Effect of Soil Applied Herbicids on Weed Flora, Yield Attributes, Oil Content and Constituents in Sunflower (Helianthus annuus L.)

Field experiments showed that superior control of the existing weed flora was obtained by applying: alachlor + linuron, alachlor + chloramben and cyanazine. Herbicidal treatments of alachlor, trifluralin, prometryn and oxadiazon were highly effective in controlling dominant weed species. Some herbicidal treatments produced sunflowers with larger head diameter as compared to unweeded check. As a result of suppressed weed interference, alachlor in combination with linuron or chloramben and cyanazine accounted for the highest seed yield values in 1985 and 1986. Chemical analyses exhibited that sunflower oil content was not affected by weed control applications. Furthermore, oil constituents (oleic, linoleic, steric and palmitic fatty acids) expressed insignificant responses to applied treatments.