The effects of herbicides on yield and quality components of sunflower (Helianthus annuus L.)

The aim of the present study was to determine the effect of herbicide applications including different active ingredients on seed yields, yield components, seed oil content and fatty acid composition, and to investigate herbicide residue of harvested seeds in sunflower. In this research, field experiments were conducted on farmer fields in Karamusul village of Lüleburgaz, Kırklareli during two sunflower growing period in 2014 and 2015. Used traditional herbicides were "Bonaflan® WG" with benfluralin, "Stomp® Extra" with pendimethalin, "Challenge 600" with aclonifen, "Targa Super" with quizalofop-p-ethyl and "Intervix® Pro" with imazamox active ingredients. Herbicides were applied at recommended dose by their manufacturer. Two Clearfield (LG5542CL and Colombi) and two non-Clearfield (P64LL05 and P64H34) sunflower hybrid cultivars were used as seed material. "Colombi" and "P64H34" have high oleic fatty acid composition while "LG5542CL" and "P64LL05" are high linoleic type sunflower cultivars. "Intervix® Pro" traditional herbicide with imazamox active ingredient decreased plant heights of two Clearfield hybrids (LG5542CL and Colombi) about 10% in both years. "Stomp® Extra" herbicide with pendimenthalin active ingredient applied pre-emergence decreased the number of days to flowering as resulting early flowering of linoleic sunflower hybrid "P64LL05" and oleic sunflower hybrid "P64H34" in 2014 and 2015. "Bonaflan® WG" with benfluralin application in "P64H34" cultivar had the highest seed yield in 2015. "Intervix® Pro" had insignificant negative effects on seed oil content and oleic acid ratio of Clearfield sunflower hybrid "LG5542CL" in 2014. Herbicide residue in harvested seeds of all applications was not detected according to limits (LOQ - Limit of Quantification). Key words: Fatty acid composition, herbicide application, herbicide residue, sunflower, seed yield, seed oil content, oil fatty acid composition