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.

Degree Days - Cool July With Good Crop Conditions

Image of base 50 degree F degree days in regions of Iowa from May 1 to July 26, 2009

By Rich Pope, Department of Plant Pathology

Iowa corn is tasseling and silking this week. We think of the silk date as a marker for the final 60 to 65 days in which the corn reaches physiological maturity. That means we might expect dry down to extend into October across the state. Soybeans are setting pods, and with timely August rainfall, pods should fill nicely. Last week we lost approximately 50 degree days to average across Iowa, making July 2009 as one of the ten coolest in history.

Use Treatment Thresholds for Western Bean Cutworm

Image of purple western bean cutworm eggs

As adults emerge, scouting is extremely important in determining management of western bean cutworm.

Late-Season Herbicide Applications in Soybean

Weed reinfestations resulting from slow canopy development and ample soil moisture may warrant additional treatment this year.

Scout for Corn Leaf Aphids Before Tasseling

A well-timed spray while corn leaf aphids are outside the whorl or on the tassel is recommended when they exceed thresholds.

Corn Quality Issues Continue

Producers selling 2008 corn can expect closer grading and increased discount scales for damage; and they should take extra precautions to preserve the quality of 2009 crop.

Eyespot and Gray Leaf Spot Occurring in Corn

Image of characteristic lesions of eyespot

Diseases currently showing up in Iowa corn - eyespot and gray leaf spot - can result in yield loss and may increase the severity of stalk rot.

July Workshops Offer Comprehensive Corn Nematode and SCN Training

Image of past SCN training workshop

Learn about biology,scouting and management of corn nematodes and soybean cyst nematodes, and earn certified crop advisor CEUs in two-all day workshops.

It is Time to Sample for Corn Nematodes

Image of collecting soil cores

Many believe that changes in corn production practices may lead to increased damage from nematodes. Mid-season sampling is required to accurately diagnose nematode problems on corn.

Corn: Uneven Early-Season Growth Can Mean Uneven Tasseling

Regardless of reason for uneven corn growth, uneven tasseling across the field can be expected.

SCN Females Are Now Apparent on Soybean Roots

Image of adult SCN females on a soybean root and nitrogen-fixing nodules

Female soybean cyst nematodes are now present in Iowa fields. Areas of the field that favor SCN and where to look on the plant are discussed.

Pages