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.

Mid-Season Soybean Diseases: Scouting and Management

July 30, 2010
Soybean white mold

XB Yang, Department of Plant Pathology

This is another unusual growing season, with a cool and wet spring followed by the hot and rainy summer. The cool weather that continued into the first week of July suddenly changed when a heat wave accompanied with rainy days arrived. The hot and wet final two weeks of July remind me of the subtropical weather in the Gulf Coast of Louisiana where I did my graduate study and where foliar diseases are a major issue in crop protection each year.

Crop Minute Week of July 26

July 28, 2010

In this week's crop minute Alison Robertson, ISU Extension field crops pathologist discusses application of foliar fungicides on corn.

Check Soybean Roots for SCN Females

July 26, 2010
Field with slight stunting and yellowing (in the background)

Yield loss caused by soybean cyst nematode (SCN) does not always result is symptoms, especially in cool and wet growing seasons. The only way to check for SCN in the field is to dig roots and look for SCN females. This also is a useful way to check how well SCN-resistant varieties are controlling the nematode.

Nematodes Damaging Corn This Year?

July 19, 2010
Root zone of plants showing possible symptoms of nematode damage

Symptoms of injury to corn from feeding by plant-parasitic nematodes includes yellow leaves, stunting of plants, and mid-day wilting. To determine if nematode feeding is responsible for crop injury symptoms observed in the field, soil and root samples must be collected and sent to a qualified laboratory for testing.

Late Summer Seeding of Forage Crops

July 19, 2010

Late summer can be an excellent time to establish forage crops and seed thin or bare spots in spring established forage stands, provided there is sufficient moisture for germination and good seedling growth.

Green Cloverworms Appear in Soybean

July 12, 2010
Sub-economic defoliation caused by green cloverworm

Higher than normal numbers of green cloverworm are being reported in central Iowa. The last major green cloverworm outbreak in Iowa was in the 1970s.

Summary: Foliar Fungicide on Corn in Iowa (2007 - 2009)

July 7, 2010

Data from corn fungicide small plot trials conducted by Iowa State University faculty and staff, and on-farm trials conducted by the Iowa Soybean Association On-Farm Network, the ISU Corn and Soybean Initiative and the ISU Northwest On-Farm research program were recently collated and summarized.