Southwest Michigan vegetable regional report – August 31, 2016
Okay! Enough! Let’s go back to dry conditions for a while.
We have had 9 to 16 inches of rain in August across southwest Michigan, which has caused some issues with harvest and pest control activities. Even after the rain has stopped, field activity was delayed in some locations due to standing water and muddy fields. Growers have had to discard over-mature fruit or have missed some pesticide applications at critical times.
Vine crop growers are now seeing signs of downy mildew. Powdery mildew is also prevalent. Michigan State University Extension advises pumpkin growers to be especially diligent in their spray applications. Pumpkin leaves and handles still need protection from powdery mildew. A good leaf canopy is also important in preventing sunburn. Even mature, orange fruit will sunburn. If the fruit is mature and the vines are dying down, fruit should be harvested and placed under cover. Virus symptoms can be observed in many fields. Squash bug numbers remain low.
Bacterial diseases are increasing in tomato fields.
Rust has been found in some sweet corn fields. Applying control depends on harvest date. Generally, infection occurs late enough in the life of the planting that harvest will occur before significant yield losses. An increase in corn earworm infestation has also been observed, most likely resulting from poor timing of pesticide applications during a rainy period earlier in the month.