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在棉花苗期施用多效唑对棉花生长发育、棉花产量和纤维品质有明显的影响。在300ppm以内,施用多效唑能在一定程度上抑制棉苗的生长,但可在中、后期促进棉株的发育,使棉株提早现蕾,进而提高棉花产量,改善纤维品质。在施用技术上,用多效唑浸种和在不同苗龄期喷施应使用不同的浓度。 相似文献
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由四川省化工研究设计院新合成的杀虫剂８９─１，对棉铃虫（末龄幼虫）的ＬＣ_（５０）为２３０±５．５ｐｐ，乐果乳油为６２５±６．４ｐｐｍ，８９─１的毒力高于乐果１．７倍。田间防治试验表明，３０％８９─１乳油７５０－防治棉铃虫效果令人满意，施药３天以后防效为８０％以上，１０天后防效为８６．４％，与当前防治铃虫的优秀农药２５％喹硫磷１０００×防效相当，大大优于４０％乐果乳油７５０×的防效。 相似文献
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《African Journal of Range and Forage Science》2013,30(1-3):46-51
The effects of fire, bruchid seed beetles and soil type on the germination and seedling establishment of Acacia drepanolobium were experimentally investigated. Seeds subjected to three seed treatments (bruchid damaged, bruchid-free burnt, and bruchid-free unburned) were germinated in three different soil types (black cotton, red sandy, and clay loam soils). Undamaged seeds had significantly higher germination (85.3%) than either beetle damaged (20.6%), or burnt seeds (3.4%). Soil type did not influence germination or seedling survival. Burnt seeds had an average germination of 2% in clay loams and 5.4% in red sandy soils, while beetle damaged seeds had an average germination of 15.6% in clay loams and 28.7% in black cotton soils. Treatment effects on seedling mortality or survival were not significant but seedlings from undamaged seeds had higher survival rates than those damaged by bruchid beetles. 相似文献
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COTTON2K在新疆棉花精准种植管理中的应用 总被引：1，自引：0，他引：1
简述了棉花模拟模型COTTON2K的新增特点,并利用新疆2002~2003年棉花数据对该模型进行校正和验证,指出模型验证中存在的问题。 相似文献
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杂种棉花叶片气孔形态及数量的扫描电镜观察 总被引：6，自引：0，他引：6
用扫描电镜观察杂种棉花叶片的气孔分布及形态表明：扫描电镜观察气孔的形态更形象、更直观、更可靠。用所测数据看出，杂种棉的孔在形态大小与新本棉无甚差异，但杂种棉在单位面积的气孔数则比亲本棉有明显增多的趋势。这一现象为杂种优势的表现提供了一定的形态学依据。 相似文献
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Estimation of irrigation requirement for sustainable water resources reallocation in North China 总被引：4，自引：0，他引：4
The South-North Water Transfer (SNWT) project (upon completion) will deliver some 4.8 billion m3 of water per annum to Hebei, Beijing and Tianjin — greatly mitigating water shortage in North China. Surface water that is currently restricted to urban use could then become partly available for agricultural production. This will reduce the dependence of agriculture on groundwater, which will in turn retard groundwater depletion in the region. This study determines the spatial and temporal distributions of agricultural water requirement in Hebei Plain. This in turn lays the basis for surface water reallocation following the completion of the SNWT project. DSSAT and COTTON2K crop models are used along with crop coefficient methods to estimate required irrigation amounts for wheat, maize, cotton, vegetables and fruit trees in Hebei Plain. The study uses 20 years (1986-2006) of agronomic, hydrologic and climate data collected from 43 well-distributed stations across the plain. Based on the results, wheat accounts for over 40% of total irrigation water requirement in the plain. Similarly, wheat, maize and cotton together account for 64% of the total irrigation water requirement. The piedmont regions of Mount Taihang have the highest irrigation requirement due to high percent farm and irrigated land area. The months of April and May have the highest irrigation water requirement, respectively accounting for 18.1% and 25.4% of average annual irrigation. Spatial and temporal variations in our estimated irrigation water requirement are higher than those in the officially published statistics data. The higher variations in our results are more reflective of field conditions (e.g. precipitation, cropping pattern, irrigated land area, etc.). This therefore indicates a substantive improvement (in our study) over the average statistical data. Based on our simulation results, viable surface water reallocation strategies following the completion of the SNWT project are advanced and discussed. 相似文献
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Simulation of the effect of pruning and topping on cotton growth using COTTON2K model 总被引：1，自引：0，他引：1
COTTON2K, like most other cotton production models, does not always adequately represent local growth conditions owing to the fact that it fails to take into account some indigenous cultivation practices. For instance, pruning and topping, a common practice for cotton cultivation in China is not included in the model simulation of COTTON2K. The objective of this research therefore was to: (1) modify COTTON2K source code and slot pruning and topping simulation switch on to the model, and (2) calibrate and validate the modified COTTON2K model with field data from pruning and topping cultivation practice. First, field collected data in 2003 and 2004 were compared between the treatments, with and without pruning and topping, and the COTTON2K source code updated with the ‘pruning and topping’ switch. This was followed by the calibration and validation of the updated model with field data and simulation of the effect of pruning and topping on cotton performance. It was noted from field observations that pruning and topping reduced total fruit sites, but at the same time, increased retained boll number, possibly due to significant reductions in abscised fruit sites. Though total dry matter production dropped, more dry matter allocation to reproductive organs, however, enhanced higher cotton lint yield in the pruning and topping treatment. Results of the modified model simulation showed that growth in the number of main-stem node ceased after topping. Furthermore, there was more biomass allocation to reproductive organs, such as green and open bolls under pruning and topping. Coefficient of determination above 0.8 for most of the growth factors was obtained in the calibration and validation processes under pruning and topping, a strong indication of the level of success of the model modification. 相似文献
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天然彩色棉叶片光合色素测定分析 总被引：5，自引：0，他引：5
对彩色棉花叶片不同生育时期的光合色素含量进行了较为系统的测定分析 ,表明彩色棉叶片叶绿素a、b、(a+b)含量的动态变化趋势与白色棉较为一致 ,但彩色棉叶片的叶绿素a、b、(a +b)含量除幼苗期外 ,各生育时期 (特别是后期 )均比白色棉低。彩色棉中 ,棕色棉与绿色棉之间的叶绿素a、b、(a +b)含量也有差异。 相似文献
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棉花原生质体培养研究进展（综述） 总被引：1，自引：0，他引：1
张宝红 《四川农业大学学报》1995,13(1):55-61
本文在介绍棉花原生质体培养研究历史的基础上，综述了棉花原生质体分离、培养及植株再生中的一系列问题，并介绍了棉花原生质体培养在遗传改良中的应用。 相似文献
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