Resumen
The present study was undertaken to observe the root-knot problems in Ajiwa dam area, Katsina state. Surveys were done to determine the level of infestation, incidence, intensity and frequency of root-knot disease and to identify the root-knot nematodes associated with vegetables. The study showed that root-knot disease incidence in the area was fairly very high. Of the fields visited, about 42% fields were infested. Incidence of the disease in different fields and on different vegetables showed wide variation. Short pepper and tomato were most affected crops followed by onion, lettuce and carrot. Spinach was less affected. Two species M. incognita and M. javanica of root-knot nematodes were identified. M. incognita showed highest frequency (71.4%) and was dominant species in the studied area. M. javanica has lowest frequency (28.5%).DOI: http://dx.doi.org/10.3126/ije.v4i1.12189International Journal of Environment Volume-4, Issue-1, Dec-Feb 2014/15, Page: 204-209