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用Fuzzy分析方法预报稻纵卷叶螟第三代发生程度 总被引：1，自引：0，他引：1
通过对锦屏且１９８４年至１９９６年历史资料整理分析,第三代稻纵卷叶螟发生程度与５月下旬至６月上旬糖醋排下迁入期蛾量,６月上旬雨量,气温相关,应用Ｆｕｚｚｙ分析方法对第三代稻纵卷叶螟发生程度进行综合评判分析,预测,历史符合率达９３．８％,并得知影响发生程度的关键因子是５月下旬至６月上旬排下主迁入期蛾量。 相似文献
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2004年梧州市第6代稻纵卷叶螟为大发生,部分田块达到特大发生程度,是近15a来罕见的;而常年发生程度为轻,最重年份2002年是中等偏轻局部中等程度发生.2004年第6代稻纵卷叶螟的大发生对我市水稻产量造成较严重的影响,失治及防效差的田块出现一片白叶现象,分析其发生原因,为今后开展测报和防治提供参考. 相似文献
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为探明湖南省中部地区五(4)代稻纵卷叶螟的发生与气象条件的关系。本文利用娄底市2007-2014年期间稻纵卷叶螟的观测数据和气象数据,采用相关性分析和通径分析等方法,分析了五(4)代稻纵卷叶螟发生的气象特征,并建立了五(4)代稻纵卷叶螟发生程度的预测模型。研究结果表明:温湿系数、相对湿度、日平均气温以及降水日数是影响五(4)代稻纵卷叶螟发生的主导决定因子,其中温湿系数的直接和间接作用最大,表明五(4)代稻纵卷叶螟对温度和湿度有较高的要求;五(4)代稻纵卷叶螟蛾高峰期出现的适宜气象条件为:温湿系数大于2.4,气温26~30℃,相对湿度在80%以上,且蛾高峰期出现的前两天和当天有降水的概率为88.9%。本文研究结果可为湖南省中部地区稻纵卷叶螟的准确测报和科学防控提供参考。 相似文献
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1水稻病虫1·1稻飞虱、稻纵卷叶螟预计第3代稻飞虱在鄂东南、鄂西南发生程度为5级(大发生,下同),鄂东沿江、江汉平原南部发生程度4级(中等偏重,下同),其它地区3级(中等发生,下同);第4代、第5代稻飞虱全省4~5级。预计第2代稻纵卷叶螟发生程度3级,第3代稻纵卷叶螟全省发生程度4级,局部5级,第4代稻纵卷叶螟4~5级。1·2二化螟预计第2代二化螟全省大部发生程度为5级,鄂西南2级。卵孵盛期南部稻区7月4日至7月25日;北部稻区7月18日至8月5日;第3代二化螟在江汉平原、鄂东南、鄂东沿江稻区发生程度4级,局部5级。1·3三化螟预计第2代三化螟在全省大部… 相似文献
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2007年上半年,水稻"两迁"害虫在宁明县中等偏重、局部大发生为害,第2代、第3代水稻"两迁"害虫发生面积达0.682万ha次,占早稻种植面积的124.24%;水稻"两迁"害虫发生的特点是:稻飞虱和稻纵卷叶螟同时发生为害,世代重叠,发生为害时间长,第2代稻飞虱比第2代稻纵卷叶螟发生重,第3代稻纵卷叶螟比第3代稻飞虱发生重. 相似文献
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1 水稻病虫 1.1 稻飞虱、稻纵卷叶螟 预计第2代稻飞虱4级发生(中等偏重),鄂东局部5级(大发生);第3代、第4代、第5代稻飞虱全省5级.预计第2代稻纵卷叶螟4级发生,局部5级,第3代、第4代稻纵全省5级. 相似文献
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2008年稻纵卷叶螟[Cnaphalocrocis medinalis（Guenée）]在盘县大发生,虫量大,范围广,为害严重,发生程度是盘县近20年来最为严重的年份。由于各级业务部门和政府高度重视,广大农户积极防治,对第四代稻纵卷叶螟的防治效果好,大面积水稻为害损失控制在3％以下,损失较小。现就2008年稻纵卷叶螟发生为害情况,进行分析总结。 相似文献
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F.M. Ashton O.T. de Villiers R.K. Glenn W.B. Duke 《Pesticide biochemistry and physiology》1977,7(2):122-141
Time- and concentration-course studies were conducted to determine the effect of thirteen herbicides on photosynthesis, respiration, RNA synthesis, protein synthesis, and lipid synthesis using isolated single leaf cells. Each herbicide was from a different chemical class. Appropriate 14C-substrates and product purification procedures were used for each process prior to liquid scintillation counting. The most sensitive metabolic site of inhibition was photosynthesis for atrazine, bromacil, dichlobenil, monuron, and paraquat; RNA synthesis for dalapon and dinoseb; protein synthesis for chlorpropham; and lipid synthesis for CDAA, chloramben, 2,4-D, EPTC, and trifluralin. However, with several herbicides, one or more process was almost as sensitive as the one mentioned above. All herbicides inhibited more than one process, and the most sensitive site of inhibition may not be the same process that was inhibited the greatest at the maximum concentration and maximum exposure time used. Therefore, a concept of metabolic sites of action, rather than a primary site of action, appears to be more meaningful for herbicides. 相似文献
