Control Measures of Nematodes
Solar heat : Most nematodes are sensitive to desiccation and heat. Summer ploughing has been a traditional practice in Indian agriculture. Exposure of soil to sun and wind kills a large number of nematodes. Two ploughings at fornight's interval during summer months, after harvest of rabi crops, can reduce nematode population substantially.
Soil solarization: Involving the mulching of moist soil with clear polythene sheet for a few weeks in summer, the soil solarization is effective in reducing nematode populations, and controlling other soil borne pathogens and weeds. This practice conserves soil moisture and prevents wind erosion.
Organic amendments: Certain organic amendments like deoiled seed cakes of plants like neem, karanj, mahua, etc. when applied to soil are known to be highly effective in suppressing plant parasitic nematodes. The organic amendments also promote beneficial nematodes, especially, the microbivorous nematodes, which play an important role in the regulation of soil health.
Botanical nematicide: Certain substances of plant origin are known to be toxic to nematodes. A few commercial products based on neem seed kernel, Oil, leaves, etc., have become available. These can be applied to seed and nursery-beds for reducing nematode damage to plants at the early growth stage. Recent research work has shown that many other plants have nematicidal properties. Species of Calotropis, lpomea, etc., have been found to contain nematode suppressive moieties in their leaves.
Biological control of nematodes: A large number of antagonistic microfauna and microflora have been discovered. A few of these have shown potential as biological control agents. Several egg parasitic (Paecilomyces, Verticillium), toxin producing fungi (Catenaria, Harposporium, etc.) have been identified and exploited for the management of nematodes on a small scale. Similarly, different kinds of bacteria have been found useful in suppressing nematodes and reducing crop damage. The parasitic bacteria, Pasteuria penetrans; and toxin producing bacteria such as Pseudomonas fluorescens, etc., have been found to be highly effective biological control agents of nematodes. The biological control of nematodes can serve as an important tool in organic farming systems. These organisms can be introduced into the nematode infested area and ecological conditions can be created to enable their establishment in the problem area. Improving organic matter status of the soil through the use of FYM, crop residues, etc., provides the necessary substrate for rapid growth of the nematodes antagonistic organisms.
In case of a pest outbreak that cannot be handled by biological means, insecticides approved for organic farming can be used.
One of the biggest rewards of organic farming is healthy soil that is alive with beneficial organisms. This healthy soil has its natural "immune system" intact and thus can control several diseases. Several beneficial bacteria and fungi compete with, and/or prey upon, disease-causing organisms. These 'good' microorganisms function like the white blood cells in our bodies keeping the harmful bacteria and fungi that causes disease in check.