Abstract
Numerous species of soil bacteria which flourish in the rhizosphere of plants or around plant tissues stimulate plant growth and reduce nematode population by antagonistic behavior. These bacteria are collectively known as PGPR (plant growth promoting rhizobacteria). The effects of six isolates of PGPR
Pseudomonas putida
,
Pseudomonas fluorescens
,
Serratia marcescens
,
Bacillus amyloliquefaciens
,
Bacillus subtilis
and
Bacillus cereus
, were studied on tomato plant growth and root knot nematode reproduction after 45 days from nematode infection. The highest number of shoot dry weight/g (43.00 g) was detected in the plant treated with
S. marcescens
; then
P. putida
(34.33 g),
B. amyloliquefaciens
(31.66 g),
P. fluorescens
(30.0 g),
B. subtilis
(29.0 g),
B. cereus
(27.0 g) and nematode alone (untreated) 20 g/plant. While the highest number of plant height was observed when plant was treated with
S. marcescens
,
P. fluorescens
,
P. putida
,
B. amyloliquefaciens
and
P. putida
52.66, 50.66, 48 and 48 cm respectively. No significant differences were seen between previous treatments but only had significant differences compared with untreated plant. The highest number of fruit/plant was observed when plants were treated with
S. marcescens
(10.66), then
B. amyloliquefaciens
(8.66),
P. putida
(8),
P. fluorescens
(8) and
B. cereus
(7.66). No significant differences between the last 4 treatments, but all had significant differences compared with untreated plants. The highest weight of plant yield (g) was observed with
S. marcescens
(319.6 g/plant) and the lowest weight of plant yield was observed in plants treated with nematode alone (untreated). On the other hand, the lowest numbers of J
2
/10 g of soil (78), galls/root, (24.33) galls/root, egg masses/root (12.66) and egg/egg masses were observed in the plants treated with
S. marcescens
.