The Experts below are selected from a list of 40488 Experts worldwide ranked by ideXlab platform
Hiroyuki Shimono - One of the best experts on this subject based on the ideXlab platform.
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rice genotypes that respond strongly to elevated co2 also respond strongly to low Planting Density
Agriculture Ecosystems & Environment, 2011Co-Authors: Hiroyuki ShimonoAbstract:Abstract Screening for cultivars that respond strongly to elevated atmospheric CO2 concentration ([CO2]) is essential for increasing the productivity of C3 crops in the future high-[CO2] world. However, the cost of research facilities capable of increasing [CO2], such as free air-CO2 enrichment (FACE) rings, limits the number of accessions that can be tested. Since low Planting Density and elevated [CO2] can both increase individual crop growth, I therefore hypothesized that cultivars capable of responding strongly to high [CO2] would also respond strongly to low Planting Density. To test this hypothesis, I grew four rice cultivars, previously determined to respond differently to elevated [CO2] in a 2-year FACE experiment, under normal and half-normal Planting densities in a paddy field. The plant biomass was significantly increased (by 36–64%) by low Planting Density, with a significant cultivar × Density interaction. Panicle number and grain weight showed similar responses. The change in grain weight caused by low Planting Density was closely, significantly (P
Nicolas Marron - One of the best experts on this subject based on the ideXlab platform.
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Planting Density affects growth and water use efficiency depending on site in populus deltoides p nigra
Forest Ecology and Management, 2013Co-Authors: Julien Toillon, Regis Fichot, Erwin Dalle, Alain Berthelot, Franck Brignolas, Nicolas MarronAbstract:Abstract Poplar coppice plantations for biomass production can be conducted under either short rotation coppice (SRC) or short rotation forestry (SRF) systems, depending on Planting Density and rotation length. It is likely that differences in Planting Density affect tree physiology through competition for resource acquisition, including light, water and nutrients. In this paper, we hypothesized that the effects of Planting Density on growth and water-use efficiency (assessed through bulk leaf carbon isotope discrimination, Δ 13 C) in poplar depend on site characteristics in terms of soil fertility and water availability. To test this hypothesis, 56 Populus deltoides × P. nigra genotypes were planted under both SRC and SRF and replicated at two sites differing for pedoclimatic conditions. At the most favorable site for growth, trees grown at the higher Density (SRC) displayed higher stem height, lower stem circumference, higher specific leaf area, higher mass-based leaf nitrogen contents and higher Δ 13 C, indicating that increased tree Density mainly accentuated competition for light. Under less favorable conditions, trees grown under SRC still displayed lower stem circumference, higher specific leaf area and higher mass-based leaf nitrogen contents. However, stem height remained unaffected by increasing Planting Density while Δ 13 C was lower, likely because of increased competition for water availability. Genotypic rankings across Planting densities were overall conserved while they were significantly modified across sites, suggesting that rankings for genotypic performances were much less affected by Planting Density than by site. Realized growth measured after 2 years (height and circumference) was weakly correlated with Δ 13 C, but a negative relationship between Δ 13 C and growing season leaf increment rate was observed in most cases. The absence of trade-off between growth and water-use efficiency combined with the large genotypic variations observed for these traits confirms the potential for selecting genotypes with high water-use efficiency without counter-selecting on biomass production in P. deltoides × P. nigra .
Hu Ying - One of the best experts on this subject based on the ideXlab platform.
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Planting Density Test of New Soybean Variety Zhonghuang 30
Journal of Hebei Agricultural Sciences, 2020Co-Authors: Hu YingAbstract:In order to explore the best Planting Density of new soybean variety Zhonghuang 30 in Chengde area,using the regression design method,with 6 Planting densities of 18.0 × 104,22.5 × 104,27.0 × 104,33.8 × 104,36.0 ×104 and 45.0 × 104 plants/hm2,the yield,plant diseases and insect pests of soybean under different Planting densities were analyzed and the regression equation between Density and yield of soybean was generated.The results showed that in the experimental Density range,with the increasing of Planting Density,the feed rate,brown spot rate and purple spot rate were decreased first and then increased,the occurrence rate of 3 kinds of diseases and insect pests were the lowest under the Planting Density of 22.5 × 104 plants/hm2.The yield of soybean was increased first and then decreased,the quadratic regression equation between Density and yield of soybean was Y =-2 731.425 9 + 358.902 2X-5.033 5X2.In the test conditions the yield was highest(3 801.667 kg/hm2) under the Planting Density of 33.8 × 104 plants/hm2.
Huang Yu-feng - One of the best experts on this subject based on the ideXlab platform.
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A Test on Planting Density of Soybean Variety "Zhonghuang 30"
Ningxia Journal of Agriculture and Forestry Science and Technology, 2020Co-Authors: Huang Yu-fengAbstract:A test was made on different Planting densities of "Zhonghuang 30" which had be approved by State as a soybean variety.The result shows that the highest yield,4821.15 kg/hm2,was got with the Planting Density of 270 thousand plants/hm2 and the rank of the other treatments in Density are 250 thousand plants/hm2,240 thousand plants/hm2,210 thousand plants/hm2,285 thousand plants/hm2 and 225 thousand plants/hm2 according to the level of the yields from high to low.It can be seen that with increase of the Planting densities the yields were increasing gradually and reached the peak at the Density of 270 thousand plants/hm2 and then decreasing gradually with further increase of the Planting densities.
Jianbo Shen - One of the best experts on this subject based on the ideXlab platform.
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root competition resulting from spatial variation in nutrient distribution elicits decreasing maize yield at high Planting Density
Plant and Soil, 2019Co-Authors: Hongbo Li, Xin Wang, Rob W Brooker, Zed Rengel, Fusuo Zhang, W J Davies, Jianbo ShenAbstract:Nutrient spatial heterogeneity occurs ubiquitously in soil, but its impact on plant growth and competition throughout the whole growth cycle remains unclear. We assessed the effects of different nutrient supply patterns and Planting Density on maize (Zea mays L.) growth rate, root competitive intensity and grain yield. Maize was grown with homogeneous or heterogeneous nutrient (ammonium and phosphorus) supplies under low and high Planting densities in field conditions. Nutrient patches promoted root proliferation and plant growth rate in the short term; however, with nutrient depletion and roots still proliferating in the patch zone, the plant growth rate was surpassed by that of plants in the homogeneous ammonium and phosphorus treatments with time. Consequently, final shoot biomass showed no difference between nutrient supply patterns at a given Planting Density. Furthermore, the temporal decoupling between root growth and soil nutrient availability induced greater competitive intensity in the heterogeneous than homogeneous treatments between the vegetative stage and anthesis. Under these conditions, heterogeneous ammonium and phosphorus supply markedly decreased grain yield at high Planting Density. Our results demonstrate that heterogeneous nutrient supply-induced root competition at high Planting Density modulates the dynamics of plant development and decreases final productivity.
