Effect of inoculum density of root knot nematode (Meloidogyne incognita) on okra (Abelmoschus esculentus L.)

Abstract

A pot culture experiment was conducted to find out the effect of different inoculum\rlevels of nematode on the plant growth and nematode multiplication on okra plant.\rFindings revealed that significant reduction occurred in plant growth parameters viz.,\rshoot length, root length, fresh shoot and root weight, dry shoot and root weight of\rplant inoculated with 1000 juveniles and above per pot. The highest gall index and egg\rmasses were also recorded at inoculums levels of 1000 and 10000, respectively. Nematode\rpopulation in soil increased progressively with an increase in nematode inoculum level\rfrom 10 to 10000 J2/ kg of soil. Maximum population was recorded at inoculum level of\r10000 J2/ kg of soil followed by 1000 J2/ kg of soil which were statistically at par. The\rreductions in growth parameters and nematode infestations were found to be directly\rproportional to the inoculums level. Considering the spectacular decline in plant growth\rparameters and steep rise in number of galls and eggmasses in infected roots caused\rby Meloidogyne incognita at the inoculum level of 1000 J2 /kg soil and above, so it is\rconsidered that 1000 J2 M. incognita /kg soil happened to be damaging the thresh hold\rin okra.