Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: June 20, 2007
Publication Date: July 28, 2007
Citation: Larkin, R.P., Griffin, T.S., Olanya, O.M., Starr, G.C., Honeycutt, C.W. 2007. Effects of Different Soil and Crop Management Strategies on Soil Microbial Communities and Soilborne Diseases of Potato. American Phytopathological Society Abstracts. Vol. 97(7): S61, 2007 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 standard rotation control (SR), were evaluated for their effects on soilborne diseases of potato and soil microbial community characteristics (SMCC). SR 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. At the end of the first full rotation cycle (3 yrs), the SC, SI, and DS rotations significantly reduced stem and stolon canker (21-51%) relative to SR and PP. All rotations reduced black scurf relative to PP, and scurf was lower in SI than all other rotations (28-58% reduction). Irrigation significantly increased common scab, whereas SC and DS rotations reduced scab. SI resulted in higher bacterial populations and microbial activity, but also high levels of common scab. Each rotation resulted in distinctive changes in SMCC as represented by microbial populations, substrate utilization, and FAME profiles.