Abstract:
The management of root-knot nematodes (Meloidogyne spp.) has become a
challenging task in tomato (Solanum lycorpesicum) production, due to the
withdrawal of effective chemical nematicides. Currently, crude extracts of different
plant species are being researched as alternative to chemical nematicides, with
promising results. The objective of this study was to determine the effect of crude
extracts of wild garlic (Tulbaghia violacea) on the growth of tomato under
greenhouse conditions, and the suppression of M. incognita race 2 population
densities. Treatments consisted of four levels of crude extracts viz. 0, 2, 4 and 8 g
per pot, were arranged in a randomised complete block design with 10 replicates.
Seedlings were inoculated with 1000 juveniles of M. incognita race 2 at transplanting
and treated with crude extracts two days later. At 56 days, the crude extract of T.
violacea increased plant height, stem diameter, number of cluster, flowers, fruits and
leaves by 43-73%, 108-200%, 57-81%, 55-110%, 170-223% and 51-66%,
respectively. It also increased the root mass and shoot mass by 95% and 96%,
respectively. Crude extracts of T. violacea did not have any effect on soil pH and
electrical conductivity (EC). Crude extracts of T. violacea consistently reduced
population densities of M. incognita race 2 by 50, 64 and 73% in roots at 2, 4 and 8
g crude extracts, respectively and by 21, 30 and 58% in soil at similar levels,
respectively. In conclusion, crude extracts of T. violacea have the potential to
improve growth of tomato plants and suppress population densities of M. incognita
race 2 and could be used as botanical nematicide in tomato production.
