Integrated management strategies for Phytophthora sojae combining host resistance and seed treatments

A. E. Dorrance, A. E. Robertson, S. Cianzo, L. J. Giesler, C. R. Grau, M. A. Draper, A. U. Tenuta, T. R. Anderson

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31 Scopus citations

Abstract

Phytophthora sojae has re-emerged as a serious soybean pathogen in the past decade. This may be due in part to changes in resistance levels in current cultivars, adoption of P. sojae populations to deployed Rps genes, and highly favorable environments in the past decade. This multilocation study evaluated the effect of seed treatments on the incidence and severity of Phytophthora root and stem rot on soybeans with different combinations of Rps genes and levels of partial resistance. The efficacy of the seed treatments was highly variable across locations. Seed treatments (metalaxyl and mefenoxam) provided protection and increased yields across cultivars in locations where rain or irrigation occurred shortly after planting (Ohio, South Dakota, and Ontario). However, there were no significant differences in stand or yield consistently acrosscultivars in Iowa, Nebraska, Wisconsin, or Ohio, where heavy precipitation did not occur untillater growth stages. The environment, levels of inoculum, and pathogen complex may have played a role in the different responses to the seed treatments and to the different combinations of Rps genes and levels of partial resistance to P. sojae in the cultivars. Fields that are poorlydrained and have P. sojae populations with complex pathotypes may benefit the most from seed treatments. Individual fields where producers may see the greatest benefit to utilizing these integrated management strategies will need to be identified.

Original languageEnglish (US)
Pages (from-to)875-882
Number of pages8
JournalPlant disease
Volume93
Issue number9
DOIs
StatePublished - Sep 1 2009

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ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Plant Science

Cite this

Dorrance, A. E., Robertson, A. E., Cianzo, S., Giesler, L. J., Grau, C. R., Draper, M. A., Tenuta, A. U., & Anderson, T. R. (2009). Integrated management strategies for Phytophthora sojae combining host resistance and seed treatments. Plant disease, 93(9), 875-882. https://doi.org/10.1094/PDIS-93-9-0875