Nematodes: An Overview -Causes, Damages, Control and Prevention-

 

What are Nematodes?

Nematodes are the most common multicellular organisms on the earth. A handful of soil can contain thousands of microscopic worms, many of which are parasites of insects, plants, or animals. Despite the abundance of free-living species, such as nematodes that feed on bacteria, fungi, and other nematodes, the vast majority of species discovered have yet to be identified scientifically. Over 20,000 species have been identified in the phylum Nemata. Nematodes are simple creatures in terms of structure.  Adult nematodes have around 1,000 somatic cells and hundreds of cells that participate in the reproductive cycle. In nematodes, the alimentary canal, which extends from the mouth to the anus at the tail, has been characterized as a tube inside a tube. Nematodes do not have a separate circulatory or respiratory system while having digestive, neurological, excretory, and reproductive systems. They come in sizes ranging from 0.3 mm to over 8 meters.

Damages they Causes

They cost farmers millions of dollars in crop losses each year, but they may also cause issues in the city by destroying turfgrasses, trees and shrubs, and household plants. According to some estimates, there are over a million different species of nematodes, making them the second most populous organism behind insects. However, because most nematodes are very small, even microscopic, and colorless, few people are aware of or have seen them. They live in hidden dirt, beneath the water, or in the parasitized plants or animals, and only a handful have obvious direct impacts on people.

Signs and Symptoms

Common root symptoms of nematode infection include root knots or galls, root lesions, excessive root branching, injured root tips, and stunted root systems. A progressive decrease of the entire plant, wilting even with appropriate soil moisture, leaf yellowing, and fewer leaves are all symptoms of root infection on above-ground plant components. These are the symptoms of a plant that doesn’t have a properly functioning root system. Stem swelling and internode shortening are caused by the bulb and stem nematodes. Bud and leaf nematodes distort and kill bud and leaf tissue.

Control and Prevention

There are various techniques for controlling plant-parasitic nematodes. There are three sorts of control strategies: biological control, cultural control, and chemical control. The use of nematode-resistant plants is the most feasible way of biological control. Plant breeders use this control approach to cross natural nematode resistance genes into developed plant species to increase nematode resistance. The advantage of this approach is that it is a low-cost solution for producers to address their nematode issues. Only nematode-free nursery stock should be used for planting. In most nations, nursery inspectors would reject and destroy any nursery stock that exhibits symptoms of nematode infestation. Nematode-resistant cover crops should be used. Cover crops can help enhance soil structure and fertility, minimize soil erosion, offer animal feed, and keep weeds at bay. Importing soil (or plants with dirt on their roots) from regions where a hazardous nematode species is new to the area should be avoided.   Nematodes   Phylum: Nematoda  Common Name: Roundworms, Eelworms, Hookworm, Nematodes Appearance: Nematodes are one of the most diverse sets of organisms, practically found everywhere. They can be as small as 0.8mm to as large as 8m in length. They have a worm-shaped body covered by an external cuticle. The sharp needle-like mouthpiece allows them to puncture a hole in plants and animals to derive their nutrition. Host Plants or Food: Nematodes occur as plant or animal parasites, feeding on their body fluids to gain nutrition. They feed on other nematodes, insects, plant roots, and seeds. Territory: Throughout the world Mode of Damage:  Depending on the species, they may be sapsuckers or flower and seed feeders. The parasitic activity usually decreases the plant’s efficiency. Habits and Life History: Nematodes are one of the largest and most diverse sets of organisms. They are found around the globe in all conditions. From mountains to deserts and oceans, they are present everywhere. The sexes are usually separate; however, they may sometimes occur as hermaphrodites containing both male and female reproductive systems. After mating, the female lays eggs which are passed in the open through feces. The larva hatches out of the eggs and goes through 3 metamorphoses outside and 1 metamorphosis inside the host body to transform into an adult. It is the third larval stage that is infective and is ingested by animals or attacks the plant body.