Influence of root-knot nematode, Meloidogyne incognita (Kofoid & White) Chitwood infection on different plant growth parameters in Mungbean, Vigna radiata (L.) Wilczek

Root-knot nematode, Meloidogvne incognita (Kofoid & White) Chitwood, is a major threat to mungbean cultivation. The pest causes a significant reduction in plant growth parameters that ultimately results in loss of grain yield. The present study was carried out under glass house condition to study the effect of different inoculum load of root-knot nematode M. incognita on plant growth, nodulation and nematode development and nutrients status of Mungbean. The results revealed a progressive decline in plant growth parameters viz., fresh and dry shoot weight and shoot length with respect to increase in inoculum level. However, fresh and dry root weight showed the opposite trend. The fresh and dry shoot weight was decreased by 44% and 66%, respectively at 4 J(2)s/g soil. The chlorophyll content in the leaves also decreased with the increase of inoculum level from 100-6000 J2s/pot. Nutrients contents of the plant viz. N, P, K, Ca and Mg were significantly reduced in shoots while in roots these was increased with an increase of inoculum levels. Nodulation was affected by 80% at the highest inoculum level i.e. 6000 J2s/pot. Also leghaemoglobin, bacteroid content and nitrogenase activity was reduced progressively with increased levels of nematode inoculum. Thus, the root-knot nematode, M. incognita interferes with the process of symbiotic nitrogen fixation between mungbean host and rhizobium and that can affect the quality of produce.