Insect activity has increased in the past week. Cabbage caterpillars have reached threshold in some fields while cutworms and armyworms are active and causing damage in several vegetable crops.
Posted on June 4, 2014 by Lina Rodriguez Salamanca, Michigan State University Extension
Weather
In the past week, rainfall recorded in Southeast Michigan averaged 0.45 inches. The Michigan State University Petersburg Enviro-weather station recorded 0.03 inches of rain while the MSU Commerce Township Enviro-weather station recorded 1.38 inches. Air temperatures in the Southeast have ranged from 45 to 85 degrees Fahrenheit with mostly sunny days.
Based on the average of the Southeast Michigan Enviro-weather stations, we currently have reached 495 growing degree days (GDD) base 50 F, behind by 85 GDD when compared with the five-year average. The current year heat accumulation is similar to the 2009 growing season.
Regional GDD for the Southeast Michigan region via MSU Enviro-weather.
|
Enviro-weather station
|
GDD 42
|
GDD 45
|
GDD 50
|
|
Petersburg
|
862
|
710
|
495
|
|
Commerce Township
|
757
|
616
|
418
|
|
Romeo
|
790
|
642
|
436
|
|
Hudson
|
844
|
697
|
488
|
|
Average for region
|
813
|
666
|
459
|
Weather outlook
A cooler week is ahead with temperatures forecasted to range from 46 to 78 F over the next week. There are low chances of rain, ranging from 10 to 20 percent, Thursday through Saturday, June 5-7, with an increased chance of rain Sunday through Tuesday, June 8-11.
Vegetable crops
Cabbage and broccoli are starting to form heads and curds. Cabbage maggot damage has been observed in radishes and cabbage, being more serious in radishes. Some fields have reached treatment thresholds for cabbage caterpillars, including diamondback moth and imported cabbage worm. Flea beetles were observed in broccoli and cabbage fields above threshold numbers, which are two to five beetles per plant according to Michigan State University Extension. Parsley and cilantro fields continue to grow while Mustard greens and radish harvest continues.
Cabbage maggot damage in radishes (left) and diamondback pupae on cabbage foliage (right). Photo credit: Lina Rodriguez Salamanca, MSU Extension
Sweet corn planting continues, but emergence has been compromised by the low soil moisture. Some armyworm and cutworm damage has been observed in sweet corn and cutworm damage has been observed in cabbage, pumpkin and pepper fields, but the number of worms per field remains low.
Cutworm that was observed in peppers. Photo credit: Lina Rodriguez Salamanca, MSU Extension
Early planted potatoes are bearing flower buds. So far no Colorado potato beetles have been observed this week, but they have been observed in other areas of the state. As predicted by the Michigan Late Blight Risk Forecasting website, volunteers are present in fields planted to potatoes in 2013.
Harvest of tomato in high tunnels continues while lower foliage has gray mold symptoms, and some damage in green fruit caused by worms has been observed. Early planted processing tomato fields are starting to bear flowers, while recently transplanted tomatoes show some drought and wind stress. Transplanting of banana and jalapeño peppers continues.
Cucumbers in hoophouses continue to be harvested while cucumbers in the fields are bearing 1- to 3-inch fruit. Yellow squash and zucchini plants are bearing 4-inch fruit and harvest will start in the next couple days. Striped cucumber beetles are present in fields in low numbers, less than one beetle per 30 plants, and minimal damage has been observed. Cucumber, squash, zucchini, cantaloupe, watermelon and pumpkin planting continue.
String beans have high numbers of bean beetles with damage ranging from 25 to 30 percent. Swiss chard harvest continues, but leaf miners are causing trouble in this crop.
Leaf miner in Swiss chard. Photo credit: Lina Rodriguez Salamanca, MSU Extension
For more information on commercial vegetable production, contact Lina Rodriguez Salamanca at 517-264-5310 or .(JavaScript must be enabled to view this email address).
This article was published by Michigan State University Extension. For more information, visit http://www.cnchemicals.com/. To contact an expert in your area, visit http://www.cnchemicals.com/, or call 888-MSUE4MI (888-678-3464).