Pumpkin management in the final stretch
The evidence of proper management shows up now. Some issues can still be addressed, but others required attention months ago. Poor control of Powdery Mildew will result in defoliation, sunburned fruit and weak, brown handles. There is limited effectiveness with rescue sprays for powdery. Fruit rots are triggered in some fields by August rains. This is usually caused by a Phytophthora population in the field.
Southwest Michigan vegetable update
Producers are having difficulty controlling late season diseases.
West central Michigan vegetable update
For cucurbits, the high rainfall is likely going to cause an uptick in Phytophthora fruit rots in winter squash. Prioritize parts of fields that do not have apparent symptoms for harvest and try your best to keep harvest crews out of identifiable hot spots. Remember that fruit can be asymptomatic (not showing rot) but infected, and subsequently rot in the crib. Monitor sanitizer levels in wash water to reduce the risk of spread amongst fruit if they are going into dunk tanks or are sprayed with recirculated water.
Flint, Michigan, area urban agriculture update
Growers are battling wet fields after recent heavy rains, impeding crop harvest. Area growers are harvesting summer squash (zucchini, yellow) and winter squash (including acorn, butternut, delicata, spaghetti and kabocha).
Southeast Michigan vegetable update
In pumpkins, powdery mildew is starting to take out the vines in some plantings. If you are losing foliage and fruit is orange, it is better to harvest now than to let fruit sit and get sunburned. The fruit isn’t going to get any larger, so get the pumpkins harvested and store them somewhere shady and dry until it’s time to sell.
Areas that have gotten more rains recently are seeing some fruit rot. If you are in a field with phytophthora that has become more pronounced in recent weather conditions, harvesting is especially important—harvesting is a better control strategy than trying to do a phytophthora spray (even if using a top-of-the-line product). If harvesting to combat this disease, start in the driest, cleanest and least impacted areas, then move into the wetter areas. Keep an eye on the pumpkins as you have them stored, you likely harvested some pumpkins in the early stages of infection that will meltdown post-harvest, which will infect adjacent pumpkins.
East Michigan vegetable update – Sept. 5, 2018
Vine crop growers across the region are faced with a combination of three issues: rapid powdery mildew defoliation, fruit rots and early ripening fruit. We are two weeks ahead with most crops this year. For more information on pumpkin management, see my article, “Pumpkin management in the final stretch.”