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   

延边地区紫苏保护技术的研究     

吴明根  吴松权  杜晓军  崔锡花  曹凤秋 《延边大学农学学报》2004,26(3):158-165

紫苏是延边地区的重要经济作物之一．但目前随着种植年限的延续，开始大量发生虫害、病害以及草害等，从而导致减产、降效，严重影响苏子生产．研究结果表明，延边紫苏地适宜土壤处理的除草剂为敌草胺与扑草净的混剂，使用剂量为3kg／hm^2 5kg／hm^2，一年生杂草除草效果可达到90％以上；茎叶处理除草剂为拿捕净(12．5％，1．0kg／hm^2)、稳杀得(35％，1．0kg／hm^2)、精禾草克(5％，1．0kg／hm^2)；紫苏的主要病害为锈病，对紫苏叶片质量影响较大；主要食粒虫害(待定)对产量的影响较大．  相似文献   

Purification and some properties of Papaya meleira virus, a novel virus infecting papayas in Brazil     

E. Maciel-Zambolim †  S. Kunieda-Alonso  K. Matsuoka  M. G. de Carvalho  F. M. Zerbini 《Plant pathology》2003,52(3):389-394

'Meleira', or 'sticky disease', is currently the most damaging papaya disease in the mid-eastern Brazilian growing regions. Consistent disease transmission via latex injection, presence of similar isometric particles in the laticiferous vessels of diseased plants, and detection of double-stranded DNA in naturally and experimentally infected papaya trees suggest that a virus is the causal agent. Conclusive evidence for viral aetiology was previously lacking, mostly because every attempt to purify the putative virus from infected papayas had failed. Following the successful purification and partial characterization of the meleira virus, healthy papaya seedlings injected with purified virus particles later developed typical symptoms of the disease. Negatively stained, isometric, full and 'empty' purified virus particles measured 42 and 38 nm, respectively. The viral genome was a single dsRNA molecule of about 12 kbp. Several capsid proteins, ranging in size from 14·4 to 45 kDa, were consistently revealed by PAGE. Papaya meleira virus (PMeV) appears to represent a novel group of viruses, with no known similar counterpart among known plant-, vertebrate-, invertebrate- or prokaryote-infecting viruses.  相似文献   

Herbicide options for weed control in papaya     

R.K. NISHIMOTO 《Integrated Pest Management Reviews》1997,2(3):109-111

This paper reviews the literature on weeds and weed control in papaya. There is limited research on this topic, and nearly all of the research focuses on herbicides. Effective use of paraquat and glyphosate in papaya is dependent on avoidance of spray contact to green bark and foliage. Pre-emergence herbicide tolerance is dependent on papaya age, size and maturity, and soil type. Only one herbicide, oryzalin is shown to be tolerated by papaya immediately after transplanting. Herbicides such as diuron and oxyfluorfen with a broader spectrum of weed control generally injure young papaya, however they can be effectively used if the initial application of these herbicides is delayed until papaya attains certain size or maturity indices. There is a need for further research on weeds and weed control to improve the efficiency of papaya production  相似文献   

基于点评估方法的两广地区番木瓜中农药残留膳食暴露风险研究     

郭宏斌  刘福现  林玲  叶剑芝  杨春亮 《热带作物学报》2020,41(12):2548-2554

为评估两广地区番木瓜中主要农药的残留情况及其产生的风险,采集了广东、广西地区40个生产基地的番木瓜样品进行测试分析,研究其生产过程中使用的杀虫剂、杀菌剂、杀螨剂和植物生长调节剂等各种农药残留情况,并对我国不同人群的膳食暴露风险进行了评估。结果显示,40批次番木瓜中检出农药残留32批次;在检出的32份番木瓜样品中,检出率超过10%的有咪鲜胺、吡虫啉、多菌灵、啶虫脒和苯醚甲环唑5种农药,检出率分别为51.1%、21.5%、13.3%、11.1%、10.9%。采用点评估方法,选择检出率在10%以上的咪鲜胺、吡虫啉、多菌灵、啶虫脒和苯醚甲环唑,进行农药残留慢性膳食摄入风险（%ADI）评估、急性膳食摄入风险（%ARfD）评估,并进行不同消费人群暴露点评估。结果显示：检出的5种农药%ADI均低于100.00%,为0.00023%~0.0059%;%ARfD远低于100%,为0.50%~28.3%,5种农药的急性和慢性摄入风险均为儿童高于成年人,绝大多数女性的摄入风险高于男性;5种农药急性摄入风险均高于慢性摄入风险,风险水平由高到低为咪鲜胺>啶虫脒>苯醚甲环唑>多菌灵>吡虫啉,但点评估结果均远低于100%,说明通过食用番木瓜摄入的农药残留极其微量,不会对人体产生急性或慢性风险。  相似文献   

