Nitric oxide fumigation delays mango fruit ripening

Hard mature green Kensington Pride mango fruit were fumigated with 0, 5, 10, 20 and 40 µL.L−1 NO gas for 2 h and allowed to ripen at ambient temperature (21±1°C) to evaluate its effects on fruit ripening. NO-fumigation treatments significantly (P ≤ 0.05) suppressed ethylene production and respiration rates during fruit ripening. NO treatments (20 and 40 µL.L−1) retarded fruit softening (hand firmness) and delayed fruit ripening by 2-days as compared to all other treatments. NO-fumigated (40 µL.L−1) ripe fruit exhibited significantly higher pulp cohesiveness, springiness and chewiness as compared to all other treatments. NO fumigation retarded fruit color development (visual colour, L*, a*, b*, C*) and delayed the reduction of h° during fruit ripening. The concentrations of SSC, total sugars, glucose and fructose in the ripe fruit were significantly reduced in response to NO treatments. In conclusion, the postharvest fumigation of NO (20 µL.L−1) suppressed climacteric ethylene production, respiration rate, retarded colour development, softening consequently delayed mango fruit ripening

Yield responses of forage sorghums to salinity and irrigation frequency

Water stress restricts crop yield in both the arid and semi-arid zones of the world. In particular, water stress is associated with low availability of water, as well as osmotic effects associated with salinity. The response of forage sorghum [Sorghum bicolor (L.) Moench] varieties to salinity and irrigation frequency were studied from December 2007 to December 2008. Speedfeed and KFS4 were grown under salinity levels of 0, 5, 10 and 15 dS m-1 and irrigated when the leaf water potential reached -1.0 (control), -1.5 and -2.0 MPa. The irrigation frequency was found to affect growth and yield of the forage sorghums. When irrigation was delayed in leaf water potential of -1.0 to -2.0 MPa, the yield and yield components were found to decrease. The maximum dry forage yields were 45.1, 38.9 and 38.5 g plant-1 for frequent, intermediate and infrequent irrigation regimes, respectively. Increased salinity significantly reduced forage dry yield from 44.09 g plant-1 in the control to 32.76 g plant-1 at salinity of 15 dS m-1. For every one unit increase in salinity, the forage yield decreased by 5.2 units and for every one unit increase in water stress (irrigation frequency), the forage yield decreased by 3.6 units. The variety Speedfeed had higher total dry mass than KFS4 under well-watered conditions but KFS4 performed better than Speedfeed under water stress. For both varieties, infrequent watering reduced dry matter and biomass accumulation, but increased water use efficiency (WUEs) (6.88).Key words: Salinity, irrigation frequency, dry matter, water use efficiency (WUEs), forage sorghum

Stable oxygen and deuterium isotope techniques to identify plant water sources

There is still very little information on the sources of water absorbed by oil palm plant. This information is very important for water management system in oil palm plantation. Thus, this study was carried out to determine current water sources absorbed by the oil palm roots using oxygen (δ18O) and deuterium isotopes (δD) techniques. Sketches of oxygen and deuterium isotope were total rainfall, throughfall, runoff, measurement at 5 soil depths (namely: 20 cm, 50 cm, 100 cm, 150 cm, and 200 cm), and oil palm stem. Results of this study showed huge variance in the values of oxygen and deuterium isotope. Based on Least Significant Difference (LSD) test, there was no significant value in the oxygen and deuterium isotope of stem water and others; however, a similar value was obtained at the depths of 0 - 20 cm and 20 - 50 cm with the stem water. This indicated that oil palm absorbed water from 0 - 50 cm depth. This result agreed with the oil palm rooting system, which has verified that the root quarter is the most active root of oil palm

Changes in water table depth in an oil palm plantation and its surrounding regions in Sumatra, Indonesia

This study was carried out to determine changes in depths of water table in an oil palm plantation and its surrounding region. Daily water table depths and daily climatic elements were considered in this study. Eight well point locations were chosen randomly throughout the oil palm plantation. To test relationships among the different variables, correlation coefficients were statistically tested using t-test at 95 and 99% confidence levels. The results showed that fluctuation depth of the water table at the oil palm area depended on climatic elements. In general, water table depth decreases during dry season and increases during wet season. However, water table depths reduction does not happen permanently. Similarly, water table depths were not changed by oil palm plantation at the oil palm area. Strong correlations were observed between oil palm area and oil palm areas with water table at river side plain. Meanwhile, some other locations were shown to have weak correlation for water table at oil palm and those locations. At oil palm area, water table depth was found to be correlated with some water balance elements such as effective precipitation, soil surface evaporation, run-off and water infiltration rate

