Potato Journal

Diagnostic surveys conducted at six localities in Himachal Pradesh indicated that root-knot, stunt and spiral nematodes were common in potato rhizosphere. Tuber infestation by root-knot nematode was observed only at Simla and Bhakulty. Among stunt nematodes, Quinisulcius capitatus was most predominant in all the samples and their populations ranged from 50 to 1430 per 100 ml of sample in 80 to 90 days old pototo crop.

The glass house studies indicated that this nematode could build-up 6 to 8 times in 45 days at inoculum levels of 10 to 1000 per plant in variety Kufri Jyoti. The pathogenic effects of nematode build-up even at an initial level of 100 was evident at 90 days by the decrease of fresh weights (45 to 48%) of shoot and root system. Initial levels of 100 to 10,000 nematodes per plant reduced 29 to 34 per cent tuber weights compared to uninoculated plants.