Rate of Root Knot Disease Complex on Two Crops Eryngium foetidium and Calocacia gigantica of Manipur

Abstract

Eryngium foetidium and Calocacia gigantica are indigenous crops of Manipur. The two crops was heavily infected by root knote nematode M. incognita. An experiment was conducted at the PG Department of Zoology, DM College of Science from March 2019 up to November 2019. Plants with inoculums levels of 1000 and 10000 juveniles showed not only reduction in plant growth but stunting, yellowing of leaves and wilting appearance. The control plants i.e. uninoculated were free from root knot galls. An increase in the level of nematode inoculums from 10 to 10000 juveniles resulted in a significant increase in host infestation as indicated by number of root knot galls. Maximum root knot galls were recorded at the inoculation level of 10000 2nd stage juveniles/pot which was least at the level of 10 2nd stage juveniles/pot. The rate of multiplication was found inversely proportional to the population density. The host infestation rate and nematode multliplication pattern of root knot nematode on Eryngium foetidium and Calocasia gigantica was studied using different inoculum viz. 0, 10, 100, 1000 and 10,000. The economic damage of threshold level was 100 nematode which caused 31.54% reduction on the fresh root weight formed over control. Maximum disease incidence and retardation in plant growth was found in 1000 and 10,000 nematode per plant.