Sunflower extracts effects on seedling growth

At this paper allelopathic effect of sunflower on seedling growth was studuied. Physiological parameters of the selected weeds such as photosynthesis, lipid peroxidation, and sucrosesynthase activity were reduced by applying higher concentrations of sunflower extracts. Sunflower extracts negatively affected the shoot dry weight and seed ling height of the weeds. The highest concentration of malondialdehyde (MDA) in johnson grass and wild mustard were 0.065 and 0.069 innol g(-1) FW respectively when the highest concentration of extracts was used. The photosynthetic rate was 6.1 Jimol CO2 cm(-2) S-1 in the former and 2.1 mol CO2 cm(-2) S-1 in the later weed. The sunflower extracts inhibited the wild mustard and johnson grass seedling growth and increased lipid peroxidation causing cell wall damage. The results suggest that sunflower extracts can be considered as weed biological control agents due to their inhibitory and toxic effects on plant cellular structures, physiological mechanisms, and biochemical reactions. (C) 2015 IASE Publisher All rights reserved.