Evaluation of fluazifop-P-butyl and napropamide usefulness for weed control in borage (Borago officinalis L.) cultivation

Fluazifop-P-butyl 187.5 g ∙ ha–1 applied after borage emergence was selective to cultivated plants and very efficient in farmyard grass and couch grass control in one year field experiment. Napropamide 900 g ∙ ha–1 and 1350 g ∙ ha–1 mixed with the top 3–5 cm soil layer immediately before seed sowing was slightly toxic to some borage seedlings but did not affect further plant growth. It controlled the annual grasses and some dicotyledonous weeds well during 10 weeks after seed sowing. Herbicides did not influence borage emergence, the plant fresh weight, the yield of fresh borage herb, the number of seeds sett on one plant, 1000 seeds weight and the seed oil content. The content of gamma-linolenic acid in the oil obtained from seeds set on plants growing on plots treated with napropamide 900 g ∙ ha–1 and the content of erucic acid in the oil obtained from seeds set on plants growing on plots treated with fluazifop-P-butyl 187.5 g ∙ ha–1 and on plots treated with napropamide 1350 g ∙ ha–1 were significantly lower.