Southeast Michigan vegetable regional report – May 29, 2013

Rain showers and humid weather in the past week can be conducive to disease outbreaks. Protect your crops, especially on fields with disease history.


Our area had 1.37 inches of rain in four rain events in the past week. Temperatures in the southeast ranged from 44 to 82 degrees Fahrenheit with an average of 55 F. In the following week, temperatures are forecasted to range from 55 to 84 F, with 44 to 84 percent chance of rain from Friday to Sunday (May 31-June 2).

Beware that pathogens prefer rainy, overcast and humid weather, just like the weather conditions we experienced in the past week and are in the forecast for next week. Fields with history of Phytophthora spp. diseases that are planted with susceptible crops such as cucurbit crops (cukes, melons, pumpkins, etc.) and solanaceous crops (tomatoes, peppers, eggplant, etc.) should be protected with efficacious fungicide application. Visit the Phytophthora fact sheets from Michigan State University Extension plant pathologist Mary Hausbeck’s lab to see current recommendations.

Downy mildew spore counts remain low but present in the spore traps. Remember to scout your plants regularly for early downy mildew symptoms. Downy mildew can infect and cause symptoms on young plants, even in cotyledons. Cucurbits raised in tunnels can be protected with fungicide (Fluopicolide) treatment through the drip. Consult the MSU Extension bulletin E0312, “Nematode, Insect and Disease Control” (online or paper copy), and the MSU Extension fact sheet “Monitoring and Managing Cucurbit downy mildew” for more information.

The growing degree days (GDD) recorded at the Petersburg Enviro-weather station indicated the current year is behind by 63.1, 52.5 and 37.8 GDD base 42, 45 and 50 F (see table below).

Growing degree day (GDD) summary (data summarized from Enviro-weather)

Enviro-weather station

Current GDD base

42 F

45 F

50 F









Commerce Township








Average of stations in this region




Average five years Petersburg station




Vegetable crops report

Field operation continues, but was delayed by the rain of the previous days.

Peas are flowering, while green beans and snap beans are behind or just planted. Cole crops such as cabbage, broccoli and radishes continue to grow. Radish planting continues. No damage caused by cabbage maggots has been observed.

Get ready to scout for caterpillars that cause damage in cole crops. To learn more about them and how they differ, check out MSU Extension specialist Zsofia Szendrei’s bulletin “Caterpillar pests in cole crops” (online or paper copy) that compares caterpillars. The bulletin comes in handy when scouting your cole crops and provides decision-making thresholds.

Early planted sweet corn continues to grow and planting continues. According to insectforecast, low risk of corn earworm is forecasted to move from the southern states. However, this risk is more relevant for tomatoes in high tunnels that are reaching first fruit set. Pheromones traps can be used to monitor adults and scout for tomato damage.

Tomato and pepper transplanting to the field continues.

Related Events

Related Articles

Related Resources