Effect of bio-agents on number of galls/plant
Results (Table 1) revealed that all the treatments were effective in reducing the number of galls/plant over the check during both the years. At 30 days after transplanting, minimum (12.7 and 10.0 galls/plant) was recorded with
Bacillus subtilis @20 g/M
2 (2 x 10
8 cfu/g) followed by 13.7 and 10.7 galls/plant with carbofuran @1 kg a.i./ha. Average 15.0 and 12 galls/plant was recorded with soil application of
P.
florescence @ 20 g/ M
2 (2 x 10
8 cfu/g), whereas 21.5 and 27.5 galls/plant were in case of
Bacillus pumilus @20 g/ M
2 (2 x 10
8 cfu/g). In control, 35.1 and 52.7 galls /plant were recorded. In comparison of control, 63.6 and 73.6% reduction in galls per plant was recorded with
Bacillus subtilis @20 g/M
2 (2 x 10
8 cfu/g) followed by 60.7 and 71.7 % with carbofuran @1 kg a.i./ha. At 60 days after transplanting, 20.9 and 18.8 galls/plant were recorded with
Bacillus subtilis @20 g/ M
2 (2 x 10
8 cfu/g) followed by 22.6 and 24.2 galls/plant with carbofuran @1 kg a.i./ha. About, 52.7 and 62.5 galls/plant were recorded in control during both the years. In comparison of control, 60.2 and 69.8% reduction in galls formation was recorded with
Bacillus subtilis @20 g/M
2 (2 x 10
8 cfu/g). Previously,
Muthulakshmi et al., (2010) reported that
P.
fluorescens and
T.
viride were applied in soil alone or in combination effective to check root knot nematode disease and to improve growth of mulberry with increased leaf yield.
Saravanan et al., (2021) reported that application of single bioagent either
P.
fluorescens @ 10 gm/plant or
T.
viride @ 10 gm/plant along with neem cake were with highest plant growth parameters and poor nematode infestation in banana.
Effect of bio-agents on growth and yield
Data (Table 2) revealed that all the treatments were effective in increasing plant growth. At 30 day after transplanting, maximum (63.1 and 61.1 cm) plant height was recorded with
Bacillus subtilis @ 20 g/ M
2 (2 x 10
8 cfu/g) followed by 62.7 and 59.7 cm with
P.
florescence @ 20 g/ M
2 (2 x 10
8 cfu/g) during both the years, respectively. At 60 day after seedling transplanting, maximum (70.0, 75.2 cm) plant height was recorded with
Bacillus subtilis @20 g/ M
2 (2 x 10
8 cfu/g) followed by 69 and 73.56 cm with
P.
florescence @ 20 g/ M
2 (2 x 10
8 cfu/g) and 68.50 and 72.00 cm with
Bacillus pumilus @20 g/ M
2 (2 x 10
8 cfu/g) during both the years, respectively. Minimum (66.7 and 71.2 cm) plant height was recorded in control at 60 day after transplanting in both years, respectively. All treatments were also found effective in enhancing the grain yield over the check. Maximum grain yield (14.0, 13.3 q/ha) was recorded with
Bacillus subtilis @20 g/ M
2 (2 x 10
8 cfu/g). Previously many researchers have reported similar results.
Kumar (2018) reported that soil application (@2.5 kg/ha) of
Pseudomonas fluorescens inhibit the nematode population and increase the plant biomass.
Anitha and Rajendra (2005) reported that integration of
P.
fluorescens (2.5 kg/ha), neem cake (1 ton/ha) and carbofuran (1 kg a.i./ha) highly effective in improving plant growth and yield in the nursery as well as in main field.
Das et al., (2017) found that application of carbofuran @ 0.3 gm/ M2 in the nursery bed and field application of fungal bio-agent
Trichoderma viride @ 2.5 kg /ha after transplanting quite effective and economic for the nematode management with increased grain yield.
Effect of bio-agents on final nematode population
Data (Table 1) indicated that all the treatments were found effective in decreasing the nematode population in the field over the check. The initial nematode population 415 per 200 g of soil was recorded before the planting the crop in the field. After harvesting, minimum (620 and 686.6 J2 per 200 g of soil) was recorded with
Bacillus subtilis @20 g/ M
2 (2 x 10
8 cfu/g). Maximum (970 and 880 J2 per 200 g soil) were recorded in control during both the years, respectively.
Narasimhamurthy et al., (2017) found similar results against rice root knot nematode when applied different bio agents and carbofuran 3G @ 0.3% a.i. alone or in combination. They recorded all the treatments significantly superior over check with respect to growth parameters and nematode population.
