STUDIES ON THE ALLELOPATHIC EFFECTS OF SOME AGROFORESTRY TREE CROPS

Abstract
The allelopathic influence of Eucalyptus tereticornis, Casuarina equisetifolia and Leuceana leucocephala was tested by growing crops of sorghum, cowpea and sunflower on topsoil and rhizosphere soil from plantations of those trees or on field soil either mulched with dry leaves or irrigated with aqueous leaf extracts. Crop germination, root length and dry matter production were depressed. Maximum reductions were obtained with top soil and by the effect of eucalyptus. Sorghum proved most susceptible to these influences.