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Alakananda Mukherjee - One of the best experts on this subject based on the ideXlab platform.

Koon-hui Wang - One of the best experts on this subject based on the ideXlab platform.

  • eFFects OF Crotalaria juncea On the anhYDROBIOtIc state OF ROTYLENCHULUS RENIFORMIS
    Nematropica, 2012
    Co-Authors: Sharadchandra P. Marahatta, Koon-hui Wang, Brent S. Sipes, Cerruti R. R. Hooks
    Abstract:

    Marahatta, S. P., K.-H. Wang, B. S. Sipes, and C. R. R. Hooks. 2012. Effects of Crotalaria juncea on the anhydrobiotic state of Rotylenchulus reniformis. Nematropica 42:34-40. Although Crotalaria juncea is known to produce allelopathic compounds against many plant-parasitic nematodes, it is unclear if this allelopathic effect suppresses the anhydrobiotic state of reniform nematode, Rotylenchulus reniformis. Two greenhouse experiments were conducted where soil from a fallow pineapple field with a history of reniform nematode infestation was preconditioned by 1) keeping the soil dry (DRY), 2) irrigating (IRR), 3) growing sunn hemp (SH), or 4) growing cowpea (CP) for 3 mo. The conditioning mimicked four different schemes of field conditions that stimulate different reniform nematode survival states. DRY was expected to encourage a non-active state, whereas IRR, SH and CP were expected to encourage active states. At the end of conditioning, soils were either incorporated or not incorporated with sunn hemp foliage. Cowpeas were planted for bioassay. At termination of conditioning, DRY resulted in higher numbers of non-active (anhydrobiotic) nematodes than IRR, SH, and CP (P < 0.05). At termination of the cowpea bioassay, soil incorporation of SH suppressed numbers of reniform nematodes in soils and in bioassay cowpea roots when soil was conditioned with CP, but not in DRY conditioning. Soil incorporation of SH also reduced numbers of reniform nematodes in bioassay cowpea roots when the soil was conditioned with SH. Thus, soil incorporation of SH did not effectively suppress reniform nematodes in their anhydrobiotic state.

  • Influence of organic Crotalaria juncea hay and ammonium nitrate fertilizers on soil nematode communities
    Applied Soil Ecology, 2006
    Co-Authors: Koon-hui Wang, Robert Mcsorley, A. J. Marshall, R. N. Gallaher
    Abstract:

    Comparisonsoforganicandinorganicfertilizereffectsonnematodecommunitiesdependonthespecificorganicfertilizerused. Fieldexperimentswereconductedduring2001and2002inasquash(Cucurbitapepo)agroecosystemtodetermineifapplyingsunn hemp (Crotalaria juncea) hayas an organicfertilizer improved nematode communities involved insoil nutrientcycling compared toanequivalentNrate(100 kg N/ha)ofammoniumnitrate.Fertilizersourcehadminimaleffectonnematodecommunitiesin2001 when treatments were applied after a winter cover crop of oats (Avena sativa), but differences (P � 0.05) between the fertilizer sourcesoccurredin2002whennowintercovercroppingprecededsquash.Fertilizationwithsunnhemphayincreasedabundanceof the bacterivore guilds Ba1 and Ba2, and increased fungivores at the end of the experiment. Compared to ammonium nitrate, fertilization with sunn hemp hay resulted in a community with lower maturity index, higher enrichment index, and lower channel index, consistent with a disturbed and nutrient-enriched soil food web undergoing bacterial decomposition. Sunn hemp hay occasionally stimulated omnivorous nematodes, but suppressed plant-parasitic nematodes relative to ammonium nitrate fertilizer. Increasing the sunn hemp hay rate to 200 kg N/ha increased the abundance of bacterivores, fungivores, and predatory nematodes, and total nematode abundance compared to hay at 100 kg N/ha. Fertilization with ammonium nitrate increased the percentage of herbivores,butreducedpercentageandabundanceofomnivores.Inconclusion,sunnhempfertilizermaintainedgreaternumbersof nematodes involved in nutrient cycling as compared to ammonium nitrate. # 2005 Elsevier B.V. All rights reserved.

  • Effect of Crotalaria juncea Amendment on Squash Infected with Meloidogyne incognita.
    Journal of nematology, 2004
    Co-Authors: Koon-hui Wang, Robert Mcsorley, R. N. Gallaher
    Abstract:

    Two greenhouse experiments were conducted to examine the effect of Crotalaria juncea amendment on Meloidogyne incognita population levels and growth of yellow squash (Cucurbita pepo). In the first experiment, four soils with a long history of receiving yard waste compost (YWC+), no-yard-waste compost (YWC-), conventional tillage, or no-tillage treatments were used; in the second experiment, only one recently cultivated soil was used. Half of the amount of each soil received air-dried residues of C. juncea as amendment before planting squash, whereas the other half did not. Crotalaria juncea amendment increased squash shoot and root weights in all soils tested, except in YWC+ soil where the organic matter content was high without the amendment. The amendment suppressed the numbers of M. incognita if the inoculum level was low, and when the soil contained relatively abundant nematode-antagonistic fungi. Microwaved soil resulted in greater numbers of M. incognita and free-living nematodes than frozen or untreated soil, indicating nematode-antagonistic microorganisms played a role in nematode suppression. The effects of C. juncea amendment on nutrient cycling were complex. Amendment with C. juncea increased the abundance of free-living nematodes and Harposporium anguillulae, a fungus antagonistic to them in the second experiment but not in the first experiment. Soil histories, especially long-term yard waste compost treatments that increased soil organic matter, can affect the performance of C. juncea amendment.

