Nematicidal Effect of Sunn Hemp Amendment on Infectivity and Reproductivity of Soil Nematodes in Vegetable Plants

The first step to control many noxious nematodes by using organic amendments, is to select the suitable biocidal plant such as, sunn hemp (SH) Crotalaria juncea L. this plant used mainly as a green manure and it is a poor host for several plant- parasitic nematodes as well. In the present study Sunn hemp was cultivated as an amendment plant in the crop rotation. The dried dropped leaves were plowed in the soil. After two weeks, the initial population (Pi) of nematodes was estimated, the land was divided into small plots and cultivated with one of following plants: Lactuca sativa L., Chorchorus olitarius , Cucumis sativus, Allium cepa, Lycopersicum esculentum, Capsicum annum, Solanum melongena, Phaseolus vulgaris, Vigna sinenses and Vicia faba. Final population (Pf) and rate of reproduction were estimated, and data showed that, lethal effects varied with regard to nematode type. Rotylenchulus reniformis was the high tolerant to SH as a green manure followed by Pratylenchus, while, Meloidogyne and Helicotylenchus were less tolerant to sunn hemp amendment. On the other hand, sunn hemp increased the abundances of non parasitic nematodes. In conclusion, using sunn hemp could increase the fertility of the soil, and promising as an alternative for managing plant parasitic nematodes efficiently and has the ability to enhance the free living nematodes.