1Plant Protection Unit, Queensland Department of Primary Industries, 80 Meiers Road,
Indooroopilly, Queensland 4068
2 Resource Management Institute, Queensland Department of Primary Industries, 80 Meiers
Road, Indooroopilly, Queensland 4068
Introduction
Vetiver grass (Vetiveria zizanioides) is well known for its tolerance to adverse soil
conditions and is used as a contour hedge to prevent soil erosion on steep slopes in some
countries. Anecdotal evidence also indicates that when grown adjacent to orchard trees for
soil and water conservation purposes, Vetiver appears to improve tree growth.
In Queensland, Vetiver grass is being used to stabilize soil on slopes in sugarcane and
pineapple plantations. Since root-knot nematodes (Meloidogyne spp.) can be a problem on
both crops (Spaull & Cadet 1990, Caswell et all 1990), the status of Vetiver as a host
of root-knot nematode was of interest. This work aimed to answer that question.
Materials and Methods
Two Vetiver varieties were screened for resistance against five root-knot nematode
populations. The populations are representative of the main genetic groups of Meloidogyne
in Australia and consist of four species (viz. M. arenaria, M. incognita [populations B 1
and B2], M. javanica and M. hapla). They were identified using DNA technology (Hugall et
al 1994). The two Vetiver varieties used were Monto, a sterile selection, and a
non-sterile type from Western Australia. The test plants were grown in the glasshouse in
200 mm pots in a sterile sand mix. Once they were established, five replicate plants were
inoculated with 10,000 root-knot nematode eggs. A susceptible tomato cultivar (cv. Tiny
Tim) was used as a standard for comparative purposes. Plants were harvested 6 weeks after
inoculation, when egg masses on tomatoes were mature. Roots washed free of soil were
immersed in a 1% NaOCl solution for three minutes and eggs were collected on a 38�m sieve
and counted.
Results and Discussion
Both Vetiver varieties were highly resistant to all five root-knot nematode populations.
Reproduction was approximately 1000-fold less than on the susceptible tomato. Vetiver also
compared favorably with other grasses that have been found to be resistant to
root-knot nematode in similar tests. Our results confirmed those of de Moura et al
(1990) who found that Vetiver was "immune" to both M. incognita race 1 and M.
javanica.
Conclusion
Since the grass was resistant to all major species of Meloidogyne, Vetiver is unlikely to
exacerbate problems caused by root-knot nematodes when used as a cover, companion or
hedgerow crop.