Electrical Properties of Spherical Ag-Pd Alloy Particles Synthesized by Ultrasonic Spray Pyrolysis

Spherical Ag-Pd alloy particles were prepared from an aqueous solutions of AgN0_3 and Pd (N0_3) 2 by ultrasonic spray pyrolysis. As-prepared powders were dense and non-agglomerated particles, and had sub-micron size and narrow size distribution. XRD sbows that as-prepared particles are polycrystalline and that the crystal phase of the as-prepared particles has an alloy composition. Ag-Pd alloy particles obtained from spray pyrolysis offer superior oxidation-resistivity of Pd and specific resistivity as compared with those obtained from coprecipitation

Effects of Soil Moisture Conditions before Heading on Growth of Wheat Plants under Drought Conditions in the Ripening Stage: Insufficient Soil Moisture Conditions before Heading Render Wheat Plants More Resistant to Drought during Ripening

Plants growing on soil with insufficient moisture need deep and dense roots to avoid water stress. In crop plants, the production of dry matter during ripening of grains is critically important for grain yield. We postulated that shoot growth would be suppressed but root growth would continue under an insufficient soil moisture condition before heading, while shoot growth would be more vigorous than root growth under a sufficient soil moisture condition. We anticipated that the plants growing under an insufficient soil moisture condition before heading would produce more dry matter and grain under an insufficient soil moisture condition during ripening. In order to examine our hypotheses and to determine the fundamental conditions for improving grain yield and efficient use of irrigated water under limited irrigation, we grew wheat plants (Triticum aestivum L., cv. Ayahikari) in pots (30 cm in diameter, 150 cm in height) with insufficient soil moisture (PD-D pots) or sufficient soil moisture (PW-D pots) for six weeks before heading followed by full irrigation, and then insufficient soil moisture condition during ripening. The growth of shoots was suppressed significantly but that of roots was not before heading in PD-D plants, with a higher resultant ratio of root to shoot than in PW-D plants. The former retained a high leaf water potential and, therefore, were able to produce more dry matter and grain during soil moisture depletion during ripening as compared with the latter plants. We also obtained similar results with field-grown plants

Performance of a High-Yielding Modern Rice Cultivar Takanari and Several Old and New Cultivars Grown with and without Chemical Fertilizer in a Submerged Paddy Field

A high nitrogen-uptake capacity and effective use of absorbed nitrogen for dry matter and grain production are required to improve the production cost and environmental pollution. We characterized grain yield, dry matter production and nitrogen accumulation in six rice cultivars: Sekitori (released in 1848) and Aikoku (1882), referred to as SA cultivars hereafter; Koshihikari (1956); Nipponbare (1963) and Asanohikari (1987), referred to as NA cultivars hereafter; and Takanari (in 1990) as a high-yielding modern cultivar. The plants were grown with and without chemical fertilizer in a submerged paddy field. When plants were supplied with manure and chemical fertilizer, Takanari consistently produced the heaviest grain and dry matter, followed by the NA cultivars, and the SA cultivars the lightest. Dry matter production before heading was greater in Takanari and the NA cultivars due to the longer duration of vegetative growth. Dry matter production after heading was greatest in Takanari, with a larger crop growth rate (CGR), and smallest in the SA cultivars with a shorter ripening time. Greater dry matter production during ripening was accompanied by the greater accumulation of nitrogen by Takanari and NA cultivars. These plants developed a larger amount of roots. The smaller light extinction coefficient of the canopy was also attributed to the higher CGR in Takanari. When plants were grown without chemical fertilizer, Takanari also produced heavier grain and dry matter, followed by the NA cultivars. The heavier grain in these cultivars resulted from the greater dry matter production before heading, which was due to the longer period of vegetative growth. The greater dry matter production and nitrogen accumulation by Takanari and NA cultivars were evident when plants were grown with chemical fertilizer. Koshihikari was characterized by a higher CGR and greater nitrogen accumulation during ripening in the absence of chemical fertilizer which should be noted in efforts to decrease rates of nitrogen application

Effects of Planting Pattern on the Interception of Solar Radiation by the Canopy and the Light Extinction Coefficient of the Canopy in Rice Plants Direct-sown in a Submerged Paddy Field

In order to investigate effects of planting pattern on the interception of solar radiation by the canopy and the light extinction coefficient of the canopy in rice, the rice plants direct-sown in a submerged paddy field were grown in six planting patterns (A through F). In plots A, B and C, the planting density was 20.7 hills m-2 (22 cm × 22 cm spacing) with five, three and one plant per hill, respectively, and in plots D, E and F, the planting density was 82.6 hills m-2 (11 cm × 11 cm spacing), 44.4 hills m-2 (15 cm × 15 cm spacing), and 44.4 hills m-2 (7.5 cm × 30 cm spacing), respectively, with one plant per hill. At the tillering stage, the greater the tiller number and leaf area index, the larger the interception of solar radiation by the canopy. The tiller number was larger in the plots with one plant per hill, higher plant density and square arrangement of hills. At the early ripening stage, the light extinction coefficient of the canopy was smaller in such plots. The larger the average inclination of leaf blades, the smaller the light extinction coefficient of the canopy. The difference in stem inclination in the canopy might be responsible for the difference in the inclination of leaf blades. In the plots with one plant per hill, higher plant density and square arrangement of hills, stems were more erect. Within the range of planting patterns in our study, both the rate of interception of solar radiation by the canopy and the light-intercepting characteristics were significantly more favorable in the plots with one plant per hill, higher density and a square arrangement of hills

Biomass Production and Lodging Resistance in ‘Leaf Star’, a New Long-Culm Rice Forage Cultivar

Biomass production and lodging resistance in the new long-culm forage cultivar ‘Leaf Star’, developed using a precise evaluation method for lodging resistance, were evaluated by comparing these properties with those of its parents and recently improved forage rice cultivars. Leaf Star had a higher biomass production of above-ground parts than its parents, and its straw yield was 13 t ha-1. The bending moment of the basal internode at breaking in Leaf Star was three times higher than that in Koshihikari, owing to a large section modulus and a high bending stress. Biomass production of above-ground parts of Leaf Star did not differ significantly from that of other forage cultivars. However, Leaf Star had the highest straw yield of all forage cultivars. Leaf Star accumulated a large amount of starch in straw. Bending moment of the basal internode was the highest among forage cultivars owing to a large section modulus. These results show that the traits related to lodging resistance such as culm thickness and culm stiffness could be introduced into long-culm cultivars by using the precise evaluation method for the traits related to lodging resistance. The results also show that Leaf Star has a large biomass and high quality, which are suitable properties for feed and biofuel production