Central Michigan vegetable update – July 18, 2018
Dry weather pests become the focus now that we have gone from feast to famine on rainfall.
Lack of rainfall has become the weather story in central Michigan, as much of the area has received less than a half-inch of rainfall over the past few weeks. Air temperatures have generally been above normal with highs in the 80s up to the lower to mid-90s for much of the period. Potential evaporation rates have been high and many crops are depleting the once excessive soil moisture and are now showing signs of drought stress.
Early planted sweet corn is nearly ready for market on several farms in the area. Western bean cutworm flight is under way. Monitor pre-tassel sweet corn for western bean cutworm egg masses.
Potatoes are growing moderately well considering the very warm temperatures. Disease pressure has been relatively low with no reports of late blight from scouts. Variegated cutworm has been observed in many fields at low to moderate numbers. Variegated cutworm is an aerial feeder and typically does not “cut off” stems as some of the other cutworms do.
Pickling cucumber planting continued this week with the late planting. There have been no reports of downy mildew.
Pea harvest continues and is finished on many farms. There have been reports of aphid infestations in this crop.
Dry beans are flowering and setting pods. Closely monitor snap beans that were planted without an insecticide seed treatment for potato leafhopper in the coming weeks.
Summer squash harvest is underway. Powdery mildew is starting to appear on many older plantings.
Monitor for thrips and twospotted spider mites in the coming weeks as the dry weather persists. Also, monitor potato leafhoppers, tarnished plant bugs and other Hemipteran pests, as succulent, irrigated vegetable crops may become very attractive as the alternate host plants in the surrounding landscape dry down.