ARS | Publication request: Onion and weed response to mustard (Sinapis alba) seed meal

Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 1, 2009
Publication Date: February 8, 2009
Repository URL: http://www.wssa.net/Meetings/WSSAAbstracts/abstractsearch.php
Citation: Boydston, R. A. 2010. Onion and weed response to mustard (Sinapis alba) seed meal. Combined meeting of the Society for Range Management and Weed Science Society of America, Denver, CO. 2010. Paper # PA-40.

Technical Abstract: Onion and weed response to mustard seed meal (MSM) were tested in greenhouse and field trials in 2007-2009. MSM was applied to the soil surface at rates of 1.1, 2.2, and 4.4 MT/ha. In greenhouse trials, onions were severely injured and stands reduced with all rates of MSM applied prior to onion emergence and at the loop stage. Injury to onions was less when MSM was applied at the 1-leaf stage compared to earlier applications, but onion stands were still reduced up to 46% at the 1.1 MT/ha. MSM at 2.2 and 4.4 MT/ha applied at the 1-leaf stage significantly injured onions and reduced stands 69% or more. In greenhouse trials, pigweed (Amaranthus retroflexus) stand counts were reduced 96% or more at 4 weeks after application of MSM applied at 1.1 MT/ha preemergence, at cotyledon stage, and 1-leaf stage. MSM at 4.4 MT/ha reduced pigweed stand 99% or more regardless of growth stage at application. In field trials, MSM band-applied to onions at the 2-leaf stage only slightly injured onions at 2.2 and 4.4 MT/ha rates. Three sequential applications of MSM at 1.1 and 2.2 MT/ha at three week intervals starting at the 2-leaf stage of onion reduced weed emergence in the treated band for three weeks following each application. Onion yield was not affected by MSM applications.