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Submitted to: American Peanut Research and Education Society Proceedings
Publication Type: Abstract Only Publication Acceptance Date: 7/13/2006 Publication Date: 9/22/2006 Citation: Johnson, W.C. 2006. Progress report: Weed management in organic peanut production [abstract]. In: Proceedings of the American Peanut Research and Education Society Annual Meeting, July 11-14, 2006, Savannah, GA. 38:90. Interpretive Summary: Technical Abstract: Studies have been conducted in Tifton, GA since 2003 to develop weed management systems for organic peanut production. Trials in conventional tillage production systems evaluated row patterns, cultivation, and remedial weed management using propane flaming, clove oil, and citric acid. Weed control and peanut yields did not differ betwen row patterns, despite quicker canopy closure from peanut seeded in narrow rows compared to wide rows. This was attributed to extreme difficulty in cultivating peanut seeded in narrow rows. Annual grasses were not controlled by any of the remedial treatments. Dicot weeds were initially controlled by propane flaming and clove oil, but the lack of residual weed control allowed subsequent weed emergence. Peanut yields were very low in all plots, due to poor control of annual grasses. Additional trials were conducted in reduced-tillage systems. Systems evaluated were strip-tillage and no-tillage, remedial weed control (pelargonic acid, propane flaming), and handweeding. Overall, weed control was better in no-tillage plots than in strip-tillage plots due to less soil disturbance that stimulated weed emergence. Senesced crimson clover was mowed prior to planting peanut which released crimson clover seed. The resulting crimson clover seedlings appeared to suppress weed emergence. Pelargonic acid killed clover seedlings, resulting in subsequent weed emergence. Furthermore, pelargonic acid did not control annual grasses. Handweeding once or twice was not sufficient to control weeds and peanut yields were poor. Preliminary results from these trials clearly show that weed control in organic peanut production will be difficult and costly, with the inability to manage annual grasses a limiting factor. In conventional tillage systems, successful weed control depends on stale seedbed tillage, frequent cultivation, and handweeding. In reduced tillage systems, peanut planted no-till in crimson clover appears to offer the best early-season weed suppression of the treatments evalauted. Remedial weed control using propane flaming, pelargonic acid, and clove oil extract are cost-prohibitive and too narrowly focused to be useful in organic peanut production. Current research is evaluating blind cultivation with a flex-tine cultivator, corn gluten, and mulching materials to suppress weeds. |
