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51.
P. Melloy E. Aitken J. Luck S. Chakraborty F. Obanor 《European journal of plant pathology / European Foundation for Plant Pathology》2014,140(1):19-37
Despite recent reports advancing our understanding of climate change on plant diseases, uncertainty remains concerning how host and pathogen interactions are changed by increases in atmospheric carbon-dioxide (CO2) and temperature. This study has observed crown rot inoculated and non-inoculated plants in three glasshouse environments comprising ambient CO2 with ambient temperature (E1), elevated CO2 with ambient temperature (E2) and elevated CO2 with warm temperatures (E3). The proportion of crown rot infected tillers (incidence), length of stem browning (severity) and biomass of Fusarium pseudograminearum in 16 wheat genotypes was destructively assessed at node development, anthesis, soft dough and crop maturity. Mean incidence, severity and Fusarium biomass was greater in E2, and all three measurements increased at a faster rate across plant development stages; E1 showed the lowest mean incidence and severity. Incidence and severity at each development stage was dependent on the environment each genotype was grown. The influence of genotype on Fusarium biomass at each development stage however was not seen to be dependent on environment. Irrespective of genotype plants with greater severity or relative Fusarium biomass showed lower plant dry weight at crop maturity in all environments with exception to E3, where CR severity did not exert a cost to plant dry weight. These results may allude to plant maturity and temperature-dependent resistance as effective mechanisms in building resistance to crown rot. Regardless of temperature, if crown rot symptoms and Fusarium biomass are to increase at elevated CO2 there is potential for a loss in crop production capability while boosting inoculum in crop stubble. 相似文献
52.
Debashis Chakraborty Shantha Nagarajan V.K. Gupta R.N. Garg A. Sarkar K.S. Sundara Sarma 《Agricultural Water Management》2008,95(12):1323-1334
Mulching is one of the important agronomic practices in conserving the soil moisture and modifying the soil physical environment. Wheat, the second most important cereal crop in India, is sensitive to soil moisture stress. Field experiments were conducted during winter seasons of 2004-2005 and 2005-2006 in a sandy loam soil to evaluate the soil and plant water status in wheat under synthetic (transparent and black polyethylene) and organic (rice husk) mulches with limited irrigation and compared with adequate irrigation with no mulch (conventional practices by the farmers). Though all the mulch treatments improved the soil moisture status, rice husk was found to be superior in maintaining optimum soil moisture condition for crop use. The residual soil moisture was also minimum, indicating effective utilization of moisture by the crop under RH. The plant water status, as evaluated by relative water content and leaf water potential were favourable under RH. Specific leaf weight, root length density and dry biomass were also greater in this treatment. Optimum soil and canopy thermal environment of wheat with limited fluctuations were observed under RH, even during dry periods. This produced comparable yield with less water use, enhancing the water use efficiency. Therefore, it may be concluded that under limited irrigation condition, RH mulching will be beneficial for wheat as it is able to maintain better soil and plant water status, leading to higher grain yield and enhanced water use efficiency. 相似文献
53.
Debarati Bhaduri T.J. Purakayastha Debashis Chakraborty K. Chakraborty Man Singh 《Archives of Agronomy and Soil Science》2018,64(1):132-145
We studied few soil physical indicators after eighth cropping cycle of rice-wheat. The experiment was laid out in split-split plot design with two tillage (rice: puddling vs. non-puddling; wheat: conventional tillage vs. no-tillage), three water management (rice: submergence vs. drainage; wheat: five/three/two irrigations) and nine nutrient (N) management treatments (inorganic vs. integrated nutrient management). The bulk density (t m?3) in non-puddled soil (1.33) was significantly less than puddled soil (1.59); while mean weight diameter (0.55 mm) and saturated hydraulic conductivity (0.43 cm h?1) were higher in the former treatment. Irrigation after 3-days of drainage was found to enhance soil aggregation (0.54 mm) and moisture retention (71.6%) during rice. No-tillage in wheat had overall positive impact. Organic sources of nutrients increased soil water retention (biofertilizer for rice), water conductivity and aggregate stability (combined organics for rice and wheat). Interactions between (tillage × N), (water × N), (tillage × water) revealed crop-wise variations. The saturated hydraulic conductivity and soil aggregation for rice; and bulk density, water retention and saturated hydraulic conductivity for wheat were identified as sensitive soil physical indicators. We suggest an effective combination of no tillage and intermittent irrigation with integrated nutrient management for sustaining soil physical quality in rice-wheat rotation. 相似文献
54.
