Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 29, 2005
Publication Date: January 18, 2006
Citation: Krupinsky, J.M., Tanaka, D.L., Liebig, M.A., Merrill, S.D., Hanson, J.D., Gulya Jr, T.J. 2006. Crop sequencing and biological control to minimize sclerotinia disease risks, 2005. Meeting Proceedings. p. 17. IN: Proc. of the 2006 Sclerotinia Initiative Annual Meeting. January 18-20, Bloomington, MN. Technical Abstract: A Crop Sequence Project evaluates the impact of previous crops (buckwheat, chickpea, corn, lentils, proso millet, grain sorghum, canola, dry pea, sunflower, and wheat) and crop residue on Sclerotinia diseases. In 2005, 400 plots of sunflower (an indicator crop) were twice evaluated for disease and harvested. The percentage of Sclerotinia basal stalk rot ranged from 0.6% for the grain sorghum (1st yr)/grain sorghum (2nd yr)/spring wheat (3rd yr)/sunflower (4th yr) crop sequence to 17% for the sunflower/sunflower/spring wheat/sunflower sequence. Crop sequences with spring wheat and grain sorghum in the 1st and/or 2nd year ranked lowest for percentage of stalk rot. The use of Coniothyrium minitans (Contans WG®) and crop sequences to reduce the risk to Sclerotinia disease was evaluated in a Biological Control Project. In 2005, the percentage of Sclerotinia basal stalk rot ranged from 0 to 18% for one study (BC02) and 0 to 15% for another (BC03). Although statistical differences among treatments were not evident, there was a trend for higher disease levels following crambe in BC03. Also, combine yield data showed a lower sunflower yield following crambe compared to the other crops. A Sclerotinia Inoculum Density Project determined the impact of sclerotia density and tillage on Sclerotinia disease severity under dryland field conditions. In 2005, the percentage of basal stalk rot on sunflower under tillage averaged 9% compared to 3% for no till. Minor differences were detected among plots with soil water measurements and analyses of soil properties indicating that the site was relatively uniform. These management practices integrated with other management options will increase the producer’s management options for reducing Sclerotinia disease risk.