Southwest Michigan vegetable update – June 17, 2020
Unirrigated crops are stressed as dry weather continues.
Temperatures for the week at the Southwest Michigan Research and Extension Center ranged from 71 to 87 degrees Fahrenheit for highs and 48 to 60 F for lows. The 50 F degree-day units are at 690 for 2020 compared to 565 for 2019 and 776 for the five-year average. Rainfall across the area for the week was minimal. We have had less than an inch of rain over the past three weeks. Some unirrigated sites are beginning to show stress. Soil temperatures are averaging in the mid-70s F range.
Dry weather has been good and bad. It has allowed planting and other activities to continue and has reduced disease pressure. However, direct seeded crops are planted into dry soil even in plastic, therefore, delaying germination.
Asparagus harvest is complete and growers have applied post-harvest weed control. The dry conditions will be helpful in reducing the need to control purple spot and rust, at least in the near future.
Striped cucumber beetles continue to be active in vine crops. Continue monitoring and control as needed. Harvest from low-tunnel grown cucumbers, yellow squash and zucchini will begin later this week. We have detected downy mildew spores in our trap at the Southwest Michigan Research and Extension Center but have not observed any field symptoms. Protective sprays may not be warranted at this time, but scout and apply protection at the first sign of infection. Current hot, dry weather conditions are not conducive for spread, as the disease prefers cool, cloudy, wet weather.
Earliest planted sweet corn is at tassel emergence.
Dry weather has been helpful in controlling bacterial spot on tomato. Final transplants of tomato and eggplant will go in over the next week. Staking and tying continues on tomato, eggplant and pepper.
Early potatoes are blooming.
Pea harvest began last week.
Corn borer egg masses have been observed on hops and hops downy mildew continues to be a problem.