Developing Disease-Suppressive Soil Through Agronomic Management

Abstract

Plant diseases need to be controlled for maintaining the quality and quantity of food, feed, and fiber. Soilborne plant pathogens are one of the major limiting factors in most of the agroecosystems for the production of economical yields. Mostly they survive in bulk soil, but the parasitic relationship with crop plants is established in the rhizosphere. Soilborne pathogens caused numerous diseases like seed decay, pre-and postemergence damping off, wilting of roots, root rot, stem rot, crown rot, collar rot, decay of collar and fruits in trees, etc., and made serious losses to agricultural crops. These pathogens produce resting bodies in the soil which are long lasting and difficult to eliminate. The various diseases and symptoms are manifested by the plants which are difficult to diagnose and generally confused with the nondistinct symptoms caused by abiotic factors and/or due to lack of nutrients. Various approaches have been used to prevent, mitigate, or control the plant diseases. The practices for managing plant disease are largely based on genetic resistance in the host plants, management of the plant and its environment, and use of synthetic chemicals (Strange 1993). However, the use of agrochemicals needs to be ensured for safety of human health and environment (NRC 1996).