半干旱黄土丘陵区沙棘优良品种引种栽培试验研究     

李代琼  黄瑾  姜峻  白岗栓 《国际沙棘研究与开发》2003,1(2):23-27

1994-2003年在黄土高原半干旱区的陕西吴旗县、安塞县进行中国沙棘优良类型和俄罗斯优良沙棘品种引种试验,采用家系选择法初步筛选出5个中国沙棘生态经济型优良单株,对3个俄罗斯良种沙棘的生长适应性经济性状进行了评价。前者生长迅速、树冠好、根系发达、郁闭快、水土保持效益好,果实较大、单株产量较高、Vc和含油量较高,适于在黄土丘陵区种植;后者经济性状较好,果实大、无刺或少刺,但适应性较中国沙棘差。  相似文献   

微波消解-FAAS测定番木瓜不同部位的金属元素含量     

袁竹连 《河南农业科学》2013,42(1):143-147

为探讨番木瓜果肉、果皮、瓜籽中金属元素的含量,采用微波消解-FAAS法测定了番木瓜3个部位的K、Na、Ca、Mg、Cu、Fe、Zn共7种金属元素的含量,并对微波消解条件进行了优化。结果显示,在优化的微波消解条件下,样品消解完全、速度快、效果好,FAAS测定的各金属元素质量浓度与吸光度均呈良好的线性关系,相关系数r为0.995 7～0.999 9,检出限为0.002～0.131,回收率为98.30%～101.67%,RSD为0.20%～4.12%(n=6),说明测定方法可靠,结果稳定;番木瓜3个部位均含有较高的K、Ca、Mg,但Cu、Fe、Zn含量均较低,与番木瓜果肉相比,番木瓜果皮和瓜籽中K、Mg、Cu、Zn、Fe含量较高,食品和药品开发优势更突出。  相似文献   

通径分析在油纤兼用亚麻产量分析中的应用     

刘海龙  王世发  周玉萍  牛海龙  刘淑莲  潘亚丽  孙晓平  徐迟 《安徽农业科学》2012,40(11):6416-6417,6419

首先对18个胡麻(Linum usitatissimum Linn.)品系的5个产量构成性状及产量进行相关分析,指出单株粒数和分枝长与产量之间的相关性达显著水平,并且各性状之间还存在着相互作用、相互制约和相互促进的关系。因此对吉林省胡麻产量及其构成性状的关系须采用通径分析方法进行分析,以估算每一个性状对产量的直接作用,以及一个性状通过另一个性状对产量的间接作用。通径分析结果表明,在吉林省提高胡麻产量,可主要通过提高单株粒数和增加分枝数来实现;返青将致使胡麻减产。  相似文献   

地胆头注射液的制备及其体外抑菌效果研究     

陈进军  陈芳  邓选金 《中兽医医药杂志》2005,24(4):14-17

分别用3种不同浓度的乙醇水溶液进行热回流浸提,制备地胆头原液.然后用醇溶液调pH值法除去鞣质以及乙醚脱脂、活性炭脱色等方法进行除杂脱色,制备地胆头有效部位注射液.对地胆头注射液进行了质量和安全性检查及体外药效试验.结果表明,制备的地胆头注射液对金黄色葡萄球菌、肺炎双球菌、大肠埃希氏杆菌和肠炎沙门氏菌均有明显的抑制作用,其中用65%乙醇提取制备的地胆头注射液效果最好,3种注射液都具有很好的澄明度和安全性.  相似文献   

杀虫剂对2种麦蚜的敏感性和选择性测定   总被引：1，自引：0，他引：1  

刘爱芝  李世功  茹桃勤  王晓军 《农药科学与管理》2001,(Z1)

用浸叶法测定了麦长管蚜和黍缢管蚜对几种杀虫剂的敏感性和选择性。结果表明 ,麦长管蚜对几种杀虫剂的敏感性呈以下规律 :辛硫磷<毒死蜱<吡虫啉<抗蚜威<啶虫咪<氧化乐果<甲基对硫磷 ;致死中浓度 (LC50)按以下次序增大 :啶虫脒 ,辛硫磷 ,毒死蜱 ,抗蚜威 ,甲基对硫磷 ,吡虫啉 ,氧化乐果。黍缢管蚜对几种杀虫剂敏感性呈以下规律 :吡虫啉<毒死蜱<啶虫脒<抗蚜威<甲基对硫磷<氧化乐果 ,致死中浓度 (LC50)按以下次序增大 :啶虫脒 ,毒死蜱 ,吡虫啉 ,抗蚜威 ,甲基对硫磷 ,氧化乐果。麦长管蚜和黍缢管蚜对几种杀虫剂的选择性依次为 :啶虫咪<甲基对硫磷<抗蚜威<毒死蜱<氧化乐果<吡虫啉  相似文献