Integrated Crop Management News

Links to these articles are strongly encouraged. Articles may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If articles are used in any other manner, permission from the author is required.

Predicted Corn Rootworm Egg Hatch Approaching

June 23, 2011
Accumulated degree days Jan. 1-June 21

Corn rootworm egg hatch in Iowa can occur from late May to mid June depending on soil conditions, but the average hatching date is around June 6. See date predictions for 2011.

Flooding and Stored Grain

June 22, 2011

Iowa Secretary of Agriculture Bill Northey reminded farmers in a news release June 21 that grain impacted by flood waters is considered adulterated and cannot be used for feed or food. He references this article by Charlie Hurburgh and Dan Loy.

Yellow Leaves Emerge from Twisted Whorls - 2011

June 22, 2011
Yellow leaves resulting from twisted whorls associated with an application of a growth regulator herbicide

By Roger Elmore, Department of Agronomy

Yellow leaves wave above V5 to V8 corn canopies in northern and central Iowa this week.   These sun-starved leaves freshly emerged from twisted whorls will turn green soon after they begin intercepting sunlight.

Potential causes are numerous:  rapid growth coupled with a wide range of temperatures, hail, strong winds or an application of a herbicide, insecticide or fungicide, etc. 

Oats for Forage

June 21, 2011
Three stages of oat development

By Steve Barnhart, Department of Agronomy

Oats have been an important crop in Iowa. In addition to being a favored spring-planted companion or cover crop for forage seedings, they have historically been harvested as a cash grain crop. In recent years, as market demands and cropping systems have changed, oats are more often being harvested as hay or silage for livestock.  

SCN Females Now Apparent on Soybean Roots

June 21, 2011
White, adult SCN females on soybean roots

The soybean cyst nematode (SCN) is a serious yield-limiting pest in the Midwest, and adult SCN females can be seen with the unaided eye as small, white objects on soybean roots. Recently, adult SCN females were observed on soybeans that were planted in early to mid May in north central Iowa, indicating that fields can be checked now for the presence of SCN.

Why Conservation Planning

June 15, 2011
Strip cropping on a steep slope

Conservation planning and implementation of practices need to be considered carefully as solutions to reducing potential row cropping system effects on soil and water quality.

Upcoming Workshop Spotlights Beneficial Insects

June 14, 2011

By Matt O'Neal and Kelly Semen, Department of Entomology

Farmers, researchers and native plant aficionados are invited to a one-day workshop exploring how to enhance the ecosystem services provided by beneficial insects. Iowa State University's Departments of Entomology and Natural Resource Ecology & Management, with support from the Leopold Center for Sustainable Agriculture, will host the workshop on Aug. 4.

Estimating Nitrogen Losses

June 13, 2011

One way to determine nitrogen (N) loss is to calculate an estimate. Predicting the exact amount is quite difficult as many factors affect losses. However, estimates can provide guidance for supplemental N applications.

Measuring Corn Nitrogen Status

June 13, 2011

Tools are available that can aid decisions about applying supplemental nitrogen when there have been losses of applied fertilizer or manure nitrogen.