Meloidogyne graminicola has a well-established negative impact on rice yield in transplanted and ... more Meloidogyne graminicola has a well-established negative impact on rice yield in transplanted and direct-seeded rice, resulting in yield losses of up to 20 to 90 percent. Studies were undertaken to isolate potential native strains of bio-control agents to manage the devastating Rice Root Knot Nematode (M. graminicola). Eighteen bacterial strains and eleven fungal strains were isolated from the rhizosphere of crops like rice, okra, ash gourd, chili, beans and cucumber, enveloping diverse soil types from the Upper Brahmaputra Valley region of Assam. Six bacterial strains were gram-positive according to morphological results, while twelve others stained negatively. Fifteen bacteria were rod-shaped, two were coccus and one was diplococcus, and all the bacterial isolates showed signs of movement. All the bacterial strains exhibited positivity for gelatin hydrolysis and catalase test. Seven bacteria showed positive, while eleven showed negative reactions to possess the ability to deduce ca...
Ditylenchus myceliophagus underwent three moults outside the egg to become adult. Sex differentia... more Ditylenchus myceliophagus underwent three moults outside the egg to become adult. Sex differentiation could be made after the second moult with the position of germinal nucleus in the genital primordium. After third moult, sex could be easily differentiated by the germinal nucleus being located anteriorly in the genital primordium in female and posteriorly in male. D. myceliophagus took 28 days from hatching to become adult at 18±1°C.
A field study was conducted to collect indigenous technical knowledge followed by farmers for the... more A field study was conducted to collect indigenous technical knowledge followed by farmers for the management of rice pests at three villages of Lakhimpur district of Assam. Summer ploughing, use of healthy seed, burning of stubbles, application of different plant parts like Citrus grandis. Eupatorium odoratum, Polygonum sp. Vitex negundo. Azadiracta indica etc., water management practices, application of cow dung and goat excreta, use of dead crab/frog, use of bonefire were most commonly practised by the farmers for the management of various pests of rice. These practices are economical and environmental friendly.
Fifteen endophytic bacteria were isolated from leaves and stems of Solanum lycopersicum and Solan... more Fifteen endophytic bacteria were isolated from leaves and stems of Solanum lycopersicum and Solanum pimpinellifolium collected from different locations of the Jorhat district of Assam and characterized by morphological, cultural, biochemical and molecular approaches. An in vitro study was carried out to evaluate their potentiality as biological control agents against second stage juvenile of the root-knot nematode, Meloidogyne incognita race2. Thirty second stage juveniles (J2) of M. incognita race 2 were exposed to cell free culture filtrates of all the 15 bacterial endophytes in a sterile cavity block at a concentration of S(100%), S/2(50%), S/4(25%), S/6(17%) and S/10(10%) for a duration of 6, 12, 24, and 48 hr. The results revealed that all the isolates had the potentiality to significantly increase the mortality of the second stage juveniles (J2). The percent mortality was directly proportional to the duration of exposure time and the concentration of the culture filtrate. The ...
International Journal of Current Microbiology and Applied Sciences
Pot experiment was conducted to evaluate the efficacy of two formulations (talc formulation and v... more Pot experiment was conducted to evaluate the efficacy of two formulations (talc formulation and vermi formulation) of four bacterial nematode biocontrol agents viz., Bacillus subtilis, Bacillus pumilus, Bacillus megaterium and Pseudomonus flourescens as seed treatment against root knot nematode, Meloidogyne incognita on tomato. All the bioagents were tries at 10 and 20g / kg of seed. The experiment was terminated at 60 days after sowing the seed. The results revealed that all the treatments significantly increased the plant growth parameters and reduced the nematode multiplication over untreated control. However, maximum plant growth parameters and minimum galls per root system, eggmasses per root system, eggs per egg masses and final nematode population was recorded when seeds of tomato (var. Pusa Ruby) was treated with talc formulation of Pseudomonus flourescens @20g/kg followed by seed treatment with vermi formulation of Bacillus subtilis @ 20g/kg of seed.
