Effects of post-emergence herbicides on grain yield and yield quality of linseed (Linum usitatissimum L.)

Abstract The field experiments for this study were conducted during 2010 and 2011 at the research farm of the Agricultural College of Isfahan University of Technology in Iran. The study examined the physiological impact of nine post-emergence herbicides on linseed. Treatment with bentazon (1440 g a.i. ha –1 ) and bromoxynil (337.5 g a.i. ha –1 ) plus non-ionic surfactant significantly improved grain, protein, and oil yields compared to other herbicide treatments, though these did not differ significantly from the weed-free control. Higher grain protein percentages were observed with bromoxynil (450 g a.i. ha –1 ) and bromoxynil + MCPA (300 + 300 g a.i. ha –1 ). In contrast, dichlorprop-P + mecoprop-P + MCPA (620 + 260 + 320 g a.i. ha –1 ), bromoxynil (450 g a.i. ha –1 ), and 2,4-D caused severe phytotoxicity and yield reduction. Overall, bentazon and bromoxynil + non-ionic surfactant consistently enhanced both oil and protein yields, suggesting that these herbicides are the most effective options for commercial linseed production.