Regional reports on Michigan vegetables – July 18, 2012
MSU Extension educators’ pest and vegetable updates for Michigan.
This week’s regional reports:
- Southwest Michigan – Ron Goldy
- Central Michigan - Fred Springborn
- Southeast Michigan – Lina Rodriguez Salamanca
Weather was again extremely hot and dry. Highs ranged from 89 to 97 F and lows from 64 to 73 F. There were spotty showers across the area with amounts ranging from 0.0 to over 0.5 inches. At the Southwest Michigan Research and Extension Center (SWMREC) we have only had 0.75 inches of rain since June 1 and have had 22 days over 90 F since May 1. Generally, we only have 12 all season. Conditions continue extremely dry with non-irrigated fields showing significant stress.
Tomato and cantaloupe harvest has begun and bell pepper harvest will start this week.
The weather continues to cause problems with fruit set and growth for many crops. Flowers are falling off beans and the remaining pods are small at maturity. Fruit set is a problem in vine crops. Watermelon plantings have some early set fruit, but then have a gap due to lack of bee activity and out of balance male/female flower numbers.
Zucchini and yellow squash have a lot of misshapen fruit due to poor pollination. Mites are a problem on watermelon, tomatoes, potatoes, eggplant and other crops. Early plant senescence is occurring in potatoes. Growers should expect smaller fruit size on tomatoes and other crops as the hot temperatures cause them to ripen faster. They should also plan for an earlier end to the season.
More root disease issues are occurring since growers tend to over-irrigate in these situations. Soil moisture levels need to be allowed to drop before irrigating again and it is better to have more short irrigation periods than one long period.
Scattered thunder showers this morning (July 18) brought some relief to several parts of the region. Reports of 0.75 to over 1 inch are being reported. The south edge of the region continues to miss the significant rains and drought stress is very evident, especially in Ionia and Kent counties and areas to the south.
High air temperatures ranged from the upper 80s to 100-plus over the past week. Low air temperatures were in the upper 50s to mid-70s. Soil conditions remain quite dry in many areas as the rains we have gotten have not been adequate to replenish soil moisture for long; evapotranspiration rates have been high in most crops. Irrigation has been running for much of the week in nearly all crops where irrigation is available.
Potato tubers continue to develop rapidly. Vines in some fields are collapsing sooner than what is optimal. Colorado potato beetles are present in all life stages. Potato leafhopper adults and nymphs are present in significant numbers – higher than last week.
Summer squash and zucchini harvest is continuing with fruit growing rapidly.
Pickle harvest is underway with fruit developing rapidly. Uneven development of fruits has been a concern in some fields.
Western bean cutworm pheromone trap catches are tapering off in some traps this week with my trap here in Stanton, Mich., catching five to six per night verses 30 to 40 moths per night last week. We continue to catch low numbers of corn earworms.
Southeast Michigan – Lina Rodriguez Salamanca, Michigan State University Extension
Monroe and Lenawee counties did not have any significant rain event in the past week. The counties in southeast Michigan have moderate drought according to the U.S. drought monitor, while Wayne County has only abnormal dryness.
Temperatures remained high; the maximum by day was between 87.1 and 96 F and the minimums being from 46.5 to 58 F. Relative humidity at the Hudson Enviro-weather station ranged from 22.9 to 92.4 percent with three to 10 hours of wetness.
Crops and pests
Pollination and abundant fruit set has been observed in cucurbit crops. Cucurbit fruit harvest continues. Powdery mildew has been observed in zucchini and yellow squash. One squash vine borer moth was found on the Washtenaw County trap, while none were found on the Monroe County trap.
In the Monroe County spore trap, cucurbit downy mildew counts remain steady with counts of seven to 13 spores per day. Cucurbit downy mildew has been reported in Michigan.
Tomatoes and peppers are bearing fruit; development and ripening seem to be slow. Spotted wing Drosophila traps are in place in Monroe and Lenawee counties. The risk for late blight remains low in our area. See the Late Blight Risk Monitoring website to get personalized recommendation based on you planting date.
Cabbage harvest continues and some new fields are being planted.
Sweet corn harvest continues. Risk of western bean cutworm is high in our area. This means that adults are migrating from the south according to www.insectforecast.com. The count of insect pests in the traps was five corn earworms and four western bean cutworms.
Monitoring will continue. Keep up to date with the count at Corn earworm in sweet corn trapping map for July 9-15, 2012.