Krishnashis Das - Academia.edu (original) (raw)

Papers by Krishnashis Das

Scientific Reports, Apr 20, 2023

Mono-cropping of maize-wheat, mechanical disintegration of soils, and continuous chemical fertili... more Mono-cropping of maize-wheat, mechanical disintegration of soils, and continuous chemical fertilization have deteriorated soil health in the Indo-Gangetic Plains. We studied the long-term impact of pulse-based cropping systems with integrated nutrient management on soil physical and chemical properties and yield sustainability. We evaluated four different cropping systems: (1) maize-wheat (M-W), (2) maize-wheat-mungbean (M-W-Mb), (3) maize-wheat-maize-chickpea (M-W-M-C), (4) pigeonpea-wheat (P-W) each with three degrees of soil fertilization techniques: (1) unfertilized control (CT), (2) inorganic fertilization (RDF), and (3) integrated nutrient management (INM). The field experiment was undertaken in a split-plot design with three replications each year with a fixed layout. P-W and M-W-Mb systems enhanced soil properties such as volume expansion by 9-25% and porosity by 7-9% (p < 0.05) more than M-W, respectively. P-W and M-W-Mb increased soil organic carbon by 25-42% and 12-50% over M-W (RDF). P-W system enhanced water holding capacity and gravimetric moisture content by 10 and 11% (p < 0.05) than M-W. Pulse-based systems (P-W and M-W-Mb) had higher available nitrogen (8-11%), phosphorus (42-73%), and potassium (8-12%) over M-W (p < 0.05). M-W-Mb increased 26% maize yield and 21% wheat yield over M-W (p < 0.05) at the thirteenth crop cycle. P-W system had a higher sustainable yield index (p < 0.05) of wheat over the M-W. Thus, pulse inclusion in the cropping system in combination with INM can enhance physical and chemical properties vis-à-vis sustainable yield index over the cereal-cereal system. Soil physical properties are a significant part of the soil system working and empower to assess the ecosystem sustainability 1, 2. The physical properties of soil as bulk density, soil structure, and water-holding capacity are signs of good soil well-being in the long-run 3. The water-holding capacity of soil is regulated by: (1) pore size distribution, (2) surface area of soil, and (3) aggregate stability. Fundamentally, soil aggregates (macro-and micro-aggregates) minimize organic matter mineralization, sequestering soil organic carbon (SOC) and nutrients 4. Theoretically, increased water-holding capacity, soil moisture content, and aggregate stability are indicators of the positive impact of crop diversification and balanced fertilization on soil health 1, 5. Soil aggregated nutrients strongly influenced by crop management practices that include tillage/mechanical disruption, crop rotation, and fertilization techniques 6. Rice-wheat (9.64 m ha area) and maize-wheat (1.83 m ha area) are the two dominant cropping systems in the Indo-Gangetic plains (IGP) 6, 7. These cropping systems reduced crop productivity and soil ecology because of SOC depletion, macro-and micro-nutrient deficiency, the decline in soil microbial/ biological properties, and groundwater table depletion 8, 9. Pulse crops in the cropping system might reduce soil health deterioration and increase yield sustainability 9. A long-term study indicated that the chickpea yield was more sustainable than the maize 10. Therefore, it is necessary to evaluate the long-term impact of pulses in cropping systems on soil physical and chemical properties and crop yields in the IGP.

