Do fungicides make sense for oats and barley in northern Michigan?

Farmers are interested in the yield impact fungicides have on oats and barley, and MSU personnel are trying to find out.

Oats and barley continue to be important feed, rotation and cash crops in Michigan, with 30,000 acres of oats and 8,000 acres of barley harvested statewide in 2011. Current strong commodity prices may encourage farmers in areas not well-adapted to corn and soybean production to consider producing more small grains as cash crops. Oat acreage planted in 2011 decreased about 50 percent in Michigan from 2010, presumably due to the economic opportunities presented by higher value cash crops. Oats and barley, as well as wheat, are of special interest in the northern areas of Michigan where cropping opportunities are limited by climate and soils.

A field trial to assess yield impact of using fungicides on oats and barley was conducted in 2011 at the MSU Upper Peninsula Research Center in Chatham, Mich. Excel oat plots were sprayed with Twinline and Caramba fungicides at a growth stage of Feekes 10.3 (heads mostly emerged). Rasmussen barley plots were sprayed at Feekes 10.4 with Twinline, Prosaro and Caramba fungicides. Unsprayed plots were also included. Visual ratings of disease on flag leaves were taken twice later in the growing season. Average yields of the plots were excellent, with oats averaging 109 bushels per acre and barley averaging 65 bushels per acre.

Weather played a role in the outcome of the trial. From planting date to harvest, 65 percent of the days were above average temperature. GDD42 accumulation for the period of July 10 through August 22 (harvest) totaled 1,177 compared to the six-year average of 1,073 (including 2011). Total rainfall from planting to harvest was down 1.28 inches from the six-year average. Rainfall from June 23 - August 22, 2011, was down a whopping 2.69 inches compared to the six-year average. Generally, despite a cold, wet spring, the weather was warm and very dry, especially in the later stages of barley and oat development. This environment did not encourage development of fungal disease.

Once all the plot yields were recorded and analyzed, it became clear that there were no statistical differences between sprayed and unsprayed plots.

Results of this one-year trial did not show any yield benefit from spraying fungicides on oats and barley after head emergence. The growing conditions for the trial, while excellent for oat and barley production, were not favorable for disease development. Typically, crop trials need to be conducted over multiple years to be meaningful, and this one is a case-in-point. The hot, dry weather during July and August in Chatham, Mich., was great for oats and barley, suppressing fungal disease development. Fungal disease may be more prevalent during a more “normal” year. Plans are underway to repeat the trial in 2012.

A complete report can be viewed at 2011 MSU Extension Barley and Oat Fungicide Trial.

For more information, contact MSU Extension educator Jim Isleib at 906-387-2530.

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