Weather-based prediction of anthracnose severity using artificial neural network models     

S. Chakraborty †  R. Ghosh  M. Ghosh  C. D. Fernandes  M. J. Charchar  S. Kelemu 《Plant pathology》2004,53(4):375-386

Data were collected and analysed from seven field sites in Australia, Brazil and Colombia on weather conditions and the severity of anthracnose disease of the tropical pasture legume Stylosanthes scabra caused by Colletotrichum gloeosporioides . Disease severity and weather data were analysed using artificial neural network (ANN) models developed using data from some or all field sites in Australia and/or South America to predict severity at other sites. Three series of models were developed using different weather summaries. Of these, ANN models with weather for the day of disease assessment and the previous 24 h period had the highest prediction success, and models trained on data from all sites within one continent correctly predicted disease severity in the other continent on more than 75% of days; the overall prediction error was 21·9% for the Australian and 22·1% for the South American model. Of the six cross-continent ANN models trained on pooled data for five sites from two continents to predict severity for the remaining sixth site, the model developed without data from Planaltina in Brazil was the most accurate, with >85% prediction success, and the model without Carimagua in Colombia was the least accurate, with only 54% success. In common with multiple regression models, moisture-related variables such as rain, leaf surface wetness and variables that influence moisture availability such as radiation and wind on the day of disease severity assessment or the day before assessment were the most important weather variables in all ANN models. A set of weights from the ANN models was used to calculate the overall risk of anthracnose for the various sites. Sites with high and low anthracnose risk are present in both continents, and weather conditions at centres of diversity in Brazil and Colombia do not appear to be more conducive than conditions in Australia to serious anthracnose development.  相似文献   

Toxico‐kinetics,recovery efficiency and microsomal changes following administration of deltamethrin to black Bengal goats     

Sanis Juliet  Animesh K Chakraborty  Kishori M Koley  Tapan K Mandal  Anjan Bhattacharyya 《Pest management science》2001,57(3):311-319

A study of the toxico‐kinetics, recovery percentage from different substrates, cytotoxicity and role of cytochrome P₄₅₀ and b₅ of liver microsome in the metabolism of deltamethrin were carried out in female black Bengal goat. The ALD₅₀ value of deltamethrin in goat by intravenous route lies between 0.2 and 0.6 mg kg^?1. Intravenous disposition kinetics using a dose of 0.2 mg kg^?1 showed that the maximum blood concentration of deltamethrin was recorded at 0.5 min, followed by rapid decline, and a minimum concentration was detected at 6 min after administration. The following values were obtained : Vd_area 0.148 (± 0.02) litre kg^?1; t_1/2 (α) 0.22 (± 0.02) min; t_1/2 (β) 2.17 (± 0.37) min; K_el 1.05 (± 0.24) min^?1; AUC 4.30(± 0.45) µg min ml^?1; Cl_B 0.05 (± 0.006) litre kg^?1 min^?1; T～B 1.93 (± 0.58); fc 0.40(± 0.05). After 10 min, liver retained the maximum residue, and heart, adrenal gland, kidney, spleen, fat and brain also held the insecticide; liver, fat, heart and spleen retained residue after 30 min, and bone, liver and fat retained residue after 60 min of intravenous administration. Oral absorption of deltamethrin was poor and inconsistent, and approximately 65% of administered dose was recovered from faeces and gastrointestinal contents. The excretion of deltamethrin through urine was meagre, and only 0.01 and 0.013% of the administered dose was recovered after 3 and 5 days of oral administration respectively. All the tissues retained the residue after 3 days; while fat, rumen, reticulum, omasum, abomasum, large and small intestine and bone retained the residue after 5 days of oral administration; and the percentage recoveries were 1.73 and 0.027 respectively. Deltamethrin reduced the level of cytochrome P₄₅₀ content of liver microsomal pellet of goat after 5 days of oral administration. Histopathological examination of liver, kidney, heart, spleen brain and lung sections of treated goats did not reveal any pathological changes. © 2001 Society of Chemical Industry  相似文献   

