Screening of five elite sweet potato cultivars against reniform nematode (Rotylenchulus mniformis) in the green house.

Abstract

Five elite sweet potato cultivars/lines were screened in the greenhouse for resistance against Reniform Nematode (Rotilenchulus reniformis) through artificial inoculation. The cultivars showed varying degrees of above and underground symptoms of nematode infection. The longest vine length of 122.28 cm was observed in RAB36 and the shortest in L676 being 72.85 cm. The RAB36 had significantly lowest number of nematode per gram of soil compared to other cultivars and B11 had the highest. The RAB36 had the highest mean tuber weight of 112.3 g compared to other cultivars and the lowest being 56.2 g in case of B11. The dry weight of the cultivars closely followed the pattern in fresh weight. Ninety per cent nematode mortality was observed in case of RAB36 compared to B11 with only 10 % in phenolic test. The mortality percentage in RAB32, DOY2 and L676 were 85, 50 and 25 respectively. The highest tuber crack of 10% was observed on 811 and only six per cent on L676. No tuber cracking was observed on the cultivars.