ARS | Publication request: Enhancing Potato System Sustainability: Soilborne Diseases and Soil Microbial Communities

Submitted to: Northeast Potato Technology Forum Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: March 10, 2008
Publication Date: March 13, 2008
Citation: Larkin, R.P., Honeycutt, C.W., Griffin, T.S., Halloran, J.M., Olanya, O.M., He, Z. 2008. Enhancing Potato System Sustainability: Soilborne Diseases and Soil Microbial Communities. Northeast Potato Technology Forum Abstracts. CD-ROM.

Technical Abstract: Four different potato cropping systems, designed to address specific management goals of soil conservation (SC), soil improvement (SI), disease suppression (DS), and a status quo (standard rotation) control (SQ), were evaluated for their effects on soilborne diseases of potato and soil microbial community characteristics (SMCC). SQ consisted of barley underseeded with red clover followed by potato (2-yr). SC featured an additional year of forage grass and reduced tillage (3-yr, barley/timothy-timothy), SI added yearly compost amendments, and DS featured diverse crops with known disease-suppressive capability (3-yr, mustard/rapeseed-sudangrass/rye). Each system was also compared to a continuous potato control (PP) and was conducted under irrigated and non-irrigated conditions. In both the 2006 and 2007 potato years (and after a full rotations cycle), the DS, SI, and SC rotations all reduced stem canker (by 20-50%) relative to PP, and DS and SC reduced black scurf and common scab. Overall, the DS system, utilizing Brassica and other disease-suppressive rotation and cover crops, resulted in the lowest disease levels for all three soilborne diseases observed (canker, black scurf, and common scab). The SI system, characterized by yearly compost amendments, resulted in the greatest effects on soil microbial parameters, including greater microbial populations and activity, as well as higher yields, but also resulted in greater levels of common scab. Irrigation also resulted in increased yield, but also higher levels of common scab. The distinct and consistent effects of the rotations on soil microbial characteristics observed may be related to and have implications on the development of disease suppression and crop productivity and are being further investigated.