Research Papers: Chemotherapy of Dioscorea alata for Disinfestation of Scutellonema bradys

Abstract

Steeping Scutellonema bradys infected yam seed pieces (Dioscorea alata) in 1,000 ppm aqueous solutions of nematicides, nitrogenous fertilizers or disinfectants for 30 minutes effectively controlled nematode infection and tuber damage. Shoot emergence from carbofuran, formalin and ammonium sulphate treated seed pieces was reduced 29, 29 and 14% respectively. Shoot emergence from D-D, oxamyl, calcium nitrate or calcium hypochlorite treated seed pieces was unimpaired. All mean weights of tubers produced from treated seed pieces were significantly greater (P=0.05) than the untreated controls after 6 months' growth in the greenhouse. Formalin, carbofuran and D-D treated seed pieces produced the greatest yields. Untreated seed pieces had a reduced tuber growth, a high incidence of dry rot and high nematode populations. The data show that chemotherapy of yam seed pieces with formalin, carbofuran, D-D or nitrogenous fertilizers are highly beneficial and technically practical.