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11.
Butter  N. S.  Singh  Gurmeet  Dhawan  A. K. 《Phytoparasitica》2003,31(2):200-203
An insect growth regulator (IGR), lufenuron (Match 5EC), was tested for its toxicity toHelicoverpa armigera on cotton. Potency of the IGR against the larval stage of the pest was demonstrated with respect to larval instars; the LC90 values of 1st, 2nd, 3rd, 4th and 5th instar larvae were 5.63, 7.89, 8.03, 11.39 and 14.76 mg a.i.l −1, respectively. However, different larval instars did not differ significantly with respect to LC50 and LC10. IGR-treated larvae had swollen heads and were significantly smaller (1.5–2.3 mm) than the untreated control (2.9 mm). Larval weight was significantly reduced from 190 mg in the control to 50–70 mg in the lufenuron treatment. IGR treatment in the larval stage significantly affected both pupal length and pupal weight. Pupal duration of the test insect was significantly extended by IGR treatment. Pupal deformities, including an inability to shed the last larval skin and formation of larval-pupal intermediates, occurred following treatment. A significant reduction in adult emergence was recorded. In addition, abnormalities in the form of development of cavities in the forewings of adult were evident. A significant decline in fecundity was noted in the studies. http://www.phytoparasitica.org posting Feb. 3, 2003.  相似文献   
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为了解IAA与棉纤维品质形成间的关系及棉铃各部位IAA积累转运特点,本研究分析了棉铃各部分在发育过程中IAA含量的变化特点。通过选择陆地棉标准系TM-1、长纤维种质‘母35’和短纤维种质‘208’3个纤维长度差异较大的陆地棉材料,利用酶联免疫法对浙江杭州、海南三亚两地田间试验的各材料不同发育阶段的棉仁、棉籽壳、棉纤维、棉铃壳进行了IAA含量的测定。结果表明,不同参试材料的棉仁IAA含量存在明显差异,棉籽壳、棉纤维与棉铃壳的IAA含量峰值出现时间晚于棉仁,棉铃各个组织IAA含量具有随棉铃组织从内向外逐渐降低的趋势。研究表明,IAA可能是棉纤维发育的正效应因子,且棉铃发育过程中IAA可能呈初期在棉仁富集、随发育进程沿棉铃组织由内向外运输的规律。  相似文献   
14.
Cotton produces more biomass and economic yield when cluster planting pattern (three plants per hole) than in a traditional planting pattern (one plant per hole), even at similar plant densities, indicating that individual plant growth is promoted by cluster planting. The causal factors for this improved growth induced by cluster planting pattern, the light interception, canopy microclimate and photosynthetic rate of cotton were investigated in an arid region of China. The results indicated that the leaf area index and light interception were higher in cluster planting, and significantly different from those in traditional planting during the middle and late growth stages. Cotton canopy humidity at different growth stages was increased but canopy temperatures were reduced by cluster planting. In the later growth stage of cluster planting, the leaf chlorophyll content was higher and the leaf net photosynthetic rate and canopy photosynthetic rate were significantly increased in comparing with traditional planting pattern. We concluded that differences in canopy light interception and photosynthetic rate were the primary factors responsible for increased biomass production and economic yield in cluster planting compared with the traditional planting of cotton.  相似文献   
15.
棉花早衰是指由于其自身或外部因素,在有效的生育期内,棉株局部或整体过早终止生命活动而影响棉花产量和品质形成的现象。该文综述了棉花早衰的表现及判断指标,分析了引起棉株发生早衰的因素,并提出了预防棉花早衰的对策措施,为今后开展相关工作提供参考。  相似文献   
16.
江苏省是全国产棉大省,在全国占有重要地位.近年来,江苏高品质棉有了很大发展,但也面临一些问题,如品种单一,缺乏有效的产销衔接等.本文提出了江苏高品质棉优势区域发展战略措施.  相似文献   
17.
The application of pesticides is not simply delivering chemicals to the target area. It also involves considering the negative aspects and developing strategies to deal with them during the application process, to ensure the maximization of pesticides use efficiency and the maintenance of the ecosystem. Unmanned aerial vehicle (UAV) sprayers demonstrate unique advantages compared to traditional ground sprayers, particularly in terms of maneuverability and labor intensity reduction, showed great potential for chemical application in pest control. It is undeniable that there exist challenges in the practice of UAV spraying, such as higher potential risks of pesticide drift or pathogen transmission, uncertainty canopy deposition for different crops, and unexpected leaf breakage induced by downwash flow. Maximizing the utilization of downwash flow while avoiding lateral air movement outside the intended target crop area is a major issue for chemical application with UAV sprayers, particularly in light of the increasingly apparent consensus on the need for enhanced environmental protection during the chemical application process. It must be considered that the operation strategy in different scenarios and for different crop targets is not the same, unique requirements should be given on nozzle atomization, flight parameters, adjuvants and aircraft types in specific working situations. In future, the implementation of spray drift prediction, technical procedures development, and other solutions aimed at reducing pesticide drift and improving deposition quality, is expected to promote the adoption of UAV sprayers by more farmers. © 2023 Society of Chemical Industry.  相似文献   
18.
棉花黄萎病菌毒素ELISA检测方法的建立及其应用   总被引:6,自引:1,他引:6  
以纯化的棉花黄萎病菌毒素(PLPC)免疫新西兰白兔制备了PLPC特异性抗血清,建立了可特异性检测棉花黄萎病菌毒素的A蛋白双抗体夹心ELISA方法。应用建立的ELISA方法测定了病菌培养滤液、人工接种幼苗和大田病株不同组织中的毒素,结果表明:不同产毒能力菌株(VD 8和VD-5)在25℃下振荡培养3d后就能在培养滤液中检测到毒素,这比生物测定要早2~3d。将VD-8菌株的孢子以灌根方式接种泗棉3号幼苗5d后,就能从接种幼苗的茎杆和叶柄中检测到毒素,这比幼苗自然发病显症要早3~5d。在测定的30份大田病株茎杆、叶柄、叶脉样品中,阳性样品率为100%。这些结果表明建立的ELISA方法可用于菌株产毒能力的测定和大田棉花黄萎病的早期诊断。  相似文献   
19.
利用山农棕02、丰抗6号、中棉45 3个品种在大田栽培的条件下,研究了叶片和纤维中蔗糖磷酸合成酶活性的变化及与糖含量的关系。结果表明,在3个品种的叶片和纤维中,蔗糖磷酸合成酶活性均出现双峰,在开花当天最高,花后18d次之,整体呈下降趋势;与此同时可溶性总糖和蔗糖的含量变化以及光合速率的变化也成相似的变化。3个品种中,丰抗6号蔗糖磷酸合成酶活性和含糖量最高,中棉45次之,山农棕02最低。3个品种的相应观测指标之间均呈极显著差异。  相似文献   
20.
爱比菌素对朱砂叶螨的室内毒力及生物学影响   总被引:2,自引:0,他引:2  
爱比菌素是一种新的生物杀螨剂,是由除虫链霉菌发酵产生的大环内酯化合物。它对久效磷抗性敏感的两组朱砂叶螨种群有很高的毒性,LC50值各为0.0038mg/L和0.0153mg/L,LC95值分别为0.0263mg/L和0.0279mg/L。用0.0288mg/L(近似LC95)的浓度处理带螨的棉叶,幼若螨在72h死亡率达90%,对卵无效;该浓度处理棉苗7天后对成螨和幼若螨无残效。用近似LC50浓度(  相似文献   
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