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.

Algorithms Used to Update State Soil Survey

February 10, 2020
soil survey map pages

While seasonal weather can be the difference between a good and a bad harvest, it is the soil that moderates the long-term productivity of a field. The inherent properties of soils are vital to know when it comes to management practices on any agricultural landscape.

The state of Iowa has the agricultural economy that it does largely because of its soils. Iowa relies on soil for so many different things, the list can be overwhelming at times and includes crop production, water management, and land valuation.

Instances of Frogeye Leaf Spot Resistance to QoIs Abundant in Iowa

January 27, 2020
frogeye resistance map of counties in Iowa

Iowa State University researchers, with funding from soybean checkoff through the United Soybean Board and Iowa Soybean Association, have confirmed that over 70 isolates of the pathogen Cercospora sojina (cause of frogeye leafspot in soybeans in Iowa) are resistant to quinone outside inhibitor (QoI) fungicides.

Summary of Foliar Fungicide Applications on Gray Leaf Spot and Yield of Corn in Iowa in 2019

January 27, 2020

This article summarizes our 2019 corn foliar fungicide trials that were done at six locations in Iowa: ISU Northwest Research and Demonstration Farm (NWRF), Sutherland; Northeast Research and Demonstration Farm (NERF), Nashua; Northern Research and Demonstration Farm (NRF), Kanawha; Southwest Research and Demonstration Farm (SWRF), Lewis; Southeast Research and Demonstration Farm (SERF), Crawfordsville; and the Ag Engineering and Agronomy Farm (AEA) near Boone.

Summary of 2019 Insecticide Evaluations for Soybean Pests

January 13, 2020
Soybean aphid colony

The 2019 growing season was challenging for farmers in many parts of the state, especially because cold and wet soil conditions in April significantly delayed planting. Thistle caterpillar was the most abundant insect statewide, though multiple species of caterpillars, Japanese beetle, soybean aphid, and soybean gall midge were observed in soybean.

Income in SCN-infested Fields Can Be $200 Per Acre Less With PI 88788 Than With Peking Resistance

January 9, 2020

The soybean cyst nematode (SCN) has been managed for decades with resistant soybean varieties. Almost all soybean varieties have SCN resistance from a breeding line named PI 88788, and SCN populations have developed high levels of reproduction on the PI 88788 resistance. The results of a field experiment in southeast Iowa in 2019 foreshadow alarming yield loss due to SCN in the future if farmers continue to have only PI 88788 SCN resistance available in soybean varieties.