Dipanwita Haldar K. R. Manjunath Sushma Panigrahy Varunika Jain R. S. Gopalan Mukesh Khullar Manab Chakraborty J. S. Parihar 《Paddy and Water Environment》2015,13(4):343-352
Bringing green revolution in eastern India (BGREI) is an initiative of Department of Agriculture and Co-operation (DAC) Ministry of Agriculture (MoA), Govt. of India with the aim of increasing crop productivity through improved inputs and package of practices in seven states of eastern India comprising the low productivity zones. The current study aimed at assessment of the BGREI plots with respect to crop vigour variability using space-based observations. Synthetic aperture radar (SAR) data were used to assess the rice crop growth pattern and vigour through change in backscatter response. A SAR-based methodology was developed to evaluate the effect of BGREI initiative in the state of Odisha. The peak biomass, an indicator of crop vigour was 15–30 % higher in BGREI plots compared to the controlled plots. The improvement was higher in traditionally low productivity rainfed zones. Uniformity in growth in terms of growth rate, transplantation time and duration was observed in BGREI plots. The positive effect of BGREI in Odisha indicates that BGREI may be a breakthrough in improving rice productivity in low productivity zones of eastern India. 相似文献
55.
Kaomud Tyagi Vikas Kumar Devkant Singha Rajasree Chakraborty 《Journal of insect science (Online)》2015,15(1)
South East Asia pest thrips species, Thrips parvispinus (Karny), is a serious pest on a number of agricultural and horticultural crops in a number of plant families. Based on an integrated approach of morphology and DNA barcoding, invasion of this serious pest is reported first time from India on papaya plantations. Molecular data have corroborated with the morphological identification. Haplotyping data suggested that the Indonesia may be a probable source of invasion of this pest to India. 相似文献
56.
Enrichment of eicosapentaenoic acid from sardine oil with Delta5-olefinic bond specific lipase from Bacillus licheniformis MTCC 6824 总被引:1,自引:0,他引:1
Lipase derived from Bacillus licheniformis MTCC 6824 was purified to homogeneity by anion exchange chromatography on Amberlite IRA 410 (Cl-) and gel filtration using Sephadex G-100 as judged by denaturing polyacrylamide gel electrophoresis. The purified lipase was used for hydrolysis of triacylglycerol in sardine oil to enrich Delta5-polyunsaturated fatty acids (Delta5-PUFAs) namely, arachidonic acid (5,8,11,14-eicosatetraenoic acid, ARA, 20:4n-6) and eicosapentaenoic acid (5,8,11,14,17-eicosapentaenoic acid, EPA, 20:5n-3). The individual fatty acids were determined as fatty acid methyl esters (FAMEs) by gas-liquid chromatography and gas chromatography-mass spectroscopy as FAMEs and N-acyl pyrrolidides. The enzyme exhibited hydrolytic resistance toward ester bonds of Delta5-PUFAs as compared to those of other fatty acids and was proved to be effective for increasing the concentration of EPA and ARA from sardine oil. Utilizing this fatty acid specificity, EPA and ARA from sardine oil were enriched by lipase-mediated hydrolysis followed by urea fractionation at 4 degrees C. The purified lipase produced the highest degree of hydrolysis for SFAs and MUFAs (81.5 and 72.3%, respectively, from their initial content in sardine oil) after 9 h. The profile of conversion by lipase catalysis showed a steady increase up to 6 h and thereafter plateaued down. Lipase-catalyzed hydrolysis of sardine oil followed by urea adduction with methanol provided free fatty acids containing 55.4% EPA and 5.8% ARA, respectively, after complexation of saturated and less unsaturated fatty acids. The combination of enzymatic hydrolysis and urea complexation proved to be a promising method to obtain highly concentrated EPA and ARA from sardine oil. 相似文献
57.
