Diagnosis and Amelioration of Iron Deficiency under Aerobic Rice

ABSTRACT

Iron (Fe) deficiency is one of the serious nutritional disorders in aerobically grown rice on upland alkaline and calcareous soils, which leads to a decline in productivity. With a view to resolve the Fe-deficiency syndrome in aerobic rice, the influence of soil moisture regimes, farmyard manure (FYM) and applied Fe on the release of Fe was assessed under an incubation study. A field experiment was also conducted to evaluate the relative effectiveness of soil and foliar applications of Fe in alleviating Fe deficiency using four rice cultivars (‘IR 36’, ‘IR 64’, ‘IR 71525-19-1-1’ and ‘CT 6510-24-1-2’). Results of incubation study indicated that the application of FYM marginally improved the diethylene triamine pentaacetic acid (DTPA)-Fe status of soil over control. However, application of iron sulfate (FeSO₄ · 7H₂O) at 14 mg Fe/kg with FYM released as much Fe as did the application of 27 mg Fe/kg as FeSO₄ 7H₂O alone. Comparatively higher amounts of Fe were released under water saturation than that under drier soil moisture regimes and the effect of incubation period in releasing Fe was pronounced only under water saturation.

Under field study, supplementation of Fe through integrated or inorganic source caused improvement in the DTPA and ammonium acetate (NH₄OAc) extractable Fe similar to that recorded under incubation. The foliar application of Fe (3% FeSO₄ 7H₂O solution, thrice at 40, 60, and 75 days after sowing of rice, i.e., 45 kg FeSO₄.7H₂O/ha) was most effective and economical in correcting Fe deficiency in aerobic rice, followed by soil application of 150 kg FeSO₄.7H₂O + 10 t FYM/ ha and 305 kg FeSO₄.7H₂O/ha. Among the rice cultivars, ‘CT 6510-24-1-2’ and ‘IR 71525-19-1-1’ performed better under aerobic condition compared to ‘IR 36’ and ‘IR 64’. Differential response of rice cultivars to applied Fe was not related to Fe-nutrition; rather it was apparently related with inherent ability of cultivars to grow under water-stress condition. Ferrous iron (Fe^II) content in rice plants proved to be a better index of Fe-nutrition status compared to total plant Fe and chemically extractable soil Fe. The Fe^II concentration of ≥ 37 mg kg^?1 in plants (on dry weight basis) appeared to be an adequate level at 60 days after sowing for direct seeded rice grown under upland aerobic condition.     

Bt水稻对飞虱和叶蝉及其卵寄生蜂扩散规律的影响

研究了Bt水稻两个纯合品系TT9-3和TT9-4在田间对飞虱、叶蝉及其卵寄生蜂扩散规律的影响.结果表明:在Bt稻区与对照(IR72)区间相互扩散的飞虱有白背飞虱(Sogatella furcifea)、褐飞虱(Nilaparvata lugens);叶蝉有黑尾叶蝉(Nephotetix cincticeps)、白翅叶蝉(Erythroneura subrufa)和电光叶蝉(Deltpcephalus dorsalis);其中以白背飞虱和黑尾叶蝉为主.扩散数量叶蝉多于飞虱;扩散方向以Bt稻区向对照区扩散为主,其中TT9-3与IR72、TT9-4与IR72间白背飞虱与黑尾叶蝉的扩散量差异均达显著水平(P<0.05).在Bt稻区与对照区间相互扩散的飞虱和叶蝉的卵寄生蜂有稻虱缨小蜂(Anagrus spp.)和叶蝉柄翅小蜂(Lynaenon longicrus),数量上后者多于前者,扩散方向也以Bt稻区向对照区扩散为主.     

Producer gas engines in villages of less-developed countries

Producer gas engines could have an important role in the decentralized production of mechanical energy in rural areas of less-developed countries. With this technology mechanical energy is produced from solid fuels by use of internal combustion engines. A comparison with other renewable energy options, on the common basis of energy efficiency and economics, shows that producer gas engines may have significant advantages and deserve serious attention.     

Effects of nitrogen fertilizer treatment and source and season on grain quality of IR64 rice

The effects of nitrogen fertilizer treatment and source (prilled urea, urea supergranule, fresh azolla, rice straw or sesbania or rice straw compost and their combinations) on grain quality were studied in the 1987 crops of variety IR64 at IRRI. Although fertilizer application improved grain yield, it improved protein content only in the case of urea supergranule, azolla and rice straw. Lysine contents of brown rice protein were similar in samples with no N fertilizer and those with the highest protein content in both seasons. Fertilizer treatment regardless of source tended to decrease weight and increase translucency of brown rice in both seasons. Effects on other grain properties were not consistent in both seasons. Season affected more grain properties than fertilizer treatment did, particularly translucency which was higher in the dry season than in the wet season.     

