📙 Allelochemicals are present virtually in all plant tissues, including leaves, flowers, fruits, stems, roots, rhizomes, seeds and pollen. They inhibit the growth of some species at certain concentration or may stimulate the growth of same or different species at lower concentration. Multipurpose Tree species like Melia dubia and Leucaena leucocephala are grown under agroforestry system throughout India to meet the various demands of the people but its deleterious effect on the long run on agriculture crops and soil is unknown. Hence identification and quantification of physiochemical properties, allelochemicals and their effect on germination, seedling growth and dry matter production of agricultural crops forms the main thrust area of research.