Effect of boron and yeast extract foliar application on growth, pod setting and both green pod and seed yield of broad bean (Vicia faba L.)

Abstract

A field experiment with broad bean (Vicia faba L) cv Super Aquadulse was conducted to study the effect of separate and combined foliar applications of boron (0, 25 and 50 ppm) and yeast extract (0, 2.5 and 5 ml/L) on growth, yield and some biochemical constituents. Results revealed that foliar application with boron and yeast extract either individually or in mixture significantly stimulated many growth aspects as number of leaves per plant, dry weights of both stems and leaves per plant, total leaf area and absolute growth rate as compared with the control treatment. In addition, foliar spraying with boron at 50 ppm and yeast extract at 5 ml/L increased photosynthetic pigments, N, P, K, B, total sugars, total free amino acids and crude protein values in leaves at 70 and 85 days after sowing. Moreover, boron and yeast extract treatments not only increased auxins and cytokinins but also decreased abscisic acid at 75 days after sowing during second season. All treatments not only increased number of formed flowers, setted pods per plant, green pod and dry seed yields, as well as satisfactory effect upon shedding percentage, i.e. reduced it. Hence, it could be recommended that foliar spraying with boron at 50 ppm and (or) yeast extract at 5 ml/L can be used to increase the final green pod and seed yield as well as seed quality of broad bean plants.