abstract in order to identify biodiversity of  plant parasitic nematodes in alfalfa and no comprehensive research about the plant parasitic nematodes associated with alfalfa,during 2002-2003, 33 soil samples were collected from alfalfa fields of several locations in alfalfa fields in ahar region, partly biodiversity plant parasitic nematodes in this crop were identified.nematodes extracted by c...

Published by the College of Tropical Agriculture and Human Resources (CTAHR) and issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Andrew G. Hashimoto, Director/Dean, Cooperative Extension Service/CTAHR, University of Hawai‘i at Mänoa, Honolulu, Hawai‘i 96822. An equal opportunity/affirmative action inst...

Restrictions on the use of conventional nematicides have increased the need for new methods of managing plant-parasitic nematodes. Consequently, nematode-antagonistic microbes, and active compounds produced by such organisms, are being explored as potential additions to management practices. Programs in this area at the USDA Agricultural Research Service investigate applied biocontrol agents, n...

Previous research has shown that population densities of plant-parasitic nematodes are reduced when a legume crop is grown in rotation with sugarcane. However, this effect is only temporary, as nematodes usually return to high densities within 12 months of planting sugarcane. This rapid resurgence suggests that natural enemies that normally keep plant-parasitic nematodes under control in natura...

Background: Plant-parasitic nematodes are important pests of horticultural crops causing damage and significant reduction in the crop yield of pineapple. A survey was conducted to determine the types, frequency and population distribution of plant-parasitic nematodes associated with pineapple in some pineapple-producing states in Nigeria. A total of 30 farms were sampled from Delta, Imo, and Cr...

Chemical composition, origin, and biological role of the surface coat (SC) of plant-parasitic nematodes are described and compared with those of animal-parasitic and free-living nematodes. The SC of the plant-parasitic nematodes is 5-30 nm thick and is characterized by a net negative charge. It consists, at least in part, of glycoproteins and proteins with various molecular weights, depending u...

Plant-parasitic nematodes can affect seedling production in forest nurseries when host seedlings are developmentally vulnerable, nematode populations are high, or opportunistic pathogens are present. Soil fumigation has been important for plant-parasitic nematode control in forest nurseries. Regulatory changes and rising costs of fumigant application are expected to affect nursery pest manageme...

Plant parasitic nematodes cause severe damage and yield loss in major crops all over the world. Available control strategies include use of insecticides/nematicides but these have proved detrimental to the environment, while other strategies like crop rotation and resistant cultivars have serious limitations. This scenario provides an opportunity for the utilization of technological advances li...

Bioengineering strategies are being developed that will provide specific and durable resistance against plant-parasitic nematodes in crops. The strategies come under three categories: (i) transfer of natural resistance genes from plants that have them to plants that do not, to mobilize the defense mechanisms in susceptible crops; (ii) interference with the biochemical signals that nematodes exc...

The sensitivity of acetylcholinesterases (ACHE) isolated from the plant-parasitic nematodes Meloidogyne arenaria, M. incognita, and Heterodera glycines and the free-living nematode Caenorhabditis elegans to carbamate and organophosphate nematicides was examined. The AChE from plant-parasitic nematode species were more sensitive to carbamate inhibitors than was AChE from C. elegans, but response...