Inter relationships of infectivity between the burrowing and root knot nematodes in black pepper, piper nigrum L Sheela M. S., Venkitesan T. S.* Department of Entomology, College of Agriculture, Kerala Agricultural University, Vellayani - 695 522. * Present Address: College of Horticulture, Kerala Agricultural University, Vellanikkara-680 654, Trichur, Kerala. Presented at Nematology Symposium held at Coimbatore, India in February, 1981 Abstract In Kerala serious damage to black pepper crop is caused due to infestation by the burrowing nematode, Radopholus similis and the root-knot nematode, Meloidogyne incognita. These species have been observed to infest the vines jointly as well as separately. A pot culture experiment was conducted to study the relative infectivity of these nematodes under the above situations. One thousand nematodes/1.51L. of soil as initial inoculum separately, jointly or in succession was tested under six treatments. The treatments involving nematodes either in combinations or othewise suppressed the growth of vines. Simultaneous inoculation of both nematodes suppressed plant growth to the maximum extent. Inoculation of R. similis and M. incognita in succession led to the reduction in leaf area, internode length, top and root development. The population build up of the nematodes was found to be accelerated when the two species were inoculated separately and there was decline in the population under combined inoculations. The root gall development was suppressed in plants inoculated with M. incognita and R. similis in succession. Top |