Abstract

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The current study was conducted in a greenhouse belongs to the College of Agriculture / University of Al-Qadisiya during the growing season of 2013 in order to study the effect of spraying seaweed extract at concentrations of 0, 3 or 6 ml . L^-1 and amino acids at 0,400 or 800 mg . L^-1 in addition to their combination on some vegetative and anatomical characters of two cultivars of sweet pepper plant (Capsicum annuum L.) cv. Flavio F1 and California wonder. The results showed a significant increase in plant height, number branches and the percentage of dry matter of shoots in both cultivars when treated with seaweed extract at 6 ml. L^-1 or amino acids at 800 mg. L^-1. Also, it was clear from the anatomical characters of the stem that the thickness of cortex and vascular cylinder and diameter of vascular units increased significantly when they treated with the higher concentration of each of seaweed and amino acids as well, while the two factors caused a decrease in the thickness of the pith area in comparison with control treatment of both cultivars. For the interaction, the combination of seaweed extract at 6 ml. L^-1 and amino acids at 800 mg. L^-1 has recorded the highest values for most of the characters measured in comparison with control, except the pith thickness which was decreased as the concentration increased.

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