Abstract
M.Sc. (Zoology)
Paratrichodorus meyeri De Waele & Killian, 1992 is extremely sensitive to surface
sterilization; therefore in vitro culture could not be utilized for the mass culture of this
nematode and another method had to be developed. Hermetically sealed glass containers were employed successfully for the reproduction of Paratrichodorus meyeri. With this method an average 12 times increase was achieved on tomatoes over a period of 60 days. Certain crops were evaluated in the greenhouse to establish their status as hosts for Paratrichodorus meyeri. The aim of this experiment was to determine which plants could be used as hosts for the reproduction of the nematodes in the greenhouse. It was found that tomatoes (cultivar Roma VF) and wheat (cultivar Gamtoos) were excellent hosts, tobacco (cultivar K51E) and onions (cultivar Bon accord) good hosts, tobacco (cultivar TL 38) and lettuce (cultivar Great Lakes) average hosts and sweetcorn (cultivar Golden Bantam), beetroot (cultivar Formanova) and cabbage (cultivar Sugar Loaf) unsatisfactory hosts for this nematode species.
The aim was also to determine the effect of this nematode species on tobacco and
cotton. Various inoculation levels of Paratrichodorus meyeri were tested on tobacco
cultivars K51E, TL33 and RK and the cotton cultivar Acala 1517170. It was established
that an inoculation level as low as 50 - 100ft! Qsoil had a negative effect on cotton
(cult. Acala 1517170). A damage threshold value of 100ft! Q soil on the tobacco
. cultivar K51E was established. It is also possible for tobacco cultivar RK to support this nematode species without any adverse effects it can even be beneficial for this
particular cultlvar. It was also determined that a negative correlation exits between the
initial number of nematodes inoculated and the final population.