**1. Introduction**

With ever increasing world population and its impact, there is a significant pressure to feed the world by agriculturists. Demand for growth of major agriculture commodities is imperative. One major component that militate against achieving this objective is the effort by pests and diseases to reduce yield of agriculture crop production. The impact of both biotic and abiotic stress on production has a greater effect on our aim of increasing agricultural productivity. Many management practices especially pesticides application to mitigate pests and diseases incidence have directly negative influence on the surrounding environment [1, 2].

Pesticides use is regarded as one of the major and common agricultural management practices with a growing evidence of negative impacts on the ecosystem for their application. Any form of synthetic pesticides used ends up creating environmental as well as health concerns. These products may find their way contaminating water bodies resulting in contamination to human and aquatic lives, residual in agricultural produce, causing metabolic disorders to humans when contaminated foods are consumed. They also pose high financial cost to farmers with serious financial burden on output due to their expensive nature.

Many natural resources conservatives have called for reduction in the application of these pesticides and resort to natural, environmentally friendlier and healthy alternatives/practices that require reduction, if not complete their elimination [3, 4]. Many

biological, chemical and physical factors also influence soil quality, among these are the microbial communities in the rhizosphere that contribute to soil quality thereby enhancing plant growth and health [5, 6]. The extent of microbial interaction among members have great significance. Among these microorganisms are the Plant Growth Promoting Rhizobacteria (PGPR) and the Arbuscular Mycorrhizae (AM). The later lives symbiotically with the plant in the rhizosphere due to its extensively hyphal network development thereby protecting the crop from pathogen attack [7], decreases biotic and abiotic stress and reducing disease incidence [6, 8]. Therefore, if the potentials of AM are properly harnessed in agriculture, it should be able to reduce sustainably the cost and use of synthetic pesticides in agriculture systems. This is because many soils contain the indigenous AM fungi that colonize the root systems [9], even though not all plants are dependent on Mycorrhizae, most increase yield when AM fungi are applied [10]. This is sure way to attain agricultural sustainability with the reduction in the pesticides and at the same time protecting the crops from pathogen attack and ensuring high yield. Therefore, this chapter tries to detail the role Mycorrhizae fungi play not only in protecting the plant as a biocontrol agents/bioprotectants of soil-borne pathogens but also promoting plant growth thereby realizing its full potential and ensuring maximum yield.
