194 research outputs found
Effect of deficit irrigation on raised bed wheat cultivation
The experiment was
conducted during Rabi season of 2015-2016
and 2016-2017 at the Regional Agricultural
Research station, BARI, Ishurdi, Pabna,
Bangladesh, to determine the water
requirements of wheat on raised bed and the
effect of different deficit irrigation on yield,
water use efficiency and applied water
productivity under raised bed wheat. This
study consisted of following irrigation
treatments: T1 = Irrigations up to 100% field
capacity (FC) at crown root initiation (CRI),
botting and grain filling stages (flat bed), T2
= Irrigations up to 100% FC at CRI, botting
and grain filling stages on raised bed, T3 =
Irrigations up to 80% FC at CRI, botting
and grain filling stages on raised bed and T4
= Irrigations up to 60% FC at CRI, botting
and grain filling stages on raised bed and
laid out in a randomize complete block
design with three replications.The result
showed that significant effect of irrigation
treatments were observed on plant height,
spike per m2 and grain yield. Highest grain
yield (4.66 t/ha) was obtained from
treatment, irrigations up to 100% FC at CRI,
botting and grain filling stages on raised
bed, followed by irrigation up to 100% FC
at same stages on flat bed. At raised bed
wheat cultivation saving 14.30% water with
increasing 15.66% grain yield than flat bed.
Besides, comparing deficit irrigation (20%
and 40% of full irrigation) and full irrigation
condition on raised bed seeding system
water use could be reduced about 4.18% to
5.57%, while scarifying 18.20% to 32.33%
grain yield, where reduced 14.17% to
27.54% water use efficiency. Maximum
applied water productivity 1.81 kg m-3 was
observed in raised bed full irrigation
condition. The rate of daily evaporation
started to increase as the temperature started
to rise and humidity started to decrease
during the crop growing period. The results
will be helpful for taking policy decision
regarding efficient irrigation and water
management under prevailing water scarce
situation
Population Vulnerability to Biannual Cholera Outbreaks and Associated Macro-Scale Drivers in the Bengal Delta
The highly populated floodplains of the Bengal Delta have a long history of endemic and epidemic cholera outbreaks, both coastal and inland. Previous studies have not addressed the spatio-temporal dynamics of population vulnerability related to the influence of underlying large-scale processes. We analyzed spatial and temporal variability of cholera incidence across six surveillance sites in the Bengal Delta and their association with regional hydroclimatic and environmental drivers. More specifically, we use salinity and flood inundation modeling across the vulnerable districts of Bangladesh to test earlier proposed hypotheses on the role of these environmental variables. Our results show strong influence of seasonal and interannual variability in estuarine salinity on spring outbreaks and inland flooding on fall outbreaks. A large segment of the population in the Bengal Delta floodplains remain vulnerable to these biannual cholera transmission mechanisms that provide ecologic and environmental conditions for outbreaks over large geographic regions
Environmental Factors Influencing Epidemic Cholera
Cholera outbreak following the earthquake of 2010 in Haiti has reaffirmed that the disease is a major public health threat. Vibrio cholerae is autochthonous to aquatic environment, hence, it cannot be eradicated but hydroclimatology-based prediction and prevention is an achievable goal. Using data from the 1800s, we describe uniqueness in seasonality and mechanism of occurrence of cholera in the epidemic regions of Asia and Latin America. Epidemic regions are located near regional rivers and are characterized by sporadic outbreaks, which are likely to be initiated during episodes of prevailing warm air temperature with low river flows, creating favorable environmental conditions for growth of cholera bacteria. Heavy rainfall, through inundation or breakdown of sanitary infrastructure, accelerates interaction between contaminated water and human activities, resulting in an epidemic. This causal mechanism is markedly different from endemic cholera where tidal intrusion of seawater carrying bacteria from estuary to inland regions, results in outbreaks
Effect of solvent pre-treatment on the physicochemical, thermal profiles and morphological behavior of mangifera pajang seed fat
In this work, the effect of solvent pre-treatment (hexane, petroleum ether and ethanol) on the physicochemical, thermal and morphology behavior of Mangifera pajang seed fat (MPSF) were investigated. The results showed that the yield, physicochemical, and crystalline structures of the MPSF were significantly (p<0.05) influenced by the extraction solvents. Hexane gave the highest fat yield (7.67%) with low unsaturation value (52.13 g iodine/g) compared with petroleum ether and ethanol. Hexane MPSF also had low oxidation rate (peroxide value of 1.1 mEq/g). Both non-stabilized and stabilized hexane MPSF showed a single melting endothermic peak at high temperature with onset, maximum peak and offset temperature of 16.23 ËšC-18.21 ËšC, 28.22 ËšC-31.25 ËšC and 34.85 ËšC-39.58 ËšC, respectively. Hexane MPSF crystallized rapidly at high temperature with single maximum peak starting at 16.51 ËšC-16.68 ËšC and ending at 0.23 ËšC-1.13 ËšC. In comparison with ethanol extract, hexane MPSF demonstrated a compact crystalline structure with a large densely packed center. MPSF exhibited similar melting and morphological behavior to mango kernel fat and commercial cocoa butter. These results suggested that hexane was the best solvent for the extraction of MPSF. This fat also has the potential to be applied as a cocoa butter alternative fat
