M. KARACHI

SADC-ICRAF Agroforestry Research Project, Tumbi Agricultural Research and Training Institute, Tabora, Tanzania

Abstract

Sixteen accessions of Sesbania sesban and 4 of S. macrantha were assessed for susceptibility to root-knot nematode (Meloidogyne javanica) under glasshouse and field conditions and the effect of Sesbania on the build-up of soil root-knot nematodes. In the field, Sesbania was planted on either ridges or flat land. All accessions were attacked by the nematode but at varied rates of infestation. Sesbanias planted on ridges were infected later than those on flat land; at the 3-month harvest, some accessions were still free of nematodes when grown on ridges. In general, accessions grown on ridges had lower galling and a smaller second-stage juvenile population in the roots than those on flat land. Overall, accessions 15036, 15024 and SR18B had the smallest numbers of second-stage juveniles on both ridges and flat land. All tomato test plants grown in soil from Sesbania plots were infected by the nematode but the level of infestation did not reflect that of Sesbania growing in the field. The data indicate that planting Sesbania would provide a medium for perennating the root-knot nematode.
The implications of the results are discussed in the context of planting Sesbania in smallholder crop production systems found in east and southern Africa.