Herbicidal activity of glucosinolate-containing seedmeals

Abstract

Defatted seedmeals from 15 glucosinolate-containing plant species were analyzed for herbicidal activity by determining inhibition of seedling emergence when added to a sandy loam soil containing wheat and sicklepod seeds at concentrations of 0.1, 0.5, and 1% (w/w). In general, the seedmeals were more phytotoxic to wheat than sicklepod. For wheat, all of the seedmeals significantly inhibited seedling emergence at the 1.0% concentration. At the 0.1% concentration three of the seedmeals (Indian mustard, money plant, and field pennycress) completely inhibited wheat emergence. For sicklepod emergence, eight of the seedmeals were completely inhibitory at the 1% level (Indian mustard, field pennycress, garden rocket, Siberian wallflower, English wallflower, garden cress, sweet alyssum, and evening stock) and four were completely inhibitory at the 0.5% level (brown mustard, garden rocket, English wallflower, and sweet alyssum). Intact glucosinolates and their corresponding hydrolysis products varied among the seedmeals with the highest activity. Major hydrolysis products produced by the seedmeals with the most phytotoxicity, respectively, included 2-propenyl (allyl) isothiocyanate (AITC) by brown mustard seedmeal, allyl thiocyanate and AITC by field pennycress seedmeal, erucin (4-methylthiobutyl isothiocyanate) by arugula seedmeal, 3-butenyl isothiocyanate and lesquerellin (6-methylthiohexyl isothiocyanate) by sweet alyssum seedmeal, and isopropyl isothiocyanate by money plant seedmeal. From our data it appears that both the type and concentration of glucosinolates and their hydrolysis products present in the seedmeals affect seed-emergence inhibition.

Glucosinolates and biofumigation: fate of glucosinolates and their hydrolysis products in soil

“…In another study thiocyanate was also detected, but not in as high concentrations as isothiocyanate, but the thiocyanate was more persistent in the soil (Brown et al 1991). Thiocyanates are believed to be important for the weed suppressive activity of glucosinolate containing plants, and because they are not as easily degraded as isothiocyanates, their effect may persist (Vaughn et al 2006;Rice et al 2007). Thiocyanate is an anion and thus it is anticipated that it is weakly sorbed in soil, but it has been demonstrated that thiocyanate disappearance in soil is due to both to microbial degradation and sorption (Brown and Morra 1993).…”

Extraction, Composition and Functional Properties of Pennycress (Thlaspi arvense L.) Press Cake Protein

“…Vaughn and co-workers [26] found that in pennycress seed and press cake, the only glucosinate present is sinigrin (allylglucosinolate), a compound that is also present in other edible plants such as brown mustard and horseradish and imparts the characteristic pungent flavor to these spices. We reported previously that the sinigrin content was 100 times less in the seed meal protein isolate than in the starting sample [7].…”

Evaluating Mustard Seed Meal for Weed Suppression in Potato (Solanum tuberosum)

“…Beets (Beta vulgaris) and lettuce (Lactuca sativa) were injured when seeding into MSM amended soil (Rice et al, 2007). Wheat emergence was inhibited by seed meals from 15 glucosinolate-containing plant species when applied at 1% (w/w) to a sandy loam soil (Vaughn, Palmquist, Duval, & Berhow, 2006). Delaying planting of the crop following MSM application may reduce phytotoxicity of MSM to the crop, but would also limit the longevity of weed suppression in the crop.…”