Effect of belimbing buluh (Averrhoa bilimbi) juice extract on oxidative stability and microbiological quality of spent chicken meat

This study evaluated the effects of Averrhoa bilimbi juice extract and storage temperature on lipid oxidation and microbial spoilage of spent chicken meat. Ten, 80 weeks old spent chickens were slaughtered, eviscerated and aged for 24 h at 4°C. Thereafter, the Pectoralis major muscles and right thighs were excised and marinated in either A. bilimbi juice extract, pure distilled water, or no marination (control) for either 4 or 9 h at room temperature or 9 or 24 h at 4°C. Lipid oxidation was monitored on the Pectoralis major muscles while the right thighs were assessed for Enterobacteriacea counts. Lipid oxidation was not significantly affected by the type or duration of marination. Marination showed a temperature dependent effect on Enterobacteriacea counts. At room temperature, samples that were marinated by distilled water showed significantly higher Enterobacteriacea counts than the control while those that were marinated with A. bilimbi juice extract showed no growth at both 4 and 9 h of marination. At chilled temperature, marination had no significant effects on the growth of Enterobacteriacea during the 9 or 24 h storage. These results indicated that A. bilimbi juice extract marinade has some antibacterial activities but works better when combined with refrigerated storage

Reliability of graphene as charge storage layer in floating gate flash memory

This study aims to investigate the memory performances of graphene as a charge storage layer in the floating gate with difference doping concentration of n-channel and p-channel substrates using Silvaco ATLAS TCAD Tools. The simulation work has been done to determine the performance of flash memory in terms of memory window, P/E characteristics and data retention and have been validated with the experimental work done by other researchers. From the simulation data, the trend of memory window at low P/E voltage is nearly overlapped between simulation and experimental data. The memory window at ±20V P/E voltage for n-channel and p-channel flash memory cell are 15.4V and 15.6V respectively. The data retention for the n-channel flash memory cell is retained by 75% (from 15.4V to 11.6V) whereas for the p-channel flash memory cell is retained by 80% (from 15.6V to 12.5V) after 10 years of extrapolation with -1/1V gate stress which shows that p-channel flash memory cell demonstrates better data retention compared to n-channel flash memory cell

Decomposition and nutrient release of leguminous plants in coffee agroforestry systems.

Leguminous plants used as green manure are an important nutrient source for coffee plantations, especially for soils with low nutrient levels. Field experiments were conducted in the Zona da Mata of Minas Gerais State, Brazil to evaluate the decomposition and nutrient release rates of four leguminous species used as green manures (Arachis pintoi, Calopogonium mucunoides, Stizolobium aterrimum and Stylosanthes guianensis) in a coffee agroforestry system under two different climate conditions. The initial N contents in plant residues varied from 25.7 to 37.0 g kg-1 and P from 2.4 to 3.0 g kg-1. The lignin/N, lignin/polyphenol and(lignin+polyphenol)/N ratios were low in all residues studied. Mass loss rates were highest in the first 15 days, when 25 % of the residues were decomposed. From 15 to 30 days, the decomposition rate decreased on both farms. On the farm in Pedra Dourada (PD), the decomposition constant k increased in the order C. mucunoides < S. aterrimum < S. guianensis < A. pintoi. On the farm in Araponga (ARA), there was no difference in the decomposition rate among leguminous plants. The N release rates varied from 0.0036 to 0.0096 d-1. Around 32 % of the total N content in the plant material was released in the first 15 days. In ARA, the N concentration in the S. aterrimum residues was always significantly higher than in the other residues. At the end of 360 days, the N released was 78 % in ARA and 89 % in PD of the initial content. Phosphorus was the most rapidly released nutrient (k values from 0.0165 to 0.0394 d-1). Residue decomposition and nutrient release did not correlate with initial residue chemistry and biochemistry, but differences in climatic conditions between the two study sites modified the decomposition rate constants