Soil and Tillage Research, 2019

We evaluated the long-term impact of zero tillage (ZT) in post-rainy seasons (winter and summer) ... more We evaluated the long-term impact of zero tillage (ZT) in post-rainy seasons (winter and summer) crop/s, crop residue management, and crop diversification on soil aggregation and carbon sequestration. The field experiment (started in 2009) was undertaken in split-plot design for seven consecutive years on a sandy loam soil of Kanpur, India. The experiment comprised of four tillage and crop residue management treatments: PTRconventional tillage (CT) without crop residue (PTR-CT), PTR-ZT without crop residue (PTR-ZT-R), PTR-CT with crop residue incorporation (PTR-CT+R), and PTR-ZT with surface crop residue retention (PTR-ZT + R) in main plot, and three cropping systems: rice-wheat (RW), rice-chickpea (RC), and rice-chickpea-mungbean (RCMb) in subplot. Treatment PTR-ZT + R resulted in 13% (p < 0.05) higher water stable macroaggregate over the PTR-CT. Meantime, PTR-ZT+R increased carbon content in macro-aggregate (28%) and meso-aggregate (39%) over the PTR-CT, because of added carbon through the surface-laden crop residue. The tillage and crop residue management followed the sequence of PTR-ZT+R > PTR-ZT-R > PTR-CT+R > PTR-CT (p < 0.05) across the soil depths for active and passive carbon pools. After seven years, PTR-ZT+R enhanced soil microbial biomass carbon (SMBC) and particulate organic carbon (POC) by 70 and 56% over PTR-CT, respectively. The RCMb and RC rotations increased (p < 0.05) the macro-and meso-aggregates, and aggregate mean weight diameter compared to the RW rotation in both soil depths. Crop rotations had the following trend: RCMb > RC > RW (p < 0.05) for SMBC and POC. Notably, treatment PTR-ZT+R with RCMb or RC rotations largely increased the carbon management index compared to the PTR-CT and RW systems. The structural indices and soil carbon parameters were significantly correlated to the rice grain yield, except microaggregated carbon. Thus, crop diversification with grain legume/s, zero tillage in post rainy season crop/s, and crop residue retention provided not only higher soil aggregation but also increased carbon sequestration in Inceptisol of subtropical humid climate.

Plant Response Mechanisms to Abiotic Stresses [Working Title]

Reduction in biomass and pollen fertility are the two major constraints resulting in poor grain y... more Reduction in biomass and pollen fertility are the two major constraints resulting in poor grain yield in major pulses grown under rainfed agrosystem. Generally, pulses are encountered into both heat and drought stresses during terminal reproductive stages. Though pulses have many adaptive features to counter the adverse effects of various abiotic stresses but yield is substantially reduced when the magnitude of these stresses is very high. The factors have been identified to enhance grain yield under stress environments which include promotion of biomass in the above ground part enabling crops to reserve a maximum amount of photosynthesis and water in the plant system itself before the onset of drought and heat stresses during reproductive stages. Various physiological mechanisms and fertility enhancement components including genetic diversity in key traits have been discussed here to improve yield of pulses under stressed conditions.

Asian Journal of Dairy and Food Research, 2022

Background: Mungbean is consumed as whole, sprouts or dehusked splits, in form of dal. Dal is pre... more Background: Mungbean is consumed as whole, sprouts or dehusked splits, in form of dal. Dal is prepared after removal of outer husk cover and splitting the cotyledons in abrasive emery roller mills to improve esculent properties. In the process of husk removal, milling byproduct, mixture of husk and cotyledon powder, is generated, which is usually utilized as low value cattle feed. The milling byproduct contains bioactive compounds useful for human health. In the study biochemical properties of two mungbean cultivars, namely, Shikha and Virat, were evaluated for whole, dal milling byproduct and its fractions, to explore using milling byproduct of mungbean for potential edible usages. Methods: In this study, mungbean cultivars were milled in abrasive roller after water soaking pre-milling treatment. Milling byproduct was fractionated into three particle sizes, i) greater than 1.0 mm, ii) greater than 0.125 mm and iii) less than 0.125 mm. Biochemical components, viz, protein, phenols, ...

Beneficial Microbes in Agro-Ecology, 2020

Cyanobacteria, also known as blue green algae, are the prokaryotic group of organism which consti... more Cyanobacteria, also known as blue green algae, are the prokaryotic group of organism which constitutes a major part of phytoplankton and a primary colonizer in different habitats. The practical importance of cyanobacteria as a source of nitrogen fertilizer in rice is well recognized (Singh and Singh, 1989) and plays a significant role in sustaining and improving rice field productivity (Rodger et al., 1979; Pabbi, 2008). Earlier it was believed that higher yield was due to nitrogen fixation only. But a number of studies showed that improved yield is not only due to nitrogen fixation but also due to production of growth promoting substances (Venkataraman and Neelakantan, 1967; Marsalek et al., 1992), phosphate solubilising ability (Bisoyi and Singh, 1988), addition of organic matter (Singh and Bisoyi, 1989; Das et al., 1991), pesticide tolerance (Ahmed and Venkataraman, 1973; Kaushik and Venkataraman, 1983, Pabbi International Journal of Current Microbiology and Applied Sciences ISSN...

