The Chilli Root-knot Nematode, Meloidogyne incognita, belonging to the Family Heteroderidae of the Order Tylenchida, is a serious pest that causes significant yield losses and reduces the quality of crops worldwide. It is a microscopic, worm-like organism classified as a plant-parasitic nematode. The nematode damages chilli plants by invading the roots and forming galls or knots. In addition to causing direct damage to chilli plants, they can also facilitate the entry of secondary pathogens, leading to further damage and yield loss.
Control strategies include crop rotation, use of resistant varieties, soil solarization, and application of nematicides. To effectively manage this pest, it is important to understand its life cycle, its preferred habitats, and the best methods for controlling it. This article will provide an overview and discussion of the Chilli Root-knot Nematode Pest in Chilli crops, including its symptoms, identification techniques, and control.
Chilli Root-knot Nematode Pest Management
Life Cycle of Chilli Root-knot Nematode Pest in Chilli Crop
The life cycle of the Chilli Root-knot Nematode pest has four stages. They are egg, nymph, pupa, and adult. The life cycle of the Chilli Root-knot Nematode begins with the egg stage. The female nematode lays eggs in a gelatinous mass, often visible as small white balls on the surface of infected roots. Depending on environmental conditions, the eggs are deposited in the soil and hatch into second-stage juveniles (J2) after 10 to 14 days. The J2 is the infective stage of the chilli root-knot nematode.
The J2 is attracted to plant roots by chemical signals and actively seeks out suitable hosts. Once they locate a host, they penetrate the root tissues and migrate toward the vascular system. Once inside the root, the J2 undergoes several developmental stages, feeding on plant tissue and growing. They induce the formation of specialized feeding structures called giant cells, which provide them with a source of nutrients.
As the J2 feed and grow, they cause the formation of galls or knots on the roots, which interfere with the plant’s ability to take up nutrients and water. After approximately 2 to 3 weeks, the J2 molt into fourth-stage juveniles (J4), which continue to feed and develop within the root tissues. The J4 are stationary and do not move through the soil like the J2. They remain inside the roots until they reach maturity and are ready to reproduce.
After several weeks of development, the J4 molt into adult males or females. They continue to feed on plant tissue, produce eggs within their bodies, and start the lifecycle again. The entire lifecycle of the chilli root-knot nematode can be completed in as little as 20 days under optimal conditions, allowing for multiple generations to develop within a single growing season.
Occurrence of Chilli Root-knot Nematode Pest in Chilli Crop
- Location of Chilli Root-knot Nematode Pest: This pest infests Chilli crops in India, Bangladesh, Nepal, Africa, Sri Lanka, China, Thailand, Malaysia, Vietnam, Indonesia, the United States, Mexico, Brazil, Colombia, Ecuador, the Philippines, New Zealand, and Australia.
- Host Range: The Chilli Root-knot Nematode pest infects crops like Chilli, Tomato, Brinjal, Okra, Cotton, Soybean, Peanut, Banana, Citrus, and Snake gourd.
Factors Favoring the Population Increase of Chilli Root-knot Nematode Pest in Chilli Crop
- Temperature – The pest prefers warm temperatures between 20°C to 30°C. The nematodes become inactive or die below 14°C or above 35°C.
- High Soil Moisture – The pest requires high soil moisture for its su