Effect of Dalbergia sissoo extracts, rhizobium and nitrogen on germination, growth and yield of Vigna radiata

In bioassays, allelopathic activity of leaf and root aqueous extracts of Da lbergia sissoo Roxb. was studied on germination, growth, yield, nodulation and biochemical changes in Vigna radiata. In second study, effect of rhizob ium and nitrogen along with extracts was studied Chemical analysis of D. si ssoo leaves and root revealed the presence of appreciable amount of phenoli cs and carbohydrates and traces of flavonoids and terpenoids. Leaf and root extracts stimulated the germination, shoot length, production of seeds, se ed protein, leaf protein, soluble sugar of leaf, nodulation and adversely a ffected total chlorophyll of leaf and had no impact on nitrate reductase ac tivity (NR). Nitrogen along with all extracts adversely affected the germin ation, production of seeds, seed protein, chlorophyll and nodulation. It al so adversely affected the NR activity. Rhizobium treatments were better than extracts alone or nitrogen However, a ll treatments produced more number of seeds per plant with less weight. It is presumed that stimulatory activity may be due to the presence of phenols , carbohydrates, terpenoids and flavonoids in extracts.