Modeling the Severity-Yield Relationships in Soybean Frogeye Leaf Spot Epidemics
| Autor: | Jhonatan Barro, Emerson Medeiros Del Ponte, Tom Allen, Jason P. Bond, Travis R. Faske, Clayton Hollier, Yuba Raj Kandel, Daren S. Mueller, Heather M. Kelly, Nathan Michael Kleczewski, Keith A. Ames, Paul Price, Edward Sikora, Carl Bradley |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Plant Disease. |
| ISSN: | 1943-7692 0191-2917 |
| DOI: | 10.1094/pdis-03-23-0440-re |
| Popis: | Frogeye leaf spot (FLS), caused by Cercospora sojina, is an important foliar disease affecting soybean in the United States. A meta-analytic approach including 39 fungicide trials conducted from 2012 to 2021 across eight states (Alabama, Arkansas, Illinois, Iowa, Kentucky, Louisiana, Mississippi, Tennessee) was used to assess the relationship between FLS severity and soybean yield. Correlation and regression analyses were performed separately to determine Fisher's transformation of correlation coefficients (Zr), intercept (β0) and slope (β1). Disease pressure (low severity = ≤34.5 and high severity = >34.5%) and yield class (low = ≤3,352 and high = >3,352 kg/ha) were included as categorical moderators in the model. The Pearson’s r ̅, obtained from back-transforming the Z ̅r estimated by an overall random-effects model, showed a significant negative linear relationship between FLS severity and yield (r ̅ = -0.60). The Z ̅r was affected by disease pressure (P = 0.0003) but not by yield class (P = 0.8141). A random-coefficient model estimated a slope of -19 kg/ha for every % severity for a mean attainable yield of 3,719.9 kg/ha. Based on the overall mean (95% CI) of the intercept and slope estimated by the random-coefficients model, the overall relative damage coefficient was estimated to be 0.51% (0.36-0.69), indicating that a percent increase in FLS severity would result in a 0.51% yield reduction. The best model included yield class as a covariate and population-average intercepts differed significantly between low (3,455.1 kg/ha) and high (3,842.7 kg/ha) yield classes. We also estimated economic damage thresholds for a range of soybean prices, control costs and fungicide efficacies. As expected, the threshold values increased as the control efficacy also increased and were affected by different crop prices and fungicide simulated costs. The current results highlight the potential impact of FLS on soybean yield if not well managed and may be helpful in disease management decisions by applying fungicides before disease severity reaches economic damage thresholds. |
| Databáze: | OpenAIRE |
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