Agronomic Comparisons of Herbicides with Different Active Ingredients and Mechanical Hoeing for Weed Control in Oleic and Linoleic Type Sunflower (Helianthus annuus L.) Hybrids

The objective of this study was to detennine the effects of five traditional herbicides containing different active ingredients compared with mechanical hoeing for weed control on seed yield components, seed oil content, and fatty acid composition in sunflower. According to the results, herbicides especially post-emergence applications under stress conditions can adversely affect agronomic yield and seed oil components in sunflower. Introduction Sunflower (Helianthus annuus) is one of the most important oilseeds with an annual 21.15 million metric tons of vegetable oil and 22.56 million tons of meal production in the world (USDA, 2021). Widespread distribution of pesticides is also known to cause problems with the apiculture and surface waters (Lari et al., 2014: Since bees are the most important pollinators of crops, the use of pesticides can considerably reduce the yield of cross-pollinated crops (Önemli, 2005a; Önemli, 2005b; Barganska et al., 2014; Jumarie et al., 2017). The aim of the present study was to investigate the effect of five herbicides including different active ingredients applicated with respect to labeled dose and time making comparisons with hoeing weed control on seed yield, some yield components, seed oil content, and oil fatty acid profiles of two oleic and two linoleic sunflower hybrids.