The world has been confronted with an energy crisis, depletion of fossil fuel and increasing conc... more The world has been confronted with an energy crisis, depletion of fossil fuel and increasing concern of global climate change; therefore, there is a need to find an alternative biological solution which is green and free from pollution. Microalgae are highly diverse, single or multicellular, microscopic photosynthetic organisms and utilize sunlight and carbon dioxide for synthesis of food. Microalgal biomass has been considered to be an important and valuable resource due to appreciable growth rate and high levels of lipids, carbohydrates and other value-added products. Microalgae have been utilized for biofuel production such as biodiesel, bioethanol, biohydrogen and biomethane production over the years. Conservation of genetic resources is an important aspect for every nation. Various conservation techniques are available to conserve the microorganisms. This chapter is mainly focused on conservation of microalgae and application aspect of microalgae in the area of biofuel production.

Indian Journal of Microbiology, 2016

Biofilmed biofertilizers have emerged as a new improved inoculant technology to provide efficient... more Biofilmed biofertilizers have emerged as a new improved inoculant technology to provide efficient nutrient and pest management and sustain soil fertility. In this investigation, development of a Trichoderma viride-Mesorhizobium ciceri biofilmed inoculant was undertaken, which we hypothesized, would possess more effective biological nitrogen fixing ability and plant growth promoting properties. As a novel attempt, we selected Mesorhizobium ciceri spp. with good antifungal attributes with the assumption that such inoculants could also serve as biocontrol agents. These biofilms exhibited significant enhancement in several plant growth promoting attributes, including 13-21 % increase in seed germination, production of ammonia, IAA and more than onefold to twofold enhancement in phosphate solubilisation, when compared to their individual partners. Enhancement of 10-11 % in antifungal activity against Fusarium oxysporum f. sp. ciceri was also recorded, over the respective M. ciceri counterparts. The effect of biofilms and the M. ciceri cultures individual on growth parameters of chickpea under pathogen challenged soil illustrated that the biofilms performed at par with the M. ciceri strains for most plant biometrical and disease related attributes. Elicitation of defense related enzymes like L-phenylalanine ammonia lyase, peroxidase and polyphenol oxidase was higher in M. ciceri/biofilm treated plants as compared to uninoculated plants under pathogen challenged soil. Further work on the signalling mechanisms among the partners and their tripartite interactions with host plant is envisaged in future studies.

Folia microbiologica, Jan 12, 2017

Rhizobia are a group of organisms that are well known for their ability to colonize root surfaces... more Rhizobia are a group of organisms that are well known for their ability to colonize root surfaces and form symbiotic associations with legume plants. They not only play a major role in biological nitrogen fixation but also improve plant growth and reduce disease incidence in various crops. Rhizobia are known to control the growth of many soilborne plant pathogenic fungi belonging to different genera like Fusarium, Rhizoctonia, Sclerotium, and Macrophomina. Antagonistic activity of rhizobia is mainly attributed to production of antibiotics, hydrocyanic acid (HCN), mycolytic enzymes, and siderophore under iron limiting conditions. Rhizobia are also reported to induce systemic resistance and enhance expression of plant defense-related genes, which effectively immunize the plants against pathogens. Seed bacterization with appropriate rhizobial strain leads to elicitation and accumulation of phenolic compounds, isoflavonoid phytoalexins, and activation of enzymes like L-phenylalanine amm...

