ABSTRACT
The vesicular-arbuscular mycorrhizal (VAM) symbioses are widespread throughout the vegetable kingdom. The application of pesticides will affect the antagonistic interaction between VAM and plant pathogenic organisms and their subsequent beneficial effect on plant development and growth. This chapter reviews the different effects of pesticides and plant pathogens on VAM symbiosis. Because VAM fungi and root pathogens commonly occur together in the roots and rhizosphere of the same plant, the potential role of mycorrhizae as biocontrol agents has recently received considerable attention. The mechanisms proposed to explain VAM fungal effects on soil-borne plant pathogens have generally been based on morphological and physiological changes induced in the plant by the VAM fungus. Because VAM fungi and root pathogens commonly occur together in the roots and rhizosphere of the same plant, pesticide application affects both organisms. The use of nematicides and fungicides which eliminate pathogens without affecting VAM fungi will help to increase plant growth.
