Simulating the U.S. Impacts of Alternative Asian Soybean Rust Treatment Regimes

Abstract

Asian soybean rust (rust) is an emerging issue in U.S. crop production and was identified in nine states during 2004. Recent farm surveys indicate that many producers are adjusting their management practices to the possibility of a rust infestation. The economic and environmental impacts of such adjustments are not known in the medium run given these new developments. We combine 2005 data on the geographical distribution of the fungal pathogen that causes rust with 2005 information on the availability and material costs of fungicides to analyze three treatment strategies. Our results indicate a higher range of economic impacts than previous research has indicated, but are consistent with earlier findings indicating that rust infestations will likely result in reduced soybean production, reduced exports, and higher prices.

Crop Disease and Agricultural Productivity

“…In contrast, V. wilt cannot be treated once crops are aected. Existing work on crop disease, such as Johansson et al (2006) and Gomez, Nunez, and Onal (2009) on soybean rust, and Atallah et al (2015) on grapevine leafroll disease, focuses on spatial issues regarding the spread of the disease. In contrast, V. wilt has only a limited geographic impact, and thus dynamic considerations are more important than spatial ones for V. wilt.…”

A Market-based Mitigation Program for Wind-borne Diseases

“…5 Moreover, mitigating infestation can contribute to 4 We acknowledge that payments under this system could go to producers who would have implemented curative or preventive methods on their own without additional incentives. However, Johansson et al (2006) and Livingston (2010) provide evidence that welfare losses associated with producers failing to properly manage invasive species outbreaks are large and likely outweigh the potential costs of providing fungicide to producers who are already managing disease spread. Moreover, because the checkoff structure requires a mandatory, actuarially fair payment from each producer, fungicide applications may become more effi cient if producers begin using preventive methods only when the likelihood of infestation is greatest.…”

“…The thirteenequation system that defi nes the market is shown in equations (1A) through (13A) of the Appendix (available from the authors) and the associated variables are defi ned in Table 1. Equations (A12) and (A13), reproduced here, show how damage 13 See Johansson et al (2006), Bekkerman, Goodwin, and Piggott (2008), and Roberts et al (2009) for an overview of soybean rust's pathological characteristics and disease effects within the United States. For examples and descriptions of other wind-borne diseases in the United States, see Roelfs (1989), Palm (2001), Davis (1987), and Shiyomi and Koizumi (2001).…”

“…Initial losses and losses after spread are the same because farmers apply curative fungicide after fi nding a soybean rust infestation Johansson et al (2006). simulated yield losses under various treatment scenarios and Livingston (2010) estimated those yield losses, and both studies showed that curative actions resulted in an average 7 percent yield loss.…”

Epidemiological studies of shading effects on Asian soybean rust

“…As we have shown, Asian soybean rust (ASR), caused by Phakopsora pachyrhizi, is considered the most threatening disease in major soybean-producing regions worldwide JOHANSSON et al, 2006;IVANCOVICH, 2005;KRISHNA and NAIK, 2001). In Brazil, early-season disease onset usually resulted in severe defoliation and yield losses when environmental conditions were favorable for epidemic development .…”