Eight antagonists; Bacillus subtilis, Bacillus thuringiensis, Trichoderma
harzianum, Gliocladium vimes, Paecilornyces lilacinus and three yeast
(Saccharomyces spp.) isolated from Egyptian soil at different concentrations were
used to control root-knot nematode. Meloidogyne javanica under laboratory and green
house conditions on tomato plants.
The most effective isolate in controlling root-knot nematodes was the isolate of
T. harzianum whereas the least effective were the isolates of yeast (Saccharomyces
spp.) under both laboratory , greenhouse and field conditions.
Under laboratory conditions applying the antagonistic bacteria, fungi and yeast
achieved high percentage of juvenile mortality at the highest concentration (1:10)
during all exposure periods especially after 72 hours.
Under greenhouse conditions T. harzianum was more effective in reducing
numbers of galls, egg-masses and eggs per plant and number 01'2“" stage juveniles in
soil whereas, the least effective isolates were those of the yeast (Saccharomyces
spp.). Adding all antagonistic bacteria, fungi and yeast increased the fresh weight of
root and shoot system on tomato plants at all tested concentrations especially in the
highest concentration (1 :10).
Using the antagonistic bacteria, fungi and yeast in both (filtrates and cells)
achieved high percentage of juvenile mortality during all exposure periods especially
after 72 hours under laboratory conditions. The most effective isolate filtrate on
juvenile mortality was T. harzianum, while the lowest effective was the isolate filtrate
of Saccharomyces spp. The most highest effective isolate cell on juvenile mortality
was Saccharornyces cerevisiae while the lowest effective was the isolate cell of T.
harzianum. The tested Saccharomyces spp. cells were more harmful to the nematode
juveniles than their filtrates of the same Saccitaromyces spp. Also, adding all
bioagents treatments decreased number of nematodes in both roots and sell. In
addition the crop of tomato increased after adding the treatments at concentration
(1 :10) under field conditions.