  • Nematode community changes associated with decomposition of Crotalaria juncea amendment in litterbags
    Applied Soil Ecology, 2004
    Co-Authors: Koon-hui Wang, Robert Mcsorley, A. J. Marshall, R. N. Gallaher
    Abstract:

    Effects of sunn hemp (Crotalaria juncea) residue (C:N = 18.9:1) decomposition on the dynamics of free-living nematodes involved in soil nutrient cycling were examined in plots planted with sweet corn (Zea mays). Abundance of bacterivorous and fungivorous nematodes in litterbags containing sunn hemp residues peaked at 14 days after burial (DAB) followed by increase of omnivorous nematodes at 28 DAB. Another peak of fungivorous nematodes occurred at 56 DAB. A succession of bacterivorous and fungivorous nematodes was observed in the litterbags. Enhancement of predatory nematode abundance by sunn hemp residues was not significant, but abundance of herbivorous nematodes appeared to respond to the increase in crop biomass over time. Although sunn hemp had great impact on the percentages of nematode trophic groups, several nematode fauna indices had reverted by 70 DAB to values found in untreated soil. Succession patterns of the nematode trophic groups and community indices in this sunn hemp-amended soil are consistent with a food web response to disturbance from an N-rich resource. The nematode succession dynamics suggested that decomposition of sunn hemp material occurred rather quickly (within 2 weeks after burial), which is consistent with data on weight loss of the residue. These results provide insight into efficient use of an organic residue to optimize succession of nematodes involved in decomposition, and to provide a way to maintain enrichment of the soil food web.

  • Effect of Crotalaria juncea Amendment on Nematode Communities in Soil with Different Agricultural Histories.
    Journal of nematology, 2003
    Co-Authors: Koon-hui Wang, Robert Mcsorley, R. N. Gallaher
    Abstract:

    Effect of sunn hemp (Crotalaria juncea) hay amendment on nematode community structure in the soil surrounding roots of yellow squash (Cucurbita pepo) infected with root-knot nematodes was examined in two greenhouse experiments. Soils were from field plots treated long-term (LT) with yard-waste compost or no yard-waste compost in LT experiment, and from a short-term (ST) agricultural site in ST experiment. Soils collected were either amended or not amended with C. juncea hay. Nematode communities were examined 2 months after squash was inoculated with Meloidogyne incognita. Amendment increased (P < 0.05) omnivorous nematodes in both experiments but increased only bacterivorous nematodes in ST experiment (P < 0.05), where the soil had relatively low organic matter (

R. N. Gallaher - One of the best experts on this subject based on the ideXlab platform.

  • Influence of organic Crotalaria juncea hay and ammonium nitrate fertilizers on soil nematode communities
    Applied Soil Ecology, 2006
    Co-Authors: Koon-hui Wang, Robert Mcsorley, A. J. Marshall, R. N. Gallaher
    Abstract:

    Comparisonsoforganicandinorganicfertilizereffectsonnematodecommunitiesdependonthespecificorganicfertilizerused. Fieldexperimentswereconductedduring2001and2002inasquash(Cucurbitapepo)agroecosystemtodetermineifapplyingsunn hemp (Crotalaria juncea) hayas an organicfertilizer improved nematode communities involved insoil nutrientcycling compared toanequivalentNrate(100 kg N/ha)ofammoniumnitrate.Fertilizersourcehadminimaleffectonnematodecommunitiesin2001 when treatments were applied after a winter cover crop of oats (Avena sativa), but differences (P � 0.05) between the fertilizer sourcesoccurredin2002whennowintercovercroppingprecededsquash.Fertilizationwithsunnhemphayincreasedabundanceof the bacterivore guilds Ba1 and Ba2, and increased fungivores at the end of the experiment. Compared to ammonium nitrate, fertilization with sunn hemp hay resulted in a community with lower maturity index, higher enrichment index, and lower channel index, consistent with a disturbed and nutrient-enriched soil food web undergoing bacterial decomposition. Sunn hemp hay occasionally stimulated omnivorous nematodes, but suppressed plant-parasitic nematodes relative to ammonium nitrate fertilizer. Increasing the sunn hemp hay rate to 200 kg N/ha increased the abundance of bacterivores, fungivores, and predatory nematodes, and total nematode abundance compared to hay at 100 kg N/ha. Fertilization with ammonium nitrate increased the percentage of herbivores,butreducedpercentageandabundanceofomnivores.Inconclusion,sunnhempfertilizermaintainedgreaternumbersof nematodes involved in nutrient cycling as compared to ammonium nitrate. # 2005 Elsevier B.V. All rights reserved.

