Evaluation of various methods of weed control for increasing rhubarb yields

Four herbicides, monthly handweeding and a 15 cm deep straw mulch were evaluated for weed control during 1982 to 1987 on rhubarb (Rheum rhabarbarum L. ≡ R. rhaponticum L. ‘Victoria Red’). The straw-mulched plots produced larger plants, provided higher yields and had fewer weeds than all other treatments during the five years of these field trials. Yields in 1987 were 29·42, 17·65 and 13·06 tonnes/hectare for straw, handweeded and herbicide treatments, respectively. Monthly handweeding produced large plants and high yields, but required much more hand labour than mulching, making straw mulch the most cost-effective treatment. The four herbicides evaluated (glyphosate, fluazifop, sethoxydim and propyzamide) provided weed control for up to 1 month and would require reapplication during the growing season.