Geochemistry of Tungsten and Arsenic in Aquifer Systems: A Comparative Study of Groundwaters from West Bengal, India, and Nevada, USA

The objective of the current study was to estimate the dose in human tissues after inhalation exposure to airborne particulate matter-bound metals at a landfill site. Field measurements have revealed that the 8-h permissible exposure limit set by the Occupational Safety and Health Administration for particulate matter (PM₁₀) was not exceeded for the working personnel at an outdoor weighing facility in the Akrotiri landfill (Chania, Greece). However, PM₁₀ concentrations were exceeding the EU health protection standards (50 μg/m³). Furthermore, dust emanating from landfill operations contains traces of heavy metals due to the nature of materials (e.g., sludge, batteries) which have been deposited over the lifetime of the landfill. In addition, particulate matter-bound metals concentrations at the landfill are enhanced by refuse truck emissions (e.g., exhaust, tire wear dust, brake wear dust, road surface wear dust and resuspension of deposited PM on a road surface) and resuspension from the surface of the composting site. Estimations of particle-bound metals dose in the human body were performed for arsenite (AS^III), lead (Pb) and cadmium (Cd). The Exposure Dose Model (ExDoM) in conjunction with a Physiologically Based PharmacoKinetic (PBPK) model was applied to determine the dose for an adult Caucasian male worker. The ExDoM was used to estimate the human exposure and the deposition, dose, clearance, retention of particulate matter-bound metals in the human respiratory tract and the mass transferred to the gastrointestinal tract and blood. The PBPK model was developed to describe the movement of metals from the blood into the tissues as a blood-flow-limited model. The results showed that after 1 day of exposure to PM_AsIII, the major accumulation occurs in the lung, muscle and liver. In addition, for PM_Pb, the major accumulation occurs in the bone, blood and muscle whereas as regard PM_Cd the major accumulation occurs in the other tissues (the rest of the body), kidney and liver. The results indicate an increased health risk for an adult Caucasian male worker at the landfill site due to exposure to elevated particulate matter concentrations and their associated metallic content.     

EFFECT OF APPLIED LIME AND BORON ON THE AVAILABILITY OF NUTRIENTS IN AN ACID SOIL

Productivity of resources on acid soils occupying one fourth of the total area in India is abysmally low. Lime is applied to such soils with the primary objective of increasing the productivity of crops by enhancing the availability of native and applied plant nutrients. Greenhouse pot experiments and laboratory experiments were conducted to evaluate the effects of lime and boron (B) on the availability of nutrients in soils and their uptake by plants. The application of lime enhanced the available nitrogen (N,), phosphorus (P), calcium (Ca), magnesium (Mg), sulfur (S), and zinc (Zn) content in soils, which was reflected in their uptake by sunflower (Helianthus annus). On the contrary, availability of copper (Cu), iron (Fe), and manganese (Mn) in soil was reduced due to liming. Sunflower responded very well in terms of dry matter yield to B application to the extent of 175% and 188% under 1 and 2 mg kg^?1 applied levels of B, respectively. Dry matter yield of sunflower was reduced to the tune of 29.2 and 42.7% under 2/3 and 1 lime requirement (LR), respectively, over control. Lime application at 1/3 LR with 2 mg kg^?1 of applied B emerged as an optimum combination in acid soils.     

Drought response of rice at different nitrogen levels using line source sprinkler system

Summary In rainfed rice, the nitrogen status of soil and plant is closely related to the moisture regime in the soil. The lower the soil moisture content, the lower the nitrogen use efficiency in the plants.In this study, the yield and growth responses of four rice cultivars to seven irrigation and three nitrogen levels were evaluated using the line source sprinkler system. Visual observations on the degree of drought reaction and measurement of leaf water potential (LWP) were also made.The effect of drought was least on the traditional variety Kinandang Patong and most on the modern variety IR 20. Increasing nitrogen levels from 0 (no nitrogen fertilizer) to 60 and 120 Kg N/ha increased the degree of water stress. This also resulted in decreased LWP especially when the total water applied was minimal. At all levels of nitrogen, Kinandang Patong had significantly higher LWP than IR 20. There was a curvilinear decrease in the number of days to heading and a linear increase in plant height and dry matter production with increase in total water applied.The yield-water-fertilizer relationships of the four cultivars revealed different production surfaces. The early-maturing IR 52 rice gave the highest grain yield at 120 kg N/ha and with maximum water application of 850 mm. Without nitrogen fertilizer application, Kinandang Patong gave the highest predicted yield with 550 mm of water applied. At 120 kg N/ha and 550 mm of water, IR 36 was superior in yield to other rices tested.Results suggest that in areas of uncertain moisture supply, nitrogen application rate should be reduced from that normally used for irrigated rice.     

Genetic engineering of Indica rice in support of sustained production of affordable and high quality food in developing countries

Summary Indica-type rice provides the staple food for two billion people in Third World countries. Several problems involved in the stable and sustained production of high quality food cannot be solved by traditional breeding. Methods have been established for gene transfer to Indica rice breeding lines to study possible contributions from genetic engineering. Experiments are in progress on the development of transgenic resistance towards Yellow Stem Borer, resistance towards Rice Tungro Virus, accumulation of provitamin A in the endosperm, increase of essential amino acids in the endosperm such as lysine, cysteine and methionine and resistance towards fungal pests such as Rice Blast and Sheath Blight. Transgenic clones from Indica rice breeding lines have been recovered from several of the approaches mentioned, some of which have been regenerated to plants.     

A simple method for the determination of trace levels of alkylphenolic compounds in fish tissue using pressurized fluid extraction, solid phase cleanup, and high-performance liquid chromatography fluorescence detection

A simple automated extraction method for the determination of alkylphenolic compounds in fish tissue is reported. Pressurized fluid extraction is used to extract ground fish tissue, and the resulting extract is purified on aminopropyl silica (APS) extraction cartridges. With no further sample preparation, nonylphenol (NP) and its ethoxylates, up to nonylphenol pentaethoxylate, are quantitated using normal phase (APS Hypersil) high-performance liquid chromatography with fluorescence detection. The major advantage of this technique is elimination of the conventional gel permeation cleanup step, a lengthy procedure designed to remove fish lipids. Spiked recoveries with lake trout averaged 85% for the six NP and NP ethoxylates that were investigated. Tissue concentrations of NP and NP ethoxylates determined in fish from various locations of the Great Lakes region ranged from 18 to 2075 ng/g, wet weight.