Dan Pavuk

Weather
This has been an interesting season for vegetable production in Southeast Michigan! In terms of weather, this was one of the coolest summers on record. The cooler temperatures slowed development of vine crops, sweet corn, and tomatoes, but more typical temperatures and higher humidity levels in August helped these crops mature. As I write this report, tomatoes are still being harvested on many farms, which is a bit behind a more typical year. Rainfall was also lacking in many areas for extended periods of time, and this resulted in extensive use of irrigation by commercial growers.

Crop report season summary
As in recent years, cucurbit downy mildew once again appeared in Monroe County before any other location in the state. Unfortunately, this disease will likely continue to be an issue for both commercial growers as well as smaller operations in the coming years.

Other vegetable diseases also made appearances, too. Leaf blight of tomato became problematic, mostly in home gardens and smaller production operations, as did Septoria leaf spot of tomato. Effective preventative fungicides are available for control of late blight, early blight, and Septoria leaf spot of tomato, and few problems were observed in commercial operations where these fungicides were utilized. Powdery mildew always attacks squash and pumpkin each year, and it seemed as if this disease was showing up a little earlier than usual this season.

What about insect pests of vegetables? European corn borer numbers recorded in pheromone traps were consistently low this year. Small populations of this pest may be due to the widespread use of Bt field corn, which has decreased the abundance of the corn borer. Corn earworm was slow to arrive, but large numbers did occur in August at several locations. This insect will inevitably become a problem in sweet corn late in the season unless it is controlled by insecticides every three to seven days, depending on how many are captured per week in pheromone traps. Japanese beetle did not seem to be as abundant this year as in past years. Other pests, such as diamondback moth and imported cabbageworm on crucifers, had to be controlled on some farms. Variegated cutworm did not become a significant pest on tomatoes, and squash vine borer populations remained low during the season. Cucumber beetles were locally abundant on some farms, and since these vector the bacterium that causes bacterial wilt of muskmelon and cucumbers, they had to be controlled.

In spite of the unusual summer with regards to the weather, yields of all vegetable crops appeared to be very good in the southeastern Michigan region. Farmers’ markets, roadside stands, CSAs, and large commercial growers all seemed to have good harvests. There is nothing quite like fresh, locally grown vegetables in the summer!

I want to take this opportunity to thank all of the vegetable growers who allowed me to operate insect monitoring traps on their farms this summer. This is an important contribution to our understanding of the life histories of these pests, and such understanding allows for the development of more effective control.
Have a great fall season!


Downy mildew infection in a cucumber planting.


Septoria leaf spot of tomato.


Striped cucumber beetle.


Corn earworm.