Aqueous leaf extracts of gum-yielding trees of agroforestry importance influence seed germination of winter season intercrops

Different plant species produces different allelo-chemicals and variable allelopathic effects; hence, it is imperative to assess the allelopathic effect of various tree species, being used in agroforestry systems on growth of understory crops. In present study, allelopathic effect of aqueous leaf extracts of important gum-yielding plant species, namely Acacia nilotica, Acacia senegal, Anogeissus pendula and Butea monosperma on four winter season crops of Bundelkhand region were assessed in separate bio-assay trials. Study consisted of two factors viz., concentrations of leaf extracts [four levels: 15%, 10%, 5% and control (0%)] and test crops (Brassica campestris, Cicer arietinum, Lens culinaris and Triticum aestivum). Higher concentration of the extracts showed more inhibitory effects on seed germination and growth of test crops, in all the trials. Per cent (%) reduction in seed germination in different crops due to application of the extracts over control was found minimum in T. aestivum (in A. nilotica and B. monosperma) and C. arietinum (in A. senegal and A. pendula), and maximum in B. campestris, in all the trials. Similar results were also noticed in terms of total dry weight (mg) 5 plants−1 in all test crops with selected gum-yielding plants. Thus, the results indicated that T. aestivum for A. nilotica and B. monosperma, and C. arietinum for A. senegal and A. pendula can be compatible intercrops; however, these are the results of bio-assay trials, hence field experiments need to be undertaken to evaluate the allelopathic effect of A. nilotica, A. senegal, A. pendula and B. monosperma.