ARS | Publication request: Post-directed application of potential organic herbicides for onions

Submitted to: National Allium Research Conference
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2010
Publication Date: August 31, 2011
Citation: Webber III, C.L., Shrefler, J., Brandenberger, L.P. 2011. Post-directed application of potential organic herbicides for onions [abstract]. National Allium Research Conference, December 8-10, 2010, Reno, Nevada. Available: http://www.unce.unr.edu/adhoc/narc2010/files/pdf/P-02.pdf.

Technical Abstract: Organic onion producers need appropriate herbicides that can effectively provide post-emergent weed control. Research was conducted in southeast Oklahoma (Atoka County, Lane, OK) to determine the impact of potential organic herbicides on weed control efficacy, crop injury, and yields. The experiment included 12 weed control treatments (5 herbicides at 2 rates, plus an untreated weedy-check and an untreated weed-free check) with 6 replications. The 5 herbicides and the rates included Burnout (registered trademark), 15 and 30% v/v, Matran EC (registered trademark), 5 and 7% v/v, Scythe (registered trademark), 5 and 7%, Racer (registered trademark), 9 and 12.6 v/v, and vinegar, 40 and 80 gpa). Each herbicide was applied and then reapplied after 8 days. Intermediate day, sweet onion, cv. ‘Cimarron,’ was transplanted on March 20, 2009 into 2 rows per 6 ft-wide raised beds. Each plot consisted of two onion rows per 10 ft length of bed. Matran EC produced the highest yields among treatments, but was not significantly greater than the weedy-check. Sequential-applications significantly increased weed control when comparing weed ratings at 7 days after the first herbicide application and 1 day after the second application. Scythe, Racer, and vinegar produced the best weed control at the application rates used in this study.