of volunteer potatoes scattered around in rotation crops and volunteers can be observed growing for rock piles. These potatoes increase the risk of late blight being present, as they are not protected by fungicide applications and may be a scoured of inoculum as late blight was present in the area last season.
Michigan State University Extension advises all growers use the highest labeled rate of preventative fungicides on a seven-day schedule. For late blight, in the last 10 days we have recorded 18 disease severity values, four in the last 24 hours. Visit Michigan Late Blight Risk Monitoring for more details.
Early sweet corn plantings are tasseling with harvest likely to begin in 10 days. Western bean cutworm flight has begun with traps catching relatively low numbers this week.
Pea harvest is ongoing for roadside markets. Processing peas in the area are being harvested this week.
Summer squash harvest is in its second week for many growers. Powdery mildew is becoming established in most plantings.
Pickling cucumber planting continues. No downy mildew has been observed or reported in the area yet, but growers should be on the lookout for this disease and apply preventative fungicides.