Allelopathic and shading effects of Mangifera indica L. on germination and early growth performance of associated crops

Abstract

Mango ( Mangifera indica L.) is widely grown as an agroforestry tree in different parts of the world especially in Ethiopia. However, its dense canopy and expected allelopathic effect make it very difficult to survive for many of the associated crops grown under it. Therefore, current study was undertaken with the main objective to investigate the allelopathic and shading effects of mango on the germination and early growth performance of food crops and medicinal plants. Leaf extract of mango was tested to find out its inhibitory or stimulatory effect on maize, pea nut and haricot bean with varying concentration of extracts (0, 10, 15 and 20%) at lab and pot study. Results of the study witnessed the inhibitory effects of its extract on germination and early growth performance of cereal and pulse crops for most of the parameters studied. However, severity of inhibition was more pronounced with increase in concentration of the extract. Similarly, shading intensity of mango tree on two Hibiscus varieties WG-H Jamaica and WG-S were tested at a certain canopy distances (1/3rd, 1/2 and at tree periphery) from the bole of mango tree. Results reflect the increase in growth performance of both the varieties with increase in canopy distances from the bole of the tree probably due to better transmission of light. It is recommended that Hibiscus varieties should not be planted at the very closest distance from the mango trees stem due to allelopathic and shading effects, respectively.