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1.
河南农业大学烟草育种课程组全体教师对《烟草育种学》的教学内容、教学方式和考核形式进行了系列改革。近年来的教学实践表明,这些改革措施充分调动了学生学习的主动性,达到了改善教学质量的效果,为高等农业院校该课程的教学提供一定的参考。 相似文献
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河川基流分割法在山丘区地下水资源量评价中的运用 总被引：1，自引：0，他引：1
山丘区河川基流分割方法很多，采用不同方法的分割成果不尽相同。在地下水资源评价中，根据云南省自然地理独特，气候复杂多样，降水量丰沛，洪水频繁，河川径流过程线普遍呈连续多峰型的特性，寻求一种既能满足水资源综合规划要求，又符合云南实际分割河川基流量的方法，是地下水资源评价中的重要内容。采用适宜水均衡法和直线斜割法的径流资料分割河川基流量，求出两种方法之间的换算系数，修正水均衡法的分割成果，一是达到了以直线斜割法统一分割河川基流量的目的；二是提高了山丘区地下水资源量评价的精度，为探索山丘区地下水资源量及时空分布规律提供技术支撑。 相似文献
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The study aiming to determine the effect of different irrigation regimes and water stress imposed at different growth stages on water use and leaf yield of flue‐cured tobacco plant (Nicotiana tabacum L.), was carried out during the period of 2000–03. The field trials were conducted on a silty loam Entisol soil, poor in organic matter and rich in potassium on the fields of the Atatürk Soil and Water Resources Research Institute in Kırklareli. A randomised complete block design with three replications was applied and K‐326 Virginia tobacco cultivar was used in the experiment. Three known stages of the plant, vegetative (V), yield formation (F) and ripening (R), were considered and a total of 14 (including rain‐fed) irrigation treatments were applied. All the experimental treatments were irrigated on the same day in each growth stage with the amount of water required to fill the 0–90 cm soil depth to field capacity, and three levels of water amount reductions (0, 40 and 60%) were applied at each development stage. A single irrigation was applied during the second part of the vegetative stage, while subsequent water applications were at the 50 and 70% depletion level during the yield formation and ripening stages, respectively. Results of the 3‐year study show that either total irrigation water amounts and number of applications, or leaf yields are closely related to precipitation rate and distribution during the growing year. While the seasonal irrigation amounts applied in the adequate irrigation treatment (VFR) were greater (945 and 815 mm respectively in the drier experimental years of 2000 and 2001), they were much lower (587 mm) during the rainy year of 2003. The highest leaf yields in the range of 5170–6050 kg ha−1 were obtained from the fully irrigated programme (VFR), from treatments with 40% reduction in irrigation water amount at any stage (V1FR; VF1R, VFR1) and irrigation programme (FR) including omitted irrigation at vegetative stage and fully irrigated during the next two stages. It was also determined that close linear relationships exist between seasonal evapotranspiration rate and leaf yield, and seasonal evapotranspiration deficit and relative yield reduction, during each of the experimental years. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Sogatella furcifera (Horváth) (Hemiptera: Delphacidae) is the most serious pest on rice in southwestern China. Yunnan province is within this region and is a major overwintering area for S. furcifera in China. This field study was carried out over 4 yr (2010–2013) and focused on S. furcifera distribution, population density, and demography, as well as the relationship between various environmental factors and the distribution and density of overwintering S. furcifera in Yunnan. Our study demonstrated that overwintering populations of S. furcifera mainly occurred in valleys and lowlands below 25.02°N and 1,680 m above sea level (a.s.l.), where ratooning rice was present. The overwintering range of S. furcifera has expanded in Yunnan compared with 20 yr ago, and regional climate change is believed to be the main contributing cause for this expansion. Environmental factor analysis showed that the mean air temperature of the coldest quarter and precipitation of the coldest quarter were two key factors that were strongly linked to the overwintering distribution and density of S. furcifera in Yunnan. Wintertime temperature was the principal influencing factor to determine the distribution and density of S. furcifera, while the effect of precipitation was indirect in that it influenced the insect’s distribution via its host. This study documented the major overwintering areas of S. furcifera in Yunnan, which can be used to predict outbreak potential in the following spring. Hence, key climatic factors, overwintering distribution, and density of S. furcifera should be used when forecasting outbreaks in spring. 相似文献
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Xiao‐Ming Zhang Gabor L Lvei Marco Ferrante Nian‐Wan Yang Fang‐Hao Wan 《Pest management science》2020,76(1):366-374