Phototransformation of the insecticide hydramethylnon in aqueous systems     

Subhasish K. Chakraborty  Anjan Bhattacharyya  Ashim Chowdhury 《Pest management science》1993,37(1):73-77

Sunlight irradiation of hydramethylnon in aqueous media of different pH values resulted in 80-94% transformation within 10h. The rate of disappearance of the insecticide was affected marginally by the initial pH of the reaction medium. After 10 h irradiation, eight photoproducts were formed. Three products were isolated as pure crystalline substances and the structures of two of these (I & III) were characterised by mass and NMR spectroscopy. The reaction mechanisms involved in the formation of photoproducts are discussed.  相似文献   

Detection and cellular location of cross-reactive antigens shared by Camellia sinensis and Bipolaris carbonum     

B.N. Chakraborty  A. Saha 《Physiological and Molecular Plant Pathology》1994,44(6)

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Effect of Water Stress on Biochemical and Physiological Characteristics of Oat Genotypes     

A. Chandra  R. K. Bhatt  L. P. Misra 《Journal of Agronomy and Crop Science》1998,181(1):45-48

Activities of enzymes catalase, peroxidase, and level of total soluble proteins were studied in two genotypes (JHO 884, JHO 888) of oat ( Avena sativa L.) subjected to water stress for 1, 3, and 4 days by withholding water in a pot culture experiment. No change was observed in the level of total soluble proteins at early stage but it increased significantly at higher magnitude of water stress. Increase in catalase activity was noticed in JHO 884 whereas reverse trend was observed in JHO 888 at highest level of stress. The JHO 884 genotype showed increase in peroxidase activity from the first day of water stress. Results suggest that the efficiency level of antioxidant system is found different in these two genotypes.  相似文献   

Phosphorus skipping effect on productivity,profitability and sustainability of rice-wheat cropping systems in Indo-Gangetic plains of India     

Subhash Chandra Tripathi  Subhash Chander  Raj Pal Meena 《Archives of Agronomy and Soil Science》2019,65(8):1134-1146

A field experiment was conducted for eight years at ICAR-Indian Institute of Wheat and Barley Research, Karnal, Haryana, India to study the skipping effect of P application on productivity, profitability and sustainability of rice-wheat cropping system. Rice yield and biomass were 8.35% and 6.6% higher where cowpea was grown after wheat compared to rice-vegetable pea-wheat crop sequence, respectively. Phosphorus application to rice or wheat or both crops exhibited at par rice grain yield, biomass, harvest index. Phosphorus application to both crops or only in rice crop produced maximum and significantly higher wheat yield (4.62 t ha^?1) as compared to P application only to wheat (4.48 t ha^?1). Eight years growing of green gram, cowpea and vegetable pea increased the organic carbon content 42.89, 16.38 and 4.57 %, respectively compared to the initial level. Skipping of P to either crop, by considering 13.5 million ha rice-wheat area, will save approximately Rs 40,500 million (Rs = Indian rupee) or US $ 623 million ($ = Rs 65) per year. Air pollution may be checked, due to saving on diesel in transportation of P fertilizer, to the tune of 60,383 tonnes of CO₂ per year by reducing emission of one of important global warming gas.  相似文献   

Cellulase production by Aspergillus unguis in solid state fermentation     

K.Shruthi  P.Suresh Yadav  B.V.Siva Prasad  M.Subhosh Chandra 《林业研究》2019,(1):205-212

Lignocellulosic substrates are a good carbon source and provide rich growth media for a variety of microorganisms which prodLuce industrially important enzymes. Cellulases are a group of hydrolytic enzymes such as filter paperase (FPase), carboxymethyl cellulase(CMCase) andβ-glucosidase-responsible for release of sugars in the bioconversion of the lignocellulosic biomass into a variety of value-added products. This study examined cellulase production by a newly isolated Aspergillus unguis on individual lignocellulosic substrates in solid state fermentation (SSF). The maximum peak production of enzymes varied from one substrate to another, however,based on the next best solid support and local availability of groundnut fodder supported maximum enzyme yields compared with other solid supports used in this study.Groundnut fodder supported significant production of FPase (5.9 FPU/g of substrate), CMCase (1.1 U/g of substrate) andβ-glucosidase activity (6.5 U/g of substrate) in SSF. Considerable secretion of protein (27.0 mg/g of substrate) on groundnut fodder was recorded. Constant increment of protein content in groundnut fodder due to cultivation of A. unguis is an interesting observation and it has implications for the improvement of nutritive value of groundnut fodder for cattle.  相似文献   