Chickpea (Cicer arietinum L.) is an important legume food crop grown worldwide and plays signific... more Chickpea (Cicer arietinum L.) is an important legume food crop grown worldwide and plays significant role in restoring soil fertility and sustainable agriculture. However, it is prone to diseases caused by several fungal pathogens which reduce the crop yield. In a pursuit to identify Rhizobium cultures that are efficient for nitrogen fixation and can inhibit some of the soil borne fungal pathogens, 150 chickpea specific Mesorhizobium ciceri isolates developed through isolation from the root nodules and procured from culture collection, HAU, Hisar were screened against Fusarium oxysporum f. sp. ciceri, Ascochyta rabiei, Botrytis cinerea, Sclerotium rolfsii and Macrophomina phaseolina for their antifungal activity. Among them, 10 isolates showed good antagonistic activity and percent inhibition of fungal mycelia ranged from 5-49 %. Promising cultures also exhibited important anti-fungal and plant growth promoting traits such as production of HCN, ammonia, IAA and phosphate solubilisat...

Biofilmed biofertilizers have emerged as a new improved inoculant technology to provide efficient... more Biofilmed biofertilizers have emerged as a new improved inoculant technology to provide efficient nutrient and pest management and sustain soil fertility. In this investigation, development of a Trichoderma viride–Me-sorhizobium ciceri biofilmed inoculant was undertaken, which we hypothesized, would possess more effective biological nitrogen fixing ability and plant growth promoting properties. As a novel attempt, we selected Me-sorhizobium ciceri spp. with good antifungal attributes with the assumption that such inoculants could also serve as biocontrol agents. These biofilms exhibited significant enhancement in several plant growth promoting attributes, including 13–21 % increase in seed germination, production of ammonia, IAA and more than onefold to twofold enhancement in phosphate solubilisation, when compared to their individual partners. Enhancement of 10–11 % in antifungal activity against Fusarium oxysporum f. sp. ciceri was also recorded, over the respective M. ciceri counterparts. The effect of biofilms and the M. ciceri cultures individual on growth parameters of chickpea under pathogen challenged soil illustrated that the biofilms performed at par with the M. ciceri strains for most plant biometrical and disease related attributes. Elicitation of defense related enzymes like L-phenylalanine ammonia lyase, peroxidase and polyphenol oxidase was higher in M. ciceri/biofilm treated plants as compared to uninoculated plants under pathogen challenged soil. Further work on the signalling mechanisms among the partners and their tri-partite interactions with host plant is envisaged in future studies.

Scientific Reports, Apr 20, 2023

Mono-cropping of maize-wheat, mechanical disintegration of soils, and continuous chemical fertili... more Mono-cropping of maize-wheat, mechanical disintegration of soils, and continuous chemical fertilization have deteriorated soil health in the Indo-Gangetic Plains. We studied the long-term impact of pulse-based cropping systems with integrated nutrient management on soil physical and chemical properties and yield sustainability. We evaluated four different cropping systems: (1) maize-wheat (M-W), (2) maize-wheat-mungbean (M-W-Mb), (3) maize-wheat-maize-chickpea (M-W-M-C), (4) pigeonpea-wheat (P-W) each with three degrees of soil fertilization techniques: (1) unfertilized control (CT), (2) inorganic fertilization (RDF), and (3) integrated nutrient management (INM). The field experiment was undertaken in a split-plot design with three replications each year with a fixed layout. P-W and M-W-Mb systems enhanced soil properties such as volume expansion by 9-25% and porosity by 7-9% (p < 0.05) more than M-W, respectively. P-W and M-W-Mb increased soil organic carbon by 25-42% and 12-50% over M-W (RDF). P-W system enhanced water holding capacity and gravimetric moisture content by 10 and 11% (p < 0.05) than M-W. Pulse-based systems (P-W and M-W-Mb) had higher available nitrogen (8-11%), phosphorus (42-73%), and potassium (8-12%) over M-W (p < 0.05). M-W-Mb increased 26% maize yield and 21% wheat yield over M-W (p < 0.05) at the thirteenth crop cycle. P-W system had a higher sustainable yield index (p < 0.05) of wheat over the M-W. Thus, pulse inclusion in the cropping system in combination with INM can enhance physical and chemical properties vis-à-vis sustainable yield index over the cereal-cereal system. Soil physical properties are a significant part of the soil system working and empower to assess the ecosystem sustainability 1, 2. The physical properties of soil as bulk density, soil structure, and water-holding capacity are signs of good soil well-being in the long-run 3. The water-holding capacity of soil is regulated by: (1) pore size distribution, (2) surface area of soil, and (3) aggregate stability. Fundamentally, soil aggregates (macro-and micro-aggregates) minimize organic matter mineralization, sequestering soil organic carbon (SOC) and nutrients 4. Theoretically, increased water-holding capacity, soil moisture content, and aggregate stability are indicators of the positive impact of crop diversification and balanced fertilization on soil health 1, 5. Soil aggregated nutrients strongly influenced by crop management practices that include tillage/mechanical disruption, crop rotation, and fertilization techniques 6. Rice-wheat (9.64 m ha area) and maize-wheat (1.83 m ha area) are the two dominant cropping systems in the Indo-Gangetic plains (IGP) 6, 7. These cropping systems reduced crop productivity and soil ecology because of SOC depletion, macro-and micro-nutrient deficiency, the decline in soil microbial/ biological properties, and groundwater table depletion 8, 9. Pulse crops in the cropping system might reduce soil health deterioration and increase yield sustainability 9. A long-term study indicated that the chickpea yield was more sustainable than the maize 10. Therefore, it is necessary to evaluate the long-term impact of pulses in cropping systems on soil physical and chemical properties and crop yields in the IGP.

