TABLE CONTENTS

The Effect of Organic Amendments for Nematode Control in Rural
Vegetable Gardens in South Africa
Tefu, G., M. Daneel, D. Mdluli, W Steyn & T. Poto
ARC-ITSC, Private Bag X11208, Nelspruit 1200, SA
A survey conducted in rural areas in the eastern and northern parts of South Africa revealed
serious problems with nematodes, especially Meloidogyne spp. Due to the high nematode
numbers, vegetable growing has become a problem and many gardens have been abandoned.
Although these people have no funds available for nematicides, other practices could help
reduce the problem and allow them to produce reasonable yields.
To determine the effect of organic amendments on yield and nematode numbers, two 2-year
trials were done with vegetables at Nelspruit Experimental Farm. The treatments included
cattle manure, chicken manure, compost, plastic filled with sterilized medium, permaculture,
an untreated control, fenamiphos, oilcakes of soy and sorghum, sorghum, Tagetes and plastic
cover (solarization).
After two years, results showed that permaculture delivered the best results for all the
vegetables, even with very high nematode infestations in the tomatoes and spinach. Although
nematodes are not affected directly, the effect on yield is huge. After two years and three
crops, yield was enhanced by 60 - 80% compared to the control. Permaculture is a technique
where a trench is dug and filled up with garden waste including green and brown material,
old papers, rotten fruit and vegetables and than covered with soil. The second best treatment
was chicken manure, followed by several other amendments. It is obvious that most of the
amendments had a positive effect on the crops and although the direct effect on nematodes
was insignificant, the benefit in terms of growth and yield were substantial.
5 th International Congress of Nematology, 2008 318