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Soybean losses due to diseases and nematodes in the USA since 1996: General trends and observations

Paul Esker: Penn State University

<div>Since 1996, losses due to soybean diseases including nematodes have been collected by experts in the USA from 28 soybean producing states. During this period, numerous technological advances have occurred in soybean production, ranging from the advent of GMO soybean to the discovery of soybean rust, as well as increased use of different seed treatment and foliar fungicide products. The objective of the current work was to estimate the overall impact of soybean diseases, as well as examine how losses due to specific variables have changed over time. First, the overall loss for each state and year was estimated using Padwick’s calculation. Second, annual soybean price data was obtained from USDA-NASS to estimate the economic impact of individual diseases and nematodes for each state and year combination. Temporal trends were examined based on heat maps, and physical losses (i.e., yield) were calculated to re-estimate yield, which were compared empirically to current yield in consult with soybean agronomists. In the northern region, losses ranged from 10 to 17%, while in the southern region, losses ranged from 7 to 14%. Economically, losses on a per hectare basis were judged to be between $48 and $351 in the northern region, and $32 and $116 in the southern region. Overall, losses have been variable across states, depending on the year, although results illustrate the extreme importance and impact of soybean pests and diseases on production in the USA.</div>