Soil and Tillage Research, 2019

We evaluated the long-term impact of zero tillage (ZT) in post-rainy seasons (winter and summer) ... more We evaluated the long-term impact of zero tillage (ZT) in post-rainy seasons (winter and summer) crop/s, crop residue management, and crop diversification on soil aggregation and carbon sequestration. The field experiment (started in 2009) was undertaken in split-plot design for seven consecutive years on a sandy loam soil of Kanpur, India. The experiment comprised of four tillage and crop residue management treatments: PTRconventional tillage (CT) without crop residue (PTR-CT), PTR-ZT without crop residue (PTR-ZT-R), PTR-CT with crop residue incorporation (PTR-CT+R), and PTR-ZT with surface crop residue retention (PTR-ZT + R) in main plot, and three cropping systems: rice-wheat (RW), rice-chickpea (RC), and rice-chickpea-mungbean (RCMb) in subplot. Treatment PTR-ZT + R resulted in 13% (p < 0.05) higher water stable macroaggregate over the PTR-CT. Meantime, PTR-ZT+R increased carbon content in macro-aggregate (28%) and meso-aggregate (39%) over the PTR-CT, because of added carbon through the surface-laden crop residue. The tillage and crop residue management followed the sequence of PTR-ZT+R > PTR-ZT-R > PTR-CT+R > PTR-CT (p < 0.05) across the soil depths for active and passive carbon pools. After seven years, PTR-ZT+R enhanced soil microbial biomass carbon (SMBC) and particulate organic carbon (POC) by 70 and 56% over PTR-CT, respectively. The RCMb and RC rotations increased (p < 0.05) the macro-and meso-aggregates, and aggregate mean weight diameter compared to the RW rotation in both soil depths. Crop rotations had the following trend: RCMb > RC > RW (p < 0.05) for SMBC and POC. Notably, treatment PTR-ZT+R with RCMb or RC rotations largely increased the carbon management index compared to the PTR-CT and RW systems. The structural indices and soil carbon parameters were significantly correlated to the rice grain yield, except microaggregated carbon. Thus, crop diversification with grain legume/s, zero tillage in post rainy season crop/s, and crop residue retention provided not only higher soil aggregation but also increased carbon sequestration in Inceptisol of subtropical humid climate.

Plant Response Mechanisms to Abiotic Stresses [Working Title]

Reduction in biomass and pollen fertility are the two major constraints resulting in poor grain y... more Reduction in biomass and pollen fertility are the two major constraints resulting in poor grain yield in major pulses grown under rainfed agrosystem. Generally, pulses are encountered into both heat and drought stresses during terminal reproductive stages. Though pulses have many adaptive features to counter the adverse effects of various abiotic stresses but yield is substantially reduced when the magnitude of these stresses is very high. The factors have been identified to enhance grain yield under stress environments which include promotion of biomass in the above ground part enabling crops to reserve a maximum amount of photosynthesis and water in the plant system itself before the onset of drought and heat stresses during reproductive stages. Various physiological mechanisms and fertility enhancement components including genetic diversity in key traits have been discussed here to improve yield of pulses under stressed conditions.

