Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/22/2007
Publication Date: 9/17/2007
Citation: Wrather, A.J., Shannon, G., Mengistu, A. 2007. Soybean planting date effects on soil population density of Macrophomina phaseolina. Plant Health Progress. http://plantmanagementnetwork.org. Interpretive Summary: Charcoal rot is a disease of soybean caused by the fungus (mold) Macrophomina phaseolina. This disease ranked within the 10 most economically important soybean diseases in the USA during 2003-2005. Planting date can affect the severity of some soybean diseases. A field experiment was conducted during 2000-2004 to determine the effects of soybean planting date on the population of this fungus present in the soil. Planting date did not affect the number of the fungus present in the soil. These results suggest that soybean producers should not be concerned about planting date directly affecting the amount of charcoal rot expected in any one year.
Technical Abstract: A field experiment was conducted during 2000-2004 near Portageville, MO to determine the effects of soybean planting date on the soil population density of Macrophomina phaseolina. The site was planted to cotton the previous 10 years. The planting dates were mid-April, mid-May, and mid-June during 2000-2003, and plots were in the same location each year. Soil samples from the top 15-cm soil layer were collected from plots during May each year and analyzed for the population density of M. phaseolina. Planting date did not affect the soil population density of M. phaseolina, but the differences in soil population density among years were significant. These results suggest that soybean producers should not be concerned about planting date directly affecting M. phaseolina soil population densities.