Abstract

Phenolics are low molecular compounds ubiquitous in all tissues of higher plants with great significance in plant development. Our understanding of some phenolic compounds in the last few decades has greatly improved. However, their biological, ecological and agronomical significance in the rhizosphere of most symbiotic legumes is much less clear. Further understanding of these biomole-cules will increase our knowledge of their contribution in soil and water conservation, weed manage-ment, mineral element nutrition, their impact as signal molecule in certain symbiotic relationships, and their role as defence molecules against soil pests and pathogens. This article reviews the bio-ecological and agronomical significance of phenolic compounds in the rhizosphere of a few studied symbiotic legumes and other plants.

Key words: Allelopathy, defence, flavonoids, growth inhibitors, soil structure, nutrients availability, pesticide, signal molecules, soil borne diseases, soil insects.