Characteristics of rambutan (Nephelium lappaceum L.) seed fat fractions and their potential application as cocoa butter improver
The utilization of rambutan seed (Nephelium Lappaceum L.) to produce fat (RSF) and its fractionation could be one of the solutions for better waste management and for ensuring
its sustainable utilization. In this study, RSF was fractionated by two-stage acetone fractionation and their physicochemical properties such as fatty acid compositions, iodine value (IV), free fatty acid (FFA), slip melting point (SMP), and solid fat content (SFC) were investigated. The solid fraction-III (F2-S) exhibited the highest SMP (49.03°C) and lowest IV (27.57 g I2/100 g). The major fatty acids in all solid fractions were stearic (15.1- 21.6%), oleic (25.0-35.5%), and arachidic (42.7-46.9%) acids. The SFC of F2-S at 20°C
(78.57%) and 35°C (22.95%) were found to be higher than solid fraction-I (F1-S),
indicating a harder solid fraction. This study revealed that by performing fractionation of
RSF, a cocoa butter improvers (CBI) could be prepared by blending them with other fats
that have the potential to be utilized in chocolate manufacturing in tropical countries
Changes in microstructures of rambutan seed and the quality of its fat during drying
The application of pre-treatment on oilseeds prior to extraction process may exert undesirable impact towards the quality of oils as well as microstructures of seed. The objectives of this study were to evaluate the efects of three drying methods on the microstructures of rambutan seeds and its efects on physicochemical properties of rambutan seed fat (RSF). The fats that being pre-treated with three diferent drying methods showed shrinkage or alteration of porous structure in terms of size, shape, and diameter. The diferences between the RSF pre-treated with oven-, freeze-, and cabinet drying RSF were in fatty acids (oleic and arachidic acids), and free fatty acid (1.56–1.80 mg KOH/g fat). From the results obtained, the useful information regarding to the efects of pre-treatment on RSF, which is a potent ingredient to be used as a cocoa butter substitute in the formulation of chocolate in the confectionery industries. Moreover, the outcomes of this work able to provide information for better grasp about the correlation of drying methods and quality of RSFs, as well as its applications in other food industries
Effects of Honey-Spices Marination on Polycyclic Aromatic Hydrocarbons and Heterocyclic Amines Formation in Gas-Grilled Beef Satay
The effects of honey-spices marination on simultaneous formation of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs) in gas-grilled beef satay were investigated at different grilling temperatures (150 °C, 250 °C, and 350 °C). Beef satay samples used in this study were prepared using two types of honey-spices marination (Apis mellifera-spices and Trigona sp.-spices). Quantifications of fifteen PAHs using high performance liquid chromatography with fluorescence detection (HPLC-FLD) and nine HCAs using liquid chromatography tandem-mass spectrometry (LC–MS/MS) were performed with gradient programme. Results on PAHs and HCAs in marinated samples were compared with control. Highest concentrations (p < 0.05) of PAHs (marinated beef satay) and HCAs (control) were detected at 350 °C. The most prominent PAH and HCA were phenanthrene (24.61–84.36 ng/g) and 9H-pyrido-[4,3-b]indole (Norharman) (2.67–393.89 ng/g). Marination significantly (p < 0.05) reduced naphthalene, fluorene, pyrene, 2-amino-9H-pyrido[2,3-b]indole (AαC), 1-methyl-9H-pyrido-[4,3-b]indole (Harman), and Norharman in gas-grilled beef satay across all temperatures. Overall, inverse quantitative profiles of PAHs and HCAs formation were observed in marinated gas-grilled beef satay
Chitosan biostimulant controls infection of cucumber by Phytophthora capsici through suppression of asexual reproduction of the pathogen
The biopolymer chitosan is a derivative of chitin, which can promote plant growth and protect plants from phytopathogens. This study aimed to evaluate the efficacy of chitosan as a biostimulant and a biorational agent to protect cucumber plants from damping-off disease caused by Phytophthora capsici. Cucumber seeds were treated with a range of chitosan concentrations, viz. 0, 125, 250, and 500 ppm, to evaluate effect on seed germination and fresh root and shoot weight of the seedlings. Chitosan significantly (p ≤ 0.05) enhanced seed germination and root and shoot growth of cucumber in a dose-dependent manner up to 500 ppm. Application of in vitro chitosan suspension onto P. capsici mycelial plug suppressed growth of mycelia, formation of sporangia, and release of P. capsici zoospores at 125–500 ppm concentrations. Cucumber seedlings from chitosan-treated seeds showed enhanced resistance to damping-off disease caused by P. capsici compared to untreated control. Cucumber seedlings from 500 ppm chitosan seed treatment showed 100% disease resistance against damping off caused by P. capsici. These results suggest that chitosan could be used as a natural and environmentally safe alternative to a synthetic growth promoter and pesticide for sustainable production of cucumber
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