Soybean aphids, two-spotted spider mites, fungicide decisions despite little disease pressure, and the hot and dry conditions were some of the more common issues or questions Iowa State University Extension and Outreach Field Agronomists have seen or heard about in fields across the state over the last week. Read on for more specifics about what’s happening around the state.
Northwest Iowa
While the story of the "haves" and "have nots" continues across the state, some areas in NW did finally get some much-needed rain early this week. And unfortunately, the Zearing area in Central Iowa also had some hail damage. Some of the observations or questions coming in from the field this last week have been on or have included: spider mites, new counties in Iowa found to have soybean gall midge, soybean aphids, tar spot, SDS, and potato leafhoppers.
Scouting for spider mites in field crops is encouraged with prolonged dry conditions. Twospotted spider mites can increase whenever temperatures are greater than 85°F, humidity is less than 90 percent, and moisture levels are low. These are ideal conditions for the twospotted spider mite and populations are capable of increasing very rapidly.
The past week brought again spotty rainfall across the state. With the dry conditions and warmer temperatures forecasted there are concerns about what this may mean for the crops. Spider mites, corn rootworms, grasshoppers, aphids, and weed escapes were other observations or concerns coming from the fields this last week. Read on for more specifics about what’s happening in fields across the state.
Northwest Iowa
With parts of northern Iowa now being in a D3 or extreme drought and other areas on the drought monitor expanding, the drier conditions are a concern with what impact they are having on the crops as well as forage availability. Other concerns coming from the field this past week included spider mites as well as corn rootworms. Read on for more specifics about what’s happening in fields across the state.
Northwest Iowa
Corn rootworms, spider mites, soybean gall midge, and the hot and dry conditions were common questions or issues received or observed by ISU Extension and Outreach field agronomists this past week. Read on for more specifics about what’s happening around the state.
Northwest Iowa
Twospotted spider mites have been spotted in fields across much of Iowa already this summer, as much of Iowa is in moderate or severe drought (D1-D2, US Drought Monitor). I encourage you to scout for twospotted spider mites in crops. Twospotted spider mites can increase whenever temperatures are greater than 85°F, humidity is less than 90 percent, and moisture levels are low.
The hot and dry conditions this past week resulted in crops showing more signs of stress, especially in the drier parts of the state. Drought stress, spider mites, corn rootworms, and questions regarding fungicide applications were the big questions or issues observed by ISU Extension field agronomists this past week. Read on for more specifics on what's happening in different regions across the state.
Northwest Iowa
Rainfall still eludes most of the state of Iowa, and drought has continued to envelope the state, with the driest areas expanding from the west central part of the state. Crops continue to go downhill in the drought and the derecho areas, especially with the warmer temperatures of this week.
According to the U.S. Drought Monitor, southeastern and south central Iowa are experiencing prolonged heat and moisture stress. In early August, there were twospotted spider mites detected in corn and beans. I recommend scouting corn and soybean fields for mite infestations this month, especially in these areas.
