Influence of growth stimulants with rhizobium inoculation on the yield of mung bean (Vigna radiata L.)

Rhizobium has unique ability to form nodules in legumes,served marvellously in the agricultural systems. plant hormones like auxins,gibberellins,cytokinins etc. influenced the growth of plants or parts of plants. although plants synthesize auxins endogenously yet exogenous application has more assenting effects on plants. exogenous application of auxins can affect the endogenous level under sub-optimal conditions. studies were planned to assess impact of exogenously applied indole acetic acid (iaa) and l-tryptophan (l-trp) with and without rhizobium inoculation on the yield of mung bean at soil bacteriology section,faisalabad. fertilizer dose i.e. 30-60 kg np ha-1 was applied while iaa and l-trp @ 10-5 m following two application methods i.e. seed soaking and foliar spray followed by completely randomized design (crd). rhizobium was isolated from mung bean and screened out for auxin biosynthesis potential and for other biochemical tests. results (mean of two years) revealed that rhizobium inoculation significantly improved the yield components of mung bean with and without exogenous application of iaa and l-trp. iaa and l-trp applied either by seed soaking or foliar spray with rhizobium inoculation proved better than their respective controls. rhizobium inoculation produced significantly higher pod and straw yield i.e. 29.65,43.37 with l-trp and 28.95,43.55 g pot-1 with iaa,respectively. rhizobium inoculation produced higher nodules 69,nodule mass 0.458 g pot-1 with l-trp and 63 and 0.462 g pot-1 with iaa,respectively. higher grain and plant n was observed with seed soaked l-trp with rhizobium i.e. 3.72 and 1.203 % while with iaa i.e. 3.70 and 1.183%. similarly,higher grain and plant p was observed with seed soaked l-trp with rhizobium inoculation. rhizobiuminoculation improved the soil n and available p with l-trp and iaa. auxin (iaa) and its precursor l-trp affected the mung bean growth parameters and effect was more pronounced with rhizobium inoculation and seed soaking proved better option than foliar spray. © 2017,university of agriculture. all rights reserved.