Meloidogyne graminicola has a well-established negative impact on rice yield in transplanted and ... more Meloidogyne graminicola has a well-established negative impact on rice yield in transplanted and direct-seeded rice, resulting in yield losses of up to 20 to 90 percent. Studies were undertaken to isolate potential native strains of bio-control agents to manage the devastating Rice Root Knot Nematode (M. graminicola). Eighteen bacterial strains and eleven fungal strains were isolated from the rhizosphere of crops like rice, okra, ash gourd, chili, beans and cucumber, enveloping diverse soil types from the Upper Brahmaputra Valley region of Assam. Six bacterial strains were gram-positive according to morphological results, while twelve others stained negatively. Fifteen bacteria were rod-shaped, two were coccus and one was diplococcus, and all the bacterial isolates showed signs of movement. All the bacterial strains exhibited positivity for gelatin hydrolysis and catalase test. Seven bacteria showed positive, while eleven showed negative reactions to possess the ability to deduce ca...
Ditylenchus myceliophagus underwent three moults outside the egg to become adult. Sex differentia... more Ditylenchus myceliophagus underwent three moults outside the egg to become adult. Sex differentiation could be made after the second moult with the position of germinal nucleus in the genital primordium. After third moult, sex could be easily differentiated by the germinal nucleus being located anteriorly in the genital primordium in female and posteriorly in male. D. myceliophagus took 28 days from hatching to become adult at 18±1°C.
A field study was conducted to collect indigenous technical knowledge followed by farmers for the... more A field study was conducted to collect indigenous technical knowledge followed by farmers for the management of rice pests at three villages of Lakhimpur district of Assam. Summer ploughing, use of healthy seed, burning of stubbles, application of different plant parts like Citrus grandis. Eupatorium odoratum, Polygonum sp. Vitex negundo. Azadiracta indica etc., water management practices, application of cow dung and goat excreta, use of dead crab/frog, use of bonefire were most commonly practised by the farmers for the management of various pests of rice. These practices are economical and environmental friendly.
Fifteen endophytic bacteria were isolated from leaves and stems of Solanum lycopersicum and Solan... more Fifteen endophytic bacteria were isolated from leaves and stems of Solanum lycopersicum and Solanum pimpinellifolium collected from different locations of the Jorhat district of Assam and characterized by morphological, cultural, biochemical and molecular approaches. An in vitro study was carried out to evaluate their potentiality as biological control agents against second stage juvenile of the root-knot nematode, Meloidogyne incognita race2. Thirty second stage juveniles (J2) of M. incognita race 2 were exposed to cell free culture filtrates of all the 15 bacterial endophytes in a sterile cavity block at a concentration of S(100%), S/2(50%), S/4(25%), S/6(17%) and S/10(10%) for a duration of 6, 12, 24, and 48 hr. The results revealed that all the isolates had the potentiality to significantly increase the mortality of the second stage juveniles (J2). The percent mortality was directly proportional to the duration of exposure time and the concentration of the culture filtrate. The ...
International Journal of Current Microbiology and Applied Sciences
Pot experiment was conducted to evaluate the efficacy of two formulations (talc formulation and v... more Pot experiment was conducted to evaluate the efficacy of two formulations (talc formulation and vermi formulation) of four bacterial nematode biocontrol agents viz., Bacillus subtilis, Bacillus pumilus, Bacillus megaterium and Pseudomonus flourescens as seed treatment against root knot nematode, Meloidogyne incognita on tomato. All the bioagents were tries at 10 and 20g / kg of seed. The experiment was terminated at 60 days after sowing the seed. The results revealed that all the treatments significantly increased the plant growth parameters and reduced the nematode multiplication over untreated control. However, maximum plant growth parameters and minimum galls per root system, eggmasses per root system, eggs per egg masses and final nematode population was recorded when seeds of tomato (var. Pusa Ruby) was treated with talc formulation of Pseudomonus flourescens @20g/kg followed by seed treatment with vermi formulation of Bacillus subtilis @ 20g/kg of seed.
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