Bioherbicidal activity of Sinapis alba seed meal extracts

• Published in: Industrial crops and products 2018-05, Vol.115, p.174-181
• Main Authors: Morra, Matthew J., Popova, Inna E., Boydston, Rick A.
• Format: Article
• Language: English
• Subjects: active ingredients; Amaranthus powellii; bioassays; Bioherbicides; biopesticides; Glucosinolate; herbicidal properties; Mustard seed meal; nitriles; phenols; Phytotoxic plant extract; phytotoxicity; Setaria viridis; Sinapis alba; Thiocyanate; thiocyanates; weed control
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2018.02.027

[Display omitted] •Yellow mustard (Sinapis alba) seed contains compounds that are phytotoxic.•The compounds responsible for phytotoxicity have not been definitively identified.•Extracts obtained from S. alba seed meal are potentially viable bioherbicides.•The main active ingredient in the extract demonstrating phytotoxicity is SCN−.•S. alba extracts are viable bioherbicides especially for preemergence weed control. Although seed meal from yellow mustard (Sinapis alba L.) is a potential tool for controlling weeds as a consequence of produced phytotoxic products, use is limited by batch-to-batch variability and logistical constraints. Our objective was to develop an efficacious bioherbicide by extracting and identifying the active ingredients in S. alba seed meal that demonstrate phytotoxicity to greenhouse-grown Powell amaranth (Amaranthus powellii) and green foxtail (Setaria viridis). Companion bioassays with separate potential active ingredient solutions containing ionic thiocyanate (SCN−), 4-(hydroxymethyl)phenol (4-OH), or 2-(4-hydroxyphenyl)acetonitrile (Nitrile) at concentrations approximating those in the extract were performed. When applied pre- (PRE) or postemergence (POST), SCN− and extracts were the most active solutions on both weed species. The highest rate tested of SCN− of 2.8 kg ha−1 controlled Powell amaranth 98% and green foxtail 84% compared to the highest rate of extract (2.8 kg SCN− ha−1) that controlled Powell amaranth 97% and green foxtail 82%. POST application of the extract was less effective as compared to SCN− solutions, with SCN− showing 97% control of Powell amaranth and 71% control of green foxtail as compared to the extract displaying only 46% control of Powell amaranth and 23% control of green foxtail. Little or no herbicidal activity was observed on both weed species following PRE or POST application of 4-OH or Nitrile. Development of a bioherbicide based on extracting and concentrating SCN− from S. alba seed meal is feasible, especially if scale up activities focus on eliminating the need for alcoholic extractants and yield higher active ingredient products.