Physiological Response Of Two Sunflower Cultivars And Associated Weeds To SomeHerbicides

摘要

Two pot experiments were carried out during two successive summer seasons 2011 and 2012 at greenhouse of National Research Centre, Egypt to study the physiological effect of three different herbicides, Granstar (Tribenuron-methyl), Amex (Butralin) and Fusilade (Fluazifop-butyl) on the growth and yield of two sunflower cultivars (Giza 5 and Sakha 53) as well as their herbicidal effect on the growth of two associated weeds (Portulaca oleracea and Echinochliea colonum). The results indicated that Tribenuron-methyl was phytotoxic to P. oleracea and Fluazifop-butyl was phytotoxic to E. colonum without crop injury, while Butralin revealed phytotoxicity on both P. oleracea and E. colonum and was injurious to the crop. Tribenuron-methyl and Fluazifop-butyl showed high significant increase in the growth and yield of two sunflower cultivars. The chemical analysis indicated an increase in chlorophyll biosynthesis in sunflower leaves due to these two herbicides as well as increases in oil contents and some nutrient contents (macro-and micronutrients). The analysis of fatty acids composition indicated differences in the ratio of oleic and linoleic acids of two sunflower cultivars by Tribenuron-methyl, Fluazifop-butyl and Butralin.