Sorghum ergot can develop without local Claviceps africana inoculum from nearby infected plants     

S. Chakraborty  M. J. Ryley 《Plant pathology》2008,57(3):484-492

Batches of glasshouse-grown flowering sorghum plants were placed in circular plots for 24 h at two field sites in southeast Queensland, Australia on 38 occasions in 2003 and 2004, to trap aerial inoculum of Claviceps africana. Plants were located 20–200 m from the centre of the plots. Batches of sorghum plants with secondary conidia of C. africana on inoculated spikelets were placed at the centre of each plot on some dates as a local point source of inoculum. Plants exposed to field inoculum were returned to a glasshouse, incubated at near-100% relative humidity for 48 h and then at ambient relative humidity for another week before counting infected spikelets to estimate pathogen dispersal. Three times as many spikelets became infected when inoculum was present within 200 m of trap plants, but infected spikelets did not decline with increasing distance from local source within the 200 m. Spikelets also became infected on all 10 dates when plants were exposed without a local source of infected plants, indicating that infection can occur from conidia surviving in the atmosphere. In 2005, when trap plants were placed at 14 locations along a 280 km route, infected spikelets diminished with increasing distance from sorghum paddocks and infection was sporadic for distances over 1 km. Multiple regression analysis showed significant influence of moisture related weather variables on inoculum dispersal. Results suggest that sanitation measures can help reduce ergot severity at the local level, but sustainable management will require better understanding of long-distance dispersal of C. africana inoculum.  相似文献   

Muscle fiber types,growth and development in the whole myotome of cultured Pacific bluefin tuna Thunnus orientalis     

Roy  Bimol Chandra  Ando  Masashi  Nakatani  Masahiro  Okada  Tokihiko  Sawada  Yoshifumi  Itoh  Tomohiro  Tsukamasa  Yasuyuki 《Fisheries Science》2012,78(2):471-483

Following the successful development of Pacific bluefin tuna (PBT) aquaculture, it is of considerable importance to determine the muscle fiber types and their growth patterns for future development. Muscle fiber profiles of dorsal ordinary, lateral ordinary (LO) and dark muscles and their growth patterns in PBT from 3.0 to 54.3 kg body weight were studied. Muscle fibers were histochemically stained for NADH-diaphorase and myosin adenosine triphosphatase activity (mATPase), and immunohistochemically stained with S-58 slow-muscle myosin antibody. All muscle fibers in dorsal and LO muscles showed low NADH-diaphorase activity, and acid-labile (pH 4.0 or 4.3) and alkali-stable mATPase activity. In LO muscle adjacent to dark muscle, three intensities of mATPase activity were observed after acid pre-incubation at pH 4.5 or 5.0, and the activity was related to the muscle fiber diameter. In dark muscle, all small and some large fibers stained intensely for NADH-diaphorase activity, related to their high aerobic metabolism. The high-active fibers with NADH-diaphorase in dark muscle were positive for S-58 antibody. Some large fibers in dark muscle showed intermediate NADH-diaphorase activity and high mATPase activity after alkali pre-incubations. These are fast-twitch oxido-glycolytic fibers in dark muscle and transformed to red muscle fibers with increasing body weight.  相似文献   

Arbuscular Mycorrhizal （AM） Diversity in Prosopis cineraria （L.） Druce Under Arid Agroecosystems     

Neelam Verma Jagadish Chandra Tarafdar Krishna Kant Srivastava Jitendra Panwar 《中国农业科学(英文版)》2008,7(6)

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