Submitted to: Western Society of Weed Science Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 1, 2008
Publication Date: July 21, 2008
Citation: Boydston, R.A. 2008. Mustard Seed Meal suppresses Weeds in Potato and Peppermint. Western Society of Weed Science Meeting Proceedings.61:37. Technical Abstract: Seed meal is a co-product remaining after pressing mustard seed to remove the oil. Seed meals containing high glucosinolates have been reported to have herbicidal activity. Weed suppression with seed meal of Sinapis alba, variety Ida Gold was evaluated in field trials on potatoes and peppermint in 2006 and 2007. In potato, mustard seed meal at 0.5 ton/acre applied to the soil surface reduced the number of early season weeds compared to the nontreated check in 1 of 2 years and 1 and 2 ton/acre rates significantly reduced early season weed counts both years. Final weed dry weight was similar among all treatments except the 2 ton/acre mustard meal, which was 13% and 32% of the nontreated checks in 2006 and 2007, respectively. Dried distillers grains applied at 1 ton/acre increased early season hairy nightshade counts and total weed counts in 2006, but slightly reduced hairy nightshade and total weed counts in 2007. Potato tuber yield or specific gravity were not statistically significantly different among treatments, but nontreated checks and plots treated with dried distillers grains, which lacked weed suppression, averaged the lowest yields in 2006. Mustard seed meal applied to the soil surface at 1 to 2 ton/acre reduced the number of broadleaf and grass weeds 2 WAT in newly planted peppermint in 2006 and 2007. By 4 WAT, the weed density in plots treated with 0.5 and 1 ton/acre mustard meal was similar to the nontreated checks, but weeds were smaller in the plots treated with mustard meal. Some initial phytotoxicity was evident on peppermint treated with white mustard seed meal at 2 ton/a in 2006, but it was short-lived and peppermint grew normally thereafter. Field pennycress (Thlaspi arvense) seed meal applied at 0.5, 1, and 2 ton/acre did not reduce total weed emergence at 2 WAT and tended to increase the number of grass weeds in 1 of 2 years.