Pathogenicity and Control of the Root-Knot Nematode, Meloidogyne incognita on Fluted Pumpkin, Telfairia occidentalis

Abstract

Two consecutive seasons of screenhouse trials were conducted at the National Horticultural Research Institute (NIHORT) Ibadan to determine the pathogenicity of Meloidogyne incognita on five lines of fluted pumpkin (EN 2000 – 4, EN 2000-6, EN2000-10, EN2000-11, EN2000-13) and efficacy of 50 and 75% aqueous extracts from the leaves of Morinda lucida and Cassia acutifolia as compared with that of 2.5kg a.i/ha Carbofuran in the nematode control. Control experiment was also set up which was devoid of any treatment. Experimental design was a factorial type fitted into a complete randomized design. Results from the study revealed that development and vegetative growth of plants treated for nematode control were significantly better (P<0.05) than those of the untreated control. The untreated control plants had significantly shorter vine length, smaller vine
girth, fewer numbers of leaves and higher gall indices. The higher concentration (75%) of the extracts recorded significantly higher growth, vegetative yield and reduced root gall as compared with the lower concentrations of the extracts. Generally, carbofuran treatment gave significantly better result in all the measured parameters except in the mean vine length, where it was not significantly different from 75%. Morinda lucida leaf extract. The levels of treatment were directly proportional to plant growth and vegetative yield and inversely proportional to root gall index. The aqueous plant extract had no phytotoxic effect on the different Telfairia lines but rather improved their growth and vegetative performance. Significant differences were also observed among the Telfairia lines. EN2000-4 exhibited overall superiority over the other lines while EN2000-13 recorded significantly higher gall index than the other lines though it did not differ significantly from EN2000-6, EN2000-10 and EN2000-11 in terms of vine length, vine girth and number of leaves. EN2000-13 thus exhibited a higher level of susceptibility to the root knot
nematode, Meloidogyne incognita.

Keywords: Meloidogyne incognita, pathogenicity, control, plant extracts, carbofuran.