Effect of Some Growth Regulators on Yield and the Chemical Composition of Vicia faba (Part II)

Abstract

Summary 1. This experiment was carried out to study the effects of seed treatment with different growth regulators namely B-indole acetic acid, α-naphthalene acetic acid and gibberellic acid with various concentrations for different periods of soaking. Both number and weight of pods and seed were recorded as well as chemical composition of the seeds. 2. Both number and weight of pods did not show measurable changes due to IAA or NAA treatments. Similarly, GA did not affect the weight of pods, though their number was subjected to variation according to the period of soaking. 3. Treatment with IAA, for 24-hours, resulted in significant increase in the weight of seeds; though the 48-hour treatment showed a decreasing effect. Soaking in NAA, however, showed the reversible effect. Treatment with GA, though did not affect the weight of seeds, yet an increase in their number was attained with the 24-hour soaking period. 4. Total nitrogen content of seeds did not show significant changes due to IAA and NAA treatments. However, the lower concentration of NAA tends to increase the nitrogen content of seeds, the increase was mainly in the protein fraction. With GA significant decrease in nitrogen content was noticed with the higher concentrations of this hormone. 5. Analysis of bean seeds showed the complete absence of reducing sugars. The sucrose content was increased as a result of GA treatment, though IAA and NAA had no effect in this respect. It had been shown that IAA, NAA and GA resulted in highly significant increase in polysaccharide content of seeds.