Comparative effectiveness of carbofuran and aqueous extracts from the leaves of neem, rattle weed, bitter leaf and clove in root knot nematode control on false sesame, Ceratotheca sesamoides Endl

Abstract

False sesame (Ceratotheca sesamoides Endl) is an important indigenous vegetable which is collected mainly from the wild. Attempts at cultivating this vegetable have been faced with the problem of root knot nematode infection which needs to be controlled using cheap, safe and environmentally friendly methods. An experiment using potted plants was therefore carried out to compare the effects of 0, 50, 75 and 100% of water extracts of clove (Syzygium guineense Wild DC), bitter leaf (Vernonia amygdalina Del.), siam weed (Chlomolaena odorata L.R.M. King and Robinson), neem (Azadirachta indica A. Juss) with that of carbofuran (a synthetic nematicide) in the control of root knot nematode infection of false sesame. The results showed that root damage at 8 and 16 WAP (weeks after planting) and nematode population in the soil at 16 WAP were significantly lower (P<0.05) in all the treated plants than in the untreated control plants. Neem and siam weed treatments at both 8 and 16 WAP were effective as the carbofuran treatment in preventing root damage of false sesame. As a result of reduction in soil nematode population and root damage, treated plants were observed to be significantlytaller with more branches and leaves than the untreated control. Also, leaf area, shoot weight and weight of 100 seeds were significantly higher in the treated plants. The higher concentrations of treatments were more effective than the lower concentrations.

JARD Vol. 5 (2) 2006: pp. 191-202