Integrated Crop Management News

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Consider 15-inch Row Spacing in Soybean

February 22, 2018
graph showing row spacing.

Row spacing is a management decision that often comes up as a priority for achieving high-yielding soybean. Research across the Midwest over several years has consistently shown that soybean planted in narrow rows (<30 inches) has a yield advantage compared to wide rows (≥ 30 inches). The primary reason for this advantage is light utilization; canopy closure is approximately 15 days earlier in 15-inch rows compared to 30-inch rows. Canopy closure earlier in the growing season results in greater light interception and higher growth ra

Frogeye Leaf Spot Fungicide Resistance Confirmed in Iowa Soybean

February 19, 2018
Frogeye leaf spot is a common foliar disease in Iowa, appearing as gray lesions surrounded by a reddish-brown border on soybean leaves.

Plant pathologists at Iowa State University and University of Kentucky have confirmed that isolates of Cercospora sojina, the pathogen that causes frogeye leaf spot of soybean, have shown resistance to quinone outside inhibitor (QoI, strobilurin) fungicides in Iowa.

Should We be Spraying Fungicides on Corn at V12?

February 8, 2018
graph of humidity at ISU research farms

In 2017, we tested several foliar fungicides on corn 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 (AEA) Farm, Boone.