Studies on the control of root knot nematodes (Meloidogyne species) on tomato in Tanzania using marigold plants (Tagetes species), ethylene dibromide and aldicarb

Abstract

Root knot nematodes (Meloidogyne spp) are a serious problem of vegetable production in Tanzania and feasible control methods are lacking. In this study, marigold plants (Tagetes minuta and T. erecta were compared to nematicides ethylene dibromide and aldicarb for control of root knot nematodes. Of the three, ethylene dibromide gave the most effective reduction of root galling and the poorest shoot growth and fruit yields, aldicarb gave the highest shoot growth and fruit yields and reduced the number of root galls by a factor of 21 in glasshouse conditions. Tagetes erecta and T. minuta reduced the number of galls by a factor of 4 and 6 respectively over the non‐treated controls. Similar results were observed in field conditions. There was a negative correlation between the reduction in number of root galls and the Increase in plant growth or fruit yields in treatments with aldicarb and marigold plants, but not in treatments with ethylene dibromide. This indicated phytotoxic effects of ethylene dibromide.

Keywords:

• tomato
• nematode
• marigold
• pesticide
• Tanzania

Notes

Department of Botany, University of Dar es Salaam, P.O. Box 35060, Dar es Salaam, Tanzania.