ARS | Publication request: CROP ROTATION AND COVER CROP EFFECTS ON SOILBORNE DISEASES OF POTATO

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: May 15, 2006
Publication Date: July 30, 2006
Citation: Larkin, R.P., Griffin, T.S., Honeycutt, C.W. 2006. Crop rotation and cover crop effects on soilborne diseases of potato. Phytopathology. CD-ROM

Technical Abstract: Seven different 2-yr rotations, consisting of barley/clover, canola, green bean, millet/rapeseed, soybean, sweet corn, and potato, all followed by potato, were assessed over an 8-yr period for their effects on the development of soilborne potato diseases and soil microbial communities. These same rotations were also assessed with and without the addition of a fall cover crop of no-tilled winter rye over a 3-yr period. Canola and rapeseed rotations consistently reduced Rhizoctonia diseases (stem canker and black scurf) and common scab (25 to 38% reduction) and resulted in increased microbial activity and unique soil microbial profiles. Addition of the rye cover crop further reduced black scurf and common scab, averaging 12.5 and 7.2% reduction, respectively, across all rotations. The combined effect of a canola or rapeseed rotation and winter rye cover crop reduced disease severity by 35 to 41% for black scurf and 20 to 33% for common scab relative to continuous potato with no cover crop. Addition of a cover crop also significantly affected soil microbial characteristics and improved tuber yield (4% increase). Thus, in addition to positive effects in reducing erosion and improving soil quality, cover crops in conjunction with effective crop rotations, can provide improved control of soilborne diseases.