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991.
《Plant Production Science》2013,16(3):288-297
Abstract

Cultivation of the oil palm (Elaeis guineensis Jacq.) has expanded tremendously in recent years such that it is now second only to soybean as a major source of the world supply of oils and fats. Presently, Southeast Asia is the dominant region of production with Malaysia being the leading producer and exporter of palm oil. This paper reviews the various factors that have led to oil palm occupying its present position, including biological, technical, managerial, environmental, and socio-political aspects. Biological features recognised as critical to the high productivity of the crop are examined. These include its perennial and evergreen nature (giving a continuous year-round canopy cover intercepting a high proportion of incoming radiation), the year-round production of fruit bunches and the high partition of total assimilates into harvested product. Scientific and managerial aspects contributing to the success of the crop include the significant genetic improvements and production of high quality planting materials, the development and application of finely-tuned agronomic practices, the appropriate scale and efficient organisation of oil palm plantations and the continuous R&D and good infra-structural support provided in the main producing countries. The programmes of crop improvement through the utilisation of traditional breeding and selection methods, the development and benefits of vegetative propagation techniques using tissue culture and ongoing efforts to apply molecular and genetic engineering techniques to improve and modify oil composition, are reviewed. Finally, the nutritional qualities of palm oil as a healthy component of diet are briefly described.  相似文献   
992.
Summary

Cultivars can be selected for traits that improve water use efficiency, and fertilizers and other nutrient sources also can be managed to optimize water use efficiency of a crop. Both cultivar selection and nutrient management impact water use efficiency by altering photosynthetic rate, yield, rooting characteristics, transpiration, or soil evaporation. In order to optimize water use efficiency, cultivar and nutrient decisions should be made jointly. This integrated approach will lead to improvements in water use efficiency, with an increase in productivity and profitability per unit water.  相似文献   
993.
通过对大田春玉米进行不同生育期灌水和施氮处理,研究了不同灌水和施氮对玉米农田硝态氮运移和产量的影响。结果表明:生物产量和籽粒产量及其灌溉水利用效率有随施氮量增加而增大的趋势。与全生育期灌水比较,任何生育期不灌水处理都造成生物产量和籽粒产量降低,而生育期不灌水处理增加了灌溉水利用效率,两个生育期不灌水处理的生物产量和籽粒产量的灌溉水利用效率最高。在春玉米生长阶段,拔节期,抽穗期和成熟期不灌水对生物产量影响显著,抽穗期不灌水、苗期与灌浆期不灌水、拔节期期和灌浆期不灌水处理显著影响籽粒产量。  相似文献   
994.
Improved planting methods and foliar application of glycinebetaine (GB) and salicylic acid (SA) can improve the water productivity in field crops under limited water supply conditions. A 2‐year field study was conducted to evaluate the possible role of different planting methods and foliar applications of GB and SA in improving the yield, quality and water productivity of hybrid sunflower (Helianthus annuus L.). The crop was planted by flat sowing (75 cm spaced rows) and ridge sowing (75 cm spaced ridges), with GB and SA applied exogenously at 100 and 0.724 mm , respectively, at both budding and flowering stages, while control plots received distilled water. Ridge sowing, rather than flat sowing, improved the biological yield, oil yield, leaf area index (LAI), crop growth rate (CGR), plant height, water‐use efficiency and final achene yield during both the years. Foliar applications of GB and SA at both the stages improved the achene yield, although foliar application of GB at flowering was the most effective. Neither the planting methods nor the foliar application of GB and SA altered the achene oil contents during both the years. Foliar application of GB and SA increased the free proline content of the leaf and GB contents at flowering but reduced the achene protein contents, whereas planting method had no effect on these attributes across the years. Of the foliar applied chemicals, GB was more effective in improving sunflower growth and yield and water productivity than SA. To conclude, ridge sowing coupled with foliar application of GB at flowering stage could be beneficial for achieving maximum yields of hybrid sunflower under relatively water limited conditions in the field.  相似文献   
995.
