Role of Organic Additives in the Sustainable Management of Phytoparasitic Nematodes

Abstract

Phytoparasitic nematodes are recognized as one of the important limiting factors for successful cultivation of crops. Compared to other pathogens, plant parasitic nematodes are sometimes difficult to control because they live in the soil and possess a great ability to attack almost every part of the plant. They can be effectively managed by application of chemical nematicides, but at the cost of environmental pollution, toxicity, as well as residual hazards and effect on food chain. Plant protectionists have been evaluating many nematode management strategies like soil solarization, use of fungal and bacterial biological control agents, trap as well as antagonistic crops, and GAP for management of plant parasitic nematodes in crops. Application of organic amendments therefore is a successful alternative strategy for managing plant parasitic nematodes in soil. A good number of organic amendments such as vermicompost, nematicidal plants, farm yard manure, protein-rich wastes, and animal and green manures have been effective in the management of plant parasitic nematodes infesting a wide range of agricultural crops. The use of organic amendments can reduce disease caused by nematodes directly by affecting soil properties and indirectly by improving plant growth, changing root physiology, and enhancing populations of antagonistic microorganisms and productivity. Several nematotoxic chemicals have been reported to be released during decomposition of the organic amendments in soil which are detrimental to nematodes. Also, various factors such as soil type, agronomic practices, rate of application of organic additives, etc. are greatly implicated in bringing down the population below economic threshold. Application of organic amendment improves the soil physicochemical properties, alters the C/N ratio, adds different micronutrients, and thereby improves the plant growth, which ultimately help the plant to withstand nematode attack. We have discussed different types of organic amendments that are used during the management process. We also give emphasis on how they can reduce the nematode population. Due to the chemical released during the process, the nematode population was found to be less harmful to the crop. It has been discussed how this organic matter is important to soil health and the environment of the soil rhizosphere through changes which make the nematodes to thrive less in the soil and how it increases the soil’s properties and the yield of the crops. Many reports indicated that the performance of organic amendments as bionematicides is not satisfactory. In the present chapter, an emphasis has been given to discuss the current understanding pertaining to application of organic additives in the management of phytoparasitic nematodes. Recent progress in plant nematology in terms of their management through organic approaches has been put forth.