THE POTENTIAL OF VA MYCORRHIZAE FOR PLANT NUTRITION IN THE TROPICS

The improvement of the food situation in the tropics will depend on reliable production methods adapted to the various conditions within the tropical belt. Besides appropiate technologies for crop management practices, the conservation of soil-biological resources deserve special attention aiming at sustainable soil productivity. The present review demonstrates the importance of soil-microorganisms such as VA mycorrhizal fungi which substantially improve the exploitation of phosporus in soil for plant nutrition, thus enabling a more economic use of costly P fertilizers specially under the precarious soil conditions in the tropics. The authors appraise the crucial role of VA mycorrhizae under various stress conditions in relation to present knowledge and further research needs, with primary emphasis on two distinct tropical environments: the humid and arid/semiarid tropics.