不同颜色防虫网覆盖栽培对豇豆生长发育的影响   总被引:1,自引:0,他引:1  
研究了不同颜色(白色、黑色、红色、蓝色、绿色、银灰色)防虫网覆盖对栽培豇豆生长发育的影响。从豇豆的生育期、株高、茎粗、叶面积及叶绿素含量指数、产量和病虫害等方面综合考虑,在三亚地区绿色防虫网是较适合豇豆栽培的覆盖材料。  相似文献   
996.
以大田棉花为对照(CK),研究了环塔里木盆地杏、棉间作系统对棉花的产量和纤维品质特性的影响.结果表明:杏、棉间作下棉花的产量及其构成因素相比对照均有不同程度的减小,且随着距杏树垂直距离的增加,其变化呈偏态分布趋势;在杏、棉间作区,棉花的比强度、伸长率和马克隆值明显减少,而纤维长度、整齐度、黄度和纺纱指数则形成了明显的增...  相似文献   
997.
Panax ginseng C.A. Meyer, commonly known as ginseng, is a perennial herb. Agricultural practices have an influence on growth and yield of P. ginseng plants. Effect of thinning flower buds (treatment A (TA) the outermost whorl of flower buds in the umbels was retained while all other buds were excised; treatment B (TB) the two outer whorls of flower buds in the umbels) on fruit traits, which include number of fruits per plant, single fruit: double fruit ratio, fruit weigh (FW) per square meter, weight of 100 fruits, vertical length of fruit (VLF), horizontal diameter of the fruit (HFD) and thickness of the fruit (TF), seed traits, which include number of seeds per square meter, weight of 1000 seeds, number of different seed grading categories (extremely large seeds (ELS), large seeds (LS), medium-sized seeds (MS), small seeds (SS)) per square meter, vertical length of the seed (VLS), horizontal diameter of the seed (HSD), thickness of the seed (TS), and the root yield and total ginsenosides content of root of four- and five-year-old cultivated P. ginseng was studied in Fusong region of north-eastern China. The results showed that the FW and VLF, the weight of 1000 seeds, number of ELS per square meter, VLS and HDS of ELS, HDS and TS of MS and root yield were increased significantly by TA and TB (p < 0.05), whereas the number of MS and SS were significantly reduced (p < 0.05) in four- and five-year-old plants. The number of ELS and LS in TB and control were higher than that of in TA, and not significant was observed between TB and control. The root yield in TB was significantly higher than that in control of five-year-old plants. Number of the seeds per square meter of five-year-old plants was higher than that of four-year-old plants. The results indicated that the method of thinning flower buds, which was the two outer whorls of flower buds in the umbels, on five-year-old cultivated P. ginseng plants was a favourable method to promote the production of high-quality seeds and maximise the root yield.  相似文献   
998.
沙地衬膜水稻品种筛选试验研究   总被引:1,自引:0,他引:1  
为筛选适合科尔沁沙地衬膜种植的优良水稻品种,特选取吉特639等8个品种进行对比试验研究,结果表明,吉特639表现最优,产量高达526.7 kg/667 m2。其次是稻花香2号、吉粳88,平均产量分别为505.7 kg/667 m2和504.1 kg/667 m2。而且米质好、口味佳,均可作为沙地衬膜水稻品种进行大面积推广种植。  相似文献   
999.
探讨了不同生长年限对青海草地早熟禾人工草地生长特性和种子产量及构成因子的影响,为青海草地早熟禾种子生产提供理论依据。结果发现,随着人工草地生长年限的延长,生殖枝高度、营养枝高度以及花序长度总体上都呈降低的趋势。不同的生长年限对青海草地早熟禾种子产量及其构成因子的影响表现在:2龄人工草地的种子产量最高,达到496.96k...  相似文献   
1000.
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