  • Effect of Crotalaria juncea Amendment on Squash Infected with Meloidogyne incognita.
    Journal of nematology, 2004
    Co-Authors: Koon-hui Wang, Robert Mcsorley, R. N. Gallaher
    Abstract:

    Two greenhouse experiments were conducted to examine the effect of Crotalaria juncea amendment on Meloidogyne incognita population levels and growth of yellow squash (Cucurbita pepo). In the first experiment, four soils with a long history of receiving yard waste compost (YWC+), no-yard-waste compost (YWC-), conventional tillage, or no-tillage treatments were used; in the second experiment, only one recently cultivated soil was used. Half of the amount of each soil received air-dried residues of C. juncea as amendment before planting squash, whereas the other half did not. Crotalaria juncea amendment increased squash shoot and root weights in all soils tested, except in YWC+ soil where the organic matter content was high without the amendment. The amendment suppressed the numbers of M. incognita if the inoculum level was low, and when the soil contained relatively abundant nematode-antagonistic fungi. Microwaved soil resulted in greater numbers of M. incognita and free-living nematodes than frozen or untreated soil, indicating nematode-antagonistic microorganisms played a role in nematode suppression. The effects of C. juncea amendment on nutrient cycling were complex. Amendment with C. juncea increased the abundance of free-living nematodes and Harposporium anguillulae, a fungus antagonistic to them in the second experiment but not in the first experiment. Soil histories, especially long-term yard waste compost treatments that increased soil organic matter, can affect the performance of C. juncea amendment.

  • Nematode community changes associated with decomposition of Crotalaria juncea amendment in litterbags
    Applied Soil Ecology, 2004
    Co-Authors: Koon-hui Wang, Robert Mcsorley, A. J. Marshall, R. N. Gallaher
    Abstract:

    Effects of sunn hemp (Crotalaria juncea) residue (C:N = 18.9:1) decomposition on the dynamics of free-living nematodes involved in soil nutrient cycling were examined in plots planted with sweet corn (Zea mays). Abundance of bacterivorous and fungivorous nematodes in litterbags containing sunn hemp residues peaked at 14 days after burial (DAB) followed by increase of omnivorous nematodes at 28 DAB. Another peak of fungivorous nematodes occurred at 56 DAB. A succession of bacterivorous and fungivorous nematodes was observed in the litterbags. Enhancement of predatory nematode abundance by sunn hemp residues was not significant, but abundance of herbivorous nematodes appeared to respond to the increase in crop biomass over time. Although sunn hemp had great impact on the percentages of nematode trophic groups, several nematode fauna indices had reverted by 70 DAB to values found in untreated soil. Succession patterns of the nematode trophic groups and community indices in this sunn hemp-amended soil are consistent with a food web response to disturbance from an N-rich resource. The nematode succession dynamics suggested that decomposition of sunn hemp material occurred rather quickly (within 2 weeks after burial), which is consistent with data on weight loss of the residue. These results provide insight into efficient use of an organic residue to optimize succession of nematodes involved in decomposition, and to provide a way to maintain enrichment of the soil food web.

  • Effect of Crotalaria juncea Amendment on Nematode Communities in Soil with Different Agricultural Histories.
    Journal of nematology, 2003
    Co-Authors: Koon-hui Wang, Robert Mcsorley, R. N. Gallaher
    Abstract:

    Effect of sunn hemp (Crotalaria juncea) hay amendment on nematode community structure in the soil surrounding roots of yellow squash (Cucurbita pepo) infected with root-knot nematodes was examined in two greenhouse experiments. Soils were from field plots treated long-term (LT) with yard-waste compost or no yard-waste compost in LT experiment, and from a short-term (ST) agricultural site in ST experiment. Soils collected were either amended or not amended with C. juncea hay. Nematode communities were examined 2 months after squash was inoculated with Meloidogyne incognita. Amendment increased (P < 0.05) omnivorous nematodes in both experiments but increased only bacterivorous nematodes in ST experiment (P < 0.05), where the soil had relatively low organic matter (

Ratna Dutta - One of the best experts on this subject based on the ideXlab platform.

Fabrizio Ginaldi - One of the best experts on this subject based on the ideXlab platform.

  • sunngro a new crop model for the simulation of sunn hemp Crotalaria juncea l grown under alternative management practices
    Biomass & Bioenergy, 2021
    Co-Authors: A Parenti, G Cappelli, Walter Zegadalizarazu, Carlos Martin Sastre, Myrsini Christou, Andrea Monti, Fabrizio Ginaldi
    Abstract:

    Abstract Sunn hemp (Crotalaria juncea L.) is a fast growing, drought tolerant legume crop with potential as a biomass feedstock for advanced biofuels in Southern Europe, grown in either a single or double crop system. This study presents a new simulation model, SunnGro, which reproduces sunn hemp productivity, while providing a detailed description of leaf/branch size heterogeneity and its evolution during the vegetative season. The model was calibrated and validated using 20 field datasets collected from 2016 to 2018 in Greece, Spain, and Italy under non-limiting soil water conditions. High correlation between the simulated and measured values of branch number (R2 = 0.80), leaf number (R2 = 0.92), and biomass accumulation (0.67