Asian Journal of Dairy and Food Research, 2022

Background: Mungbean is consumed as whole, sprouts or dehusked splits, in form of dal. Dal is pre... more Background: Mungbean is consumed as whole, sprouts or dehusked splits, in form of dal. Dal is prepared after removal of outer husk cover and splitting the cotyledons in abrasive emery roller mills to improve esculent properties. In the process of husk removal, milling byproduct, mixture of husk and cotyledon powder, is generated, which is usually utilized as low value cattle feed. The milling byproduct contains bioactive compounds useful for human health. In the study biochemical properties of two mungbean cultivars, namely, Shikha and Virat, were evaluated for whole, dal milling byproduct and its fractions, to explore using milling byproduct of mungbean for potential edible usages. Methods: In this study, mungbean cultivars were milled in abrasive roller after water soaking pre-milling treatment. Milling byproduct was fractionated into three particle sizes, i) greater than 1.0 mm, ii) greater than 0.125 mm and iii) less than 0.125 mm. Biochemical components, viz, protein, phenols, ...

Beneficial Microbes in Agro-Ecology, 2020

Cyanobacteria, also known as blue green algae, are the prokaryotic group of organism which consti... more Cyanobacteria, also known as blue green algae, are the prokaryotic group of organism which constitutes a major part of phytoplankton and a primary colonizer in different habitats. The practical importance of cyanobacteria as a source of nitrogen fertilizer in rice is well recognized (Singh and Singh, 1989) and plays a significant role in sustaining and improving rice field productivity (Rodger et al., 1979; Pabbi, 2008). Earlier it was believed that higher yield was due to nitrogen fixation only. But a number of studies showed that improved yield is not only due to nitrogen fixation but also due to production of growth promoting substances (Venkataraman and Neelakantan, 1967; Marsalek et al., 1992), phosphate solubilising ability (Bisoyi and Singh, 1988), addition of organic matter (Singh and Bisoyi, 1989; Das et al., 1991), pesticide tolerance (Ahmed and Venkataraman, 1973; Kaushik and Venkataraman, 1983, Pabbi International Journal of Current Microbiology and Applied Sciences ISSN...

The world has been confronted with an energy crisis, depletion of fossil fuel and increasing conc... more The world has been confronted with an energy crisis, depletion of fossil fuel and increasing concern of global climate change; therefore, there is a need to find an alternative biological solution which is green and free from pollution. Microalgae are highly diverse, single or multicellular, microscopic photosynthetic organisms and utilize sunlight and carbon dioxide for synthesis of food. Microalgal biomass has been considered to be an important and valuable resource due to appreciable growth rate and high levels of lipids, carbohydrates and other value-added products. Microalgae have been utilized for biofuel production such as biodiesel, bioethanol, biohydrogen and biomethane production over the years. Conservation of genetic resources is an important aspect for every nation. Various conservation techniques are available to conserve the microorganisms. This chapter is mainly focused on conservation of microalgae and application aspect of microalgae in the area of biofuel production.

Indian Journal of Microbiology, 2016

Biofilmed biofertilizers have emerged as a new improved inoculant technology to provide efficient... more Biofilmed biofertilizers have emerged as a new improved inoculant technology to provide efficient nutrient and pest management and sustain soil fertility. In this investigation, development of a Trichoderma viride-Mesorhizobium ciceri biofilmed inoculant was undertaken, which we hypothesized, would possess more effective biological nitrogen fixing ability and plant growth promoting properties. As a novel attempt, we selected Mesorhizobium ciceri spp. with good antifungal attributes with the assumption that such inoculants could also serve as biocontrol agents. These biofilms exhibited significant enhancement in several plant growth promoting attributes, including 13-21 % increase in seed germination, production of ammonia, IAA and more than onefold to twofold enhancement in phosphate solubilisation, when compared to their individual partners. Enhancement of 10-11 % in antifungal activity against Fusarium oxysporum f. sp. ciceri was also recorded, over the respective M. ciceri counterparts. The effect of biofilms and the M. ciceri cultures individual on growth parameters of chickpea under pathogen challenged soil illustrated that the biofilms performed at par with the M. ciceri strains for most plant biometrical and disease related attributes. Elicitation of defense related enzymes like L-phenylalanine ammonia lyase, peroxidase and polyphenol oxidase was higher in M. ciceri/biofilm treated plants as compared to uninoculated plants under pathogen challenged soil. Further work on the signalling mechanisms among the partners and their tripartite interactions with host plant is envisaged in future studies.

