Research Accomplishment Reports 2007

Multi-state Activity Monitoring Soybean Rust

D. Hershman
Department of Plant Pathology

 

Project Description

Soybean rust (SBR) is potentially a devastating disease in North America. Field-level epidemics are sporadic and regional-level epidemics are rare, so far. However, it is extremely important to monitor the U.S. soybean crop for SBR occurrence so that producers can implement effective fungicide management programs, when needed. Kentucky has participated in the North American SBR monitoring effort since 2005. In 2007, the total monitoring effort for soybean rust in North America involved the establishment of more than 700 sentinel plots across 41 states and five Canadian provinces. The University of Kentucky extension plant pathologist coordinates SBR surveillance activities in the southern U.S., and is chairman of the IPM-PIPE steering committee, which oversees SBR surveillance activities in the U.S. Soybean rust was successfully monitored in North America during 2007. The network also provided occurrence data for other soybean pests, in addition to soybean rust. These data have been fed into existing national data bases, including NAPIS.  Data were also used in refining SBR predictive models, which is a research focus of the sentinel network. SBR monitoring activities were extensive in Kentucky during 2007 and the disease was monitored in both soybean and kudzu (alternative host). In 2007, this activity involved 52 individuals (crop consultants, industry agronomists, agricultural extension agents, state extension specialists and soybean growers). SBR was detected in Kentucky late in the season, but too late in the season to justify spraying.

Impact

Past SBR monitoring activities in North America, in general, and in Kentucky, specifically,  have been very successful. As a result, soybean producers have a high level of confidence in the monitoring activites. They trust the output of the sentinel network to let them know when to spray and when not to spray fungicides for soybean rust management. In 2007, it is estmated that $207M was saved in the U.S. by soybean producers not spraying a fungicide for SBR management on 28.76M acres. In Kentucky, we estimate that 400,000 acres were not sprayed with a fungicide as a direct result of SBR monitoring efforts. At an estimated cost of $18/ac, that represents a savings in Kentucky of $7.2M. Data were supplied to soybean rust disease forecast researchers for use by modelers in refining existing models for SBR.