S Chakraborty R Knoche H Schulze DC Rubie D Dobson NL Ross RJ Angel 《Science (New York, N.Y.)》1999,283(5400):362-365
Rates of cation diffusion (magnesium, iron, and nickel) have been determined in olivine and its high-pressure polymorph, wadsleyite, at 9 to 15 gigapascals and 1100 degrees to 1400 degreesC for compositions that are relevant to Earth's mantle. Diffusion in olivine becomes strongly dependent on composition at high pressure. In wadsleyite, diffusion is one to two orders of magnitude faster than in olivine, depending on temperature. Homogenization of mantle heterogeneities (chemical mixing) and mineral transformations involving a magnesium-iron exchange will therefore occur considerably faster in the transition zone than at depths of less than 410 kilometers. 相似文献
58.
Kajal Chakraborty Rekha Devi Chakraborty E V Radhakrishnan Koyadan Kizhakedath Vijayan 《Aquaculture Research》2010,41(10):e393-e403
Three different life stages of spiny lobster larvae (phyllosoma) of Panulirus homarus were fed A1‐Selco‐enriched Artemia in two culture treatments, one with the microalgae Nannochloropsis salina (green water) and the other without the microalgae (clear water) to assess the ability to manipulate their fatty acid composition. Phyllosoma fed with 3‐h A1‐Selco‐enriched Artemia salina attained Stage VIII (5.3 mm) and Stage V (3.4 mm) in 42 days in the green and clear water treatments respectively. The higher content of the essential fatty acids in N. salina (eicosapentaenoic acid, 25.8%; arachidonic acid, 9.5%; and docosahexaenoic acid, 4.2%) in the green water system increased the fatty acid content of the live food Artemia, and ultimately the phyllosoma. In spite of phyllosoma being fed with enriched Artemia in the clear water system, the total polyunsaturated fatty acid content of the early (Stages I–III) and mid stage (Stages IV–V) phyllosoma were significantly smaller (18.8% and 14.6% respectively) (P<0.05) than in the green water system (25.3% and 21.2% respectively). These results indicate the positive role of the microalgae in boosting the essential fatty acid content of lobster larvae. 相似文献
59.
Setu Chakraborty Trung Cao Ahmed Hossain Hajarooba Gnanagobal Ignacio Vasquez Danny Boyce Javier Santander 《Journal of fish diseases》2019,42(7):1057-1064
Lumpfish (Cyclopterus lumpus), a native fish of the North Atlantic Ocean, is utilized as cleaner fish to biocontrol sea lice infestations in Atlantic salmon aquaculture. However, bacterial infections are affecting cleaner fish performance. Vibrio anguillarum, the aetiological agent of vibriosis, is one of the most frequent bacterial infections in lumpfish, and effective vaccine programmes against this pathogen have been identified as a high priority for lumpfish. Vibrogen‐2 is a commercial polyvalent bath vaccine that contains formalin‐inactivated cultures of V. anguillarum serotypes O1 and O2, and Vibrio ordalii. In this study, we evaluated Vibrogen‐2 efficacy in lumpfish against a local isolated V. anguillarum strain. Two groups of 125 lumpfish were bath‐immunized, bath‐boost‐immunized at four weeks post‐primary immunization, and intraperitoneally (i.p.) boost‐immunized at eight weeks post‐primary immunization. The control groups were i.p. mock‐immunized with PBS. Twenty‐seven weeks post‐primary immunization, the fish were i.p. challenged with 10 or 100 times the V. anguillarum J360 LD50 dose. After the challenge, survival was monitored daily, and samples of tissues were collected at ten days post‐challenge. Commercial vaccine Vibrogen‐2 reduced V. anguillarum tissue colonization and delayed mortality but did not confer immune protection to C. lumpus against the V. anguillarum i.p. challenge. 相似文献
60.
Subhasish K Chakraborty Anjan Bhattacharya Ashim Chowdhury 《Pest management science》1999,55(9):943-948
Residual fate and behaviour of the herbicide oxadiazon in Kalyani soil, paddy straw and grain were studied under subtropical conditions, in West Bengal following application @ 1 kg and 2 kg ha−1. Dissipation of oxadiazon in soil followed first-order kinetics and DT50 values ranged from 44 to 45 days. Residues at harvest in paddy grains and straw were also studied. Degradation of oxadiazon after 60 days of incubation at 28(± 1) °C in alluvial soil at water holding capacity yielded 10 metabolites of which four were characterised by spectroscopy. © 1999 Society of Chemical Industry 相似文献