Folia microbiologica, Jan 12, 2017

Rhizobia are a group of organisms that are well known for their ability to colonize root surfaces... more Rhizobia are a group of organisms that are well known for their ability to colonize root surfaces and form symbiotic associations with legume plants. They not only play a major role in biological nitrogen fixation but also improve plant growth and reduce disease incidence in various crops. Rhizobia are known to control the growth of many soilborne plant pathogenic fungi belonging to different genera like Fusarium, Rhizoctonia, Sclerotium, and Macrophomina. Antagonistic activity of rhizobia is mainly attributed to production of antibiotics, hydrocyanic acid (HCN), mycolytic enzymes, and siderophore under iron limiting conditions. Rhizobia are also reported to induce systemic resistance and enhance expression of plant defense-related genes, which effectively immunize the plants against pathogens. Seed bacterization with appropriate rhizobial strain leads to elicitation and accumulation of phenolic compounds, isoflavonoid phytoalexins, and activation of enzymes like L-phenylalanine amm...

Chickpea (Cicer arietinum L.) is an important legume food crop grown worldwide and plays signific... more Chickpea (Cicer arietinum L.) is an important legume food crop grown worldwide and plays significant role in restoring soil fertility and sustainable agriculture. However, it is prone to diseases caused by several fungal pathogens which reduce the crop yield. In a pursuit to identify Rhizobium cultures that are efficient for nitrogen fixation and can inhibit some of the soil borne fungal pathogens, 150 chickpea specific Mesorhizobium ciceri isolates developed through isolation from the root nodules and procured from culture collection, HAU, Hisar were screened against Fusarium oxysporum f. sp. ciceri, Ascochyta rabiei, Botrytis cinerea, Sclerotium rolfsii and Macrophomina phaseolina for their antifungal activity. Among them, 10 isolates showed good antagonistic activity and percent inhibition of fungal mycelia ranged from 5-49 %. Promising cultures also exhibited important anti-fungal and plant growth promoting traits such as production of HCN, ammonia, IAA and phosphate solubilisat...

Biofilmed biofertilizers have emerged as a new improved inoculant technology to provide efficient... more Biofilmed biofertilizers have emerged as a new improved inoculant technology to provide efficient nutrient and pest management and sustain soil fertility. In this investigation, development of a Trichoderma viride–Me-sorhizobium ciceri biofilmed inoculant was undertaken, which we hypothesized, would possess more effective biological nitrogen fixing ability and plant growth promoting properties. As a novel attempt, we selected Me-sorhizobium ciceri spp. with good antifungal attributes with the assumption that such inoculants could also serve as biocontrol agents. These biofilms exhibited significant enhancement in several plant growth promoting attributes, including 13–21 % increase in seed germination, production of ammonia, IAA and more than onefold to twofold enhancement in phosphate solubilisation, when compared to their individual partners. Enhancement of 10–11 % in antifungal activity against Fusarium oxysporum f. sp. ciceri was also recorded, over the respective M. ciceri counterparts. The effect of biofilms and the M. ciceri cultures individual on growth parameters of chickpea under pathogen challenged soil illustrated that the biofilms performed at par with the M. ciceri strains for most plant biometrical and disease related attributes. Elicitation of defense related enzymes like L-phenylalanine ammonia lyase, peroxidase and polyphenol oxidase was higher in M. ciceri/biofilm treated plants as compared to uninoculated plants under pathogen challenged soil. Further work on the signalling mechanisms among the partners and their tri-partite interactions with host plant is envisaged in future studies.