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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Publications at this Location » Publication #201556
Title: EFFECTS OF ORGANIC AND CONVENTIONAL PRACTICES ON WEED CONTROL IN A PERENNIAL CROPPING SYSTEM

Author
item Baumgartner, Kendra
item Steenwerth, Kerri
item VEILLEUX, LISSA - FORMER USDA ARS EMPLOYEE

Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/12/2006
Publication Date: 1/15/2007
Citation: Baumgartner, K., Steenwerth, K.L., Veilleux, L.M. 2007. EFFECTS OF ORGANIC AND CONVENTIONAL PRACTICES ON WEED CONTROL IN A PERENNIAL CROPPING SYSTEM. Weed Science. 55:352-358.

Interpretive Summary: We evaluated the efficacy of an organic weed control practice (soil cultivation with a Clemens cultivator) and applications of the herbicide, glyphosate, for controlling vineyard weeds. Experimental treatments (winter-spring glyphosate, spring cultivation, fall-spring cultivation, fall cultivation-spring glyphosate) were carried out in a California wine grape vineyard for three years. Cultivation alone was not as effective as glyphosate, based on lower weed biomass in the glyphosate-only treatment in two of three years. However, given that two passes with the Clemens cultivator decreased weed biomass relative to one pass, it is possible that additional passes could bring about further reductions. Pairing fall cultivation with glyphosate was as effective at reducing weed biomass as two glyphosate applications in two of three years, suggesting that substituting a glyphosate application with cultivation may be an effective method of reducing herbicide use in vineyards. Multivariate statistical analysis revealed significant differences in the weed species that predominated cultivated or glyphosate-treated vineyard rows, especially in the ‘spring cultivation’ treatment. Based on our findings of high relative abundance of field bindweed and sowthistle species, which are problematic vineyard weeds that grow into the vine canopy and disrupt canopy management practices, it is possible that either the presence of soil disturbance or the absence of herbicides favored these species.

Technical Abstract: Vineyard weed communities were examined under the influence of an organic weed control practice, soil cultivation with a Clemens cultivator, and applications of the herbicide, glyphosate. Experimental treatments (winter-spring glyphosate, spring cultivation, fall-spring cultivation, fall cultivation-spring glyphosate) were carried out in a California wine grape vineyard for three years. Cultivation alone was not as effective as glyphosate, based on lower weed biomass in the glyphosate-only treatment in two of three years. However, given that two passes with the Clemens cultivator decreased weed biomass relative to one pass, it is possible that additional passes could bring about further reductions. Pairing fall cultivation with glyphosate was as effective at reducing weed biomass as two glyphosate applications in two of three years, suggesting that substituting a glyphosate application with cultivation may be an effective method of reducing herbicide use in vineyards. Canonical correspondence analysis revealed significant treatment effects on community structure. Weed composition in the ‘spring cultivation’ treatment was significantly different from that of all other treatments. Based on our findings of high relative abundance of field bindweed and sowthistle species, which are problematic vineyard weeds that grow into the vine canopy and disrupt canopy management practices, it is possible that either the presence of soil disturbance or the absence of herbicides favored these species.