Submitted to: Phytopathology
Publication Type: Proceedings
Publication Acceptance Date: 2/18/2002
Publication Date: 6/19/2002
Citation: KEINATH, A.P., HARRISON JR, H.F. INCREASE IN POPULATIONS OF RHIZOCTONIA SOLANI AND WIRESTEM OF COLLARD WITH VELVETBEAN COVER CROP MULCH. 2002. PHYTOPATHOLOGY 92:5150 Interpretive Summary:
Technical Abstract: Traditional non-chemical methods for managing soilborne pathogens are crop rotation and cover crops. However, increases in soilborne pathogens and root diseases are disadvantages of legume cover crops. Velvetbean was grown as a summer cover crop, then disced into the soil or killed with herbicide and left in place as an organic mulch. Plots not planted to velvetbean served as a fallow control. Collard was transplanted in October 2000 and 2001. Incidence of wirestem caused by R. solani was determined visually and populations of R. solani were estimated by wet-sieving soil and culturing organic debris on ethanol-KNO3 medium. In both years, killed cover crop mulch increased populations of R. solani compared with fallow (less than 0.01) and increased wirestem incidence over the other two treatments (less than 0.01 in 2000 and less than 0.05 in 2001). Recovery of R. solani was greater in the disced plots than in the fallow plots in 2000 but not in 2001. If velvetbean is used as a cover crop, it should be disced into the soil before transplanting collard to reduce the risk of wirestem.