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United States Department of Agriculture

Agricultural Research Service

Title: Corn gluten meal: Weed control and yields for onions

Authors
item Webber, Charles
item Shrefler, James - OSU, LANE, OK

Submitted to: Oklahoma Agriculture Experiment Station Departmental Publication
Publication Type: Experiment Station
Publication Acceptance Date: May 20, 2006
Publication Date: June 1, 2006
Citation: Webber III, C.L., Shrefler, J.W. 2006. Corn gluten meal: Weed control and yields for onions. 2005 Vegetable Weed Control Studies, Oklahoma State University, Division of Agricultural Sciences and Natural Resources, Department of Horticulture and Landscape Architecture. Stillwater, OK. MP-162, p. 21-22.

Interpretive Summary: Producers in Oklahoma are becoming interested in sweet onions as an alternative crop for farm diversification, but onions are very sensitive to competition from weeds. Early weed competition can greatly decrease onion yields and uncontrolled weeds can result in the total loss of marketable onions. Certified organic onion producers have a tremendous need for organic materials that can reduce weeds in onions early in the growing season. One weed control option for certified organic producers is corn gluten meal (CGM). Field research was conducted in southeast Oklahoma (Lane, OK) at the USDA, ARS, South Central Agricultural Research Laboratory to determine the effectiveness of CGM for weed control in transplanted onion production. The research involved 8 different weed control treatments applied to the spring transplanted onion, 'Candy.' Just prior to transplanting onion seedlings on March 17, 2005, CGM was applied by hand, spreading the dry material at 2 rates (2.0 lb/100 ft2 and 8 lb/100 ft**2) and either incorporated into the surface 1-2 inches or left on the soil surface. Each incorporation method also had a weedy-check (weeds allowed to grow) and weed-free (handweeded) treatment. Onion seedlings were transplanted in two rows on raised beds with 36 inches between rows. Bulbs were harvested June 28, 2005, 103 days after planting, sorted by size, counted, and weighed. Weed control ratings (grass weed control, broadleaf weed control, and total weed control), total weed cover, and weed composition were collected throughout the growing season. Total weed control increased for both incorporation methods as amount of CGM increased. The incorporated weedy-check and weed-free treatments produced greater yields than the non-incorporated treatments, while incorporating the CGM decreased total yields compared to CGM treatments receiving no incorporation. This research indicates CGM will help control weeds, but higher amounts of CGM should be used. The organic producers will also increase yields and weed control by not incorporating CGM. This research will be repeated during the 2006-growing season to further evaluate the influence of corn gluten meal on weed control and onion yields.

Technical Abstract: One weed control option for certified organic producers is corn gluten meal (CGM). Field research was conducted in southeast Oklahoma (Lane, OK) to determine the efficacy of CGM as an herbicide for use in transplanted onion production. The research involved 8 weed control treatments with 4 replications applied to the spring transplanted onions, 'Candy.' Just prior to transplanting onion seedlings on March 17, 2005, CGM was applied by hand, spreading the dry material at 2 rates (2.0 lb/100 ft**2 and 8 lb/100 ft**2) and either incorporating into the surface 1-2 inches or left on the soil surface. Each incorporation method also had a weedy-check (weeds allowed to grow) and weed-free (handweeded) treatment. Onion seedlings were transplanted in two rows on raised beds with 36 inches between rows. Bulbs were harvested on June 28, 2005, 103 days after planting, sorted by size, counted, and weighed. The sorted onion grades included "small" (less than 2 inches), "medium" (2.0 to 3.25 inches), "large" (3.25 to 4.0 inches), and "colossal" (greater than 4.0 inches) for marketable quality. Split and decomposed onions were unmarketable. Weed control ratings (grass weed control, broadleaf weed control, and total weed control), total weed cover, and weed composition were collected throughout the growing season. This experiment had very high weed pressure with multiple species of broadleaf and grass weeds. In weedy-check treatments, grass and broadleaf composition ranged from 37 to 40% for grasses, and 60 to 63% for broadleaf weeds. Total weed control increased for both incorporation methods as CGM rates increased. Application of CGM resulted in a shift in weed composition compared to the weedy-checks. As CGM controlled broadleaf weeds, the grass weeds increased growth. Incorporation methods had a significant impact on total marketable onion yields. The weedy-check with incorporated CGM and weed-free treatments produced greater yields than the non-incorporated treatments; while incorporating CGM decreased total yields compared to CGM treatments receiving no incorporation. This research will be repeated during the 2006 growing season to further investigate the impact of CGM on weed control and yields in transplanted onions.

Last Modified: 9/22/2014
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