Use of netting and whitewash spray to protect papaya plants against Nivun Haamir (NH)-dieback disease     

A. Franck  M. Bar-Joseph 《Crop Protection》1992,11(6):525-528

A disease causing the decline of papaya (Carica papaya) plants was noticed in the Jordan Valley in 1982. The disease caused severe yellowing of the upper leaves and dieback of the apex. The disease was not transmissible mechanically and continued efforts to associate viruses and viroids have so far been unsuccessful. Epidemiological observations suggested that the disease is airborne and probably caused by a mollicute. In order to test this hypothesis, plots were covered by an insect-proof net and with white nets providing 15, 30 and 50% shade. The 30%, 50% and insect-proof nettings provided complete protection, and the 15% netting reduced disease incidence to <2%, compared with>37% in the uncovered control plot. Spraying plants at weekly intervals with a commercial whitewash solution was also found to be effective in reducing disease incidence. The advantages of using a range of netting field treatments as a simple means for obtaining information on the epidemiological nature of a new disease are described.  相似文献   

高压无气喷涂工艺在大型储罐上的应用     

杨占品  范传宝  鲍善彩 《油气储运》2006,25(6):52-54

分析了大型储罐传统防腐涂装方式的特点,指出了采用新型涂装方式的必要性,介绍了高压无气喷涂工艺的预处理、实施及注意事项,分析了高压无气喷涂工艺的实施效果,提出了储罐防腐的建议.  相似文献   

几种叶面肥料在小菊上的筛选与应用研究     

马燕  刘育俭 《农业科技与信息》2006,(12)

试验采用单因素随机区组设计,叶面喷施肥料的施肥方法,应用方差分析和多重比较分析试验数据,从而筛选出小菊最佳的营养元素配方。试验从不同叶面肥料在小菊上的筛选与应用研究的试验结果得到：小菊对肥料具有较强的选择性：三高灵的施用能够增加小菊的开花数量和鲜叶片叶绿素的含量；宝力丰的施用能提高小菊单株的干物重；OPAL的施用能延长小菊开花的花期。  相似文献   

要正确对待西部种草   总被引：35，自引：9，他引：26  

任继周  侯扶江 《草业科学》2002,19(2):1-6

西部种草需要正确对待几个问题：良种不是绝对的，与环境协调发展的就是好草种；种草的效益不是单方面的，不是追求单方面的效益；人工草地是现代农业的必要组分，同时不要忽视天然草原；种草不要忽视灌木，清除灌木要慎重；种草要有必要农业投入，应该用好地种草；要以发展动物生产和饲料工业为重点，完善草地农业系统；管理是草业的命脉，应尽早达到草业生产数字化。  相似文献   

二化螟在茭白上的钻蛀行为及其防治方法   总被引：2，自引：1，他引：2  

俞晓平  郑许松  徐红星  陈建明  张珏锋 《植物保护学报》2004,31(1):26-32

研究了二化螟在茭白植株上的转移、钻蛀和产卵行为以及取食选择性,并根据其行为特性,制订合理的药剂喷施方法.结果表明,二化螟90%以上的卵产在茭白的叶片上,其余部分产在叶鞘上.产卵的主要叶位是心叶、倒一叶和倒二叶.超过50%的卵块集中在叶片距叶枕0～60cm的部位.幼虫孵化后,蚁螟蛀入的部位一般在叶枕以下的叶鞘内侧,多集中于倒四、倒五叶鞘.2龄后开始钻蛀内侧叶鞘,并蛀入茭白茎的内芯,二化螟幼虫在茭白植株上通常从叶片转移到叶鞘进行钻蛀危害.幼虫嗜食茭白茎部,其次为茭白果肉和叶鞘,对叶片几乎不取食.使用叶鞘喷施杀虫可达到对茭白进行全株喷雾同样的防治效果,并可节省40%～50%的用药量,经济和生态效益十分明显.  相似文献   

Analytical validation of platelet microparticle quantification in cats          下载免费PDF全文

Signe E. Cremer  Jørgen Koch  Nanna Graversen  Anne S. Gravgaard  Rebecca Langhorn  Annemarie T. Kristensen  Jakob L. Willesen  Lise N. Nielsen 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2018,47(3):386-395

  相似文献   

现代机械制造工艺与精密加工技术探析     

孙涛 《湖南农机》2016,(8)

社会主义市场经济逐年发展，各行各业都在不断成长，机械制造工业也有了较大的发展，现代机械制造工艺的运用渐渐成熟。但是我国的机械制造基础比较薄弱，现代机械制造工艺与精密加工技术都需要深层的研究和实践。文章阐述了现代机械制造工艺和精密加工技术的基本情况，并分析了它们的特点，希望能够以此对现代机械制造工艺与精密加工技术有个明晰的介绍。  相似文献   

Genome-edited crops: how to move them from laboratory to market     

Kunling CHEN  Caixia GAO 《农业科学与工程前沿(英文版)》2020,7(2):181-187

Recent breakthroughs in CRISPR technology allow specific genome manipulation of almost all crops and have initiated a revolution in precision crop breeding. Rationally-based regulation and widespread public acceptance are needed to propel genome-edited crops from laboratory to market and to translate this innovative technology into agricultural productivity.  相似文献   

自动施肥系统开发与性能测试     

李明仁  芦阳  李东燕  张万罡  马庆安  贺正  刘扬  马富裕 《新疆农业科学》2021,58(12):2228-2235

目的 开发一种适应于以固态水溶肥为原料的自动施肥系统,测试分析自动施肥系统性能。方法 主控机采用ARM9电路控制模块可实现对轮灌编组、预搅拌时长、施肥开始与结束时间、施肥持续时长、施肥量等参数的设置;选择以蠕动泵为注肥装置,通过变频器控制注肥泵电机功率的方式控制注肥速率,控制施肥量。对装置核心部件搅拌器额定功率、计量方式、溶肥搅拌参数、排肥速度及固液相比例等主要参数等进行设计与测试。结果 电感脉冲计量方式标准误差最大值1.26%,误差小、性价比好,确定其为本装置采用的计量方式;搅拌器以1.5 Kw额定功率、38 r/min转速搅拌、肥液浓度在1.1~1.3 g/mL、预搅拌时间30 min时,罐内各液位输出肥液浓度值差异不显著(P< 0.05),达到对肥料浓度均匀性的设计要求。结论 将施肥开始前的预搅拌时间设为30 min、搅拌转速设为38 r/min、肥液浓度不高于1.3 g/mL,输出肥液浓度有较好的均匀性,实现精准施肥。  相似文献   

Design and Experiment of Slave Computer Control System for Applying Variable-rate Liquid Fertilizer     

Zhang Ying-zi  Chen Hai-tao  Hou Shou-yin  Ji Wen-yi  Ouyang Bin-lin  Dun Guo-qiang  Zhang Ji-cheng 《东北农业大学学报(英文版)》2015,(2):73-79

In order to increase the applying rate of liquid fertilizer and reduce environmental pollution, a slave computer control system for applying variable-rate liquid fertilizer was designed. The system used SMC as core processor and electrically controlled pressure regulator as execution component. The characteristic equation of the system was obtained by using classical control theory. Results indicated that the characteristic equation met the requirements of routh-criterion, which indicated the working process of the system was stable. Performance of the slave computer was verified via bench tests. Results demonstrated that there was no significant influence on the response from interclass error. The fertilization error was less than 0.9, and the fertilization accuracy was larger than 97%. The liquid fertilizer emitted by the fertilizing devices had no significant difference in uniformity, which met the demands of the slave computer control system for applying variable-rate liquid fertilizer.  相似文献