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福寿螺配偶个体大小选择性初步观察 总被引：7，自引：0，他引：7
通过野外观察与实验研究,掌握了福寿螺的婚配体制及其配偶选择性规律。福寿螺与多数低等动物一样,其婚配属于乱交制,无固定配偶;雌螺对与其交配的雄螺个体大小没有选择性,而雄螺对雌螺的个体大小有选择性,倾向于与较大个的雌螺交配。 相似文献
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E. LIMPERT B. C. CLIFFORD A. DREISEITL R. JOHNSON K. MÜLLER A. ROELFS C. WELLINGS 《EPPO Bulletin》1994,24(1):109-112
A variety of systems of designation has evolved to name pathotypes of plant pathogens. The systems were evaluated to determine those best suited for particular purposes. Virulence and avirulence/virulence formulae of pathotypes have advantage over the use of consecutive numbers or letters given in chronological order of pathotype discovery. As soon as pathotype information exceeds a certain level of complexity, mathematical codes are most advantageous, in particular two codes, octal notation and coded triplets. A more universal adoption of the most appropriate codes is recommended to ease communication and comparisons of results. 相似文献
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调查了甘肃省临洮县为害百合的地下害虫种类, 并以主要发生为害种类为供试对象, 采用拌土法测定了几种生物（源）农药对主要害虫的室内毒力和致死中时。调查发现小云斑鳃金龟Polyphylla gracilicornis、棕色鳃金龟Holotrichia titanis为主要发生及为害种类, 不同时间发生种类存在差异, 9月份以小云斑鳃金龟幼虫发生为害为主, 发生量占地下害虫总数的66.16%, 平均种群密度为10.48头/m2, 10月份, 则以棕色鳃金龟幼虫发生为主, 发生量占地下害虫总数的96.86%, 平均种群密度为7.79头/m2, 主要取食百合根系和鳞茎, 造成根系数量减少, 鳞茎出现不规则褐色缺口或凹陷斑。药剂筛选结果表明, 1.8%阿维菌素乳油、200亿孢子/g球孢白僵菌粉剂对两种蛴螬均具有较高的杀虫活性和速效性, 药后7 d时, 校正死亡率在82.22%以上, 对小云斑鳃金龟幼虫和棕色鳃金龟幼虫的LC50分别为0.161、0.060 mg/g和5.558×107、0.362×107孢子/g, LT50分别为2.237 d（2.2 mg/g）、1.393 d（2.2 mg/g）和6.645 d（40.0×107孢子/g）、4.940 d（2.0×107孢子/g）, 这两种生物（源）农药对两种蛴螬的LC50和LT50值均略大于两种化学农药25%二嗪磷乳油、40%辛硫磷乳油处理的, 且对小云斑鳃金龟幼虫的杀虫活性均低于对棕色鳃金龟幼虫的杀虫活性, 致死中时则长于对棕色鳃金龟幼虫的致死中时。 相似文献
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Effects of timing and method of application of Penicillium oxalicum on efficacy and duration of control of Fusarium wilt of tomato 总被引：3，自引：0，他引：3
The effects of timing and method of application of Penicillium oxalicum on the control of fusarium wilt of tomato were investigated. Application of P. oxalicum to tomato seedlings in seedbeds reduced disease caused by Fusarium oxysporum f.sp. lycopersici in a growth chamber by 45–49% and in glasshouse experiments by 22–69%. Disease suppression was maintained for 60–100 days after inoculation with the pathogen in the glasshouse. No disease reduction was observed in tomato plants where P. oxalicum was applied to seeds. Treatment with P. oxalicum did not affect the population of F. oxysporum f.sp. lycopersici in the rhizosphere. 相似文献
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为了研究青稞种子外部和内部携带真菌情况,比较不同杀菌剂对青稞种子的带菌消毒效果和对幼苗生长的影响,为青稞种子播前包衣处理和种传真菌病害防控提供依据,采用离体平皿法对云南迪庆‘云青1号’、‘云青2号’和‘短白青稞’3个主栽品种进行带菌检测,并对种子进行拌种或浸种处理测定6种杀菌剂对种子消毒效果,分析杀菌剂对种子发芽和幼苗生长的影响。结果表明:供试青稞种子表面携带的优势菌群为青霉(Penicilliumspp.)、镰刀菌(Fusariumspp.);种子内部寄藏的真菌主要为镰刀菌、核腔菌(Pyrenophoraspp.)、附球菌(Epicoccumspp.)、丝核菌(Rhizoctoniaspp.)、链格孢(Alternariaspp.)和木霉(Trichoderma spp.)。青稞不同品种的种子表面及内部携带的真菌种类差异较大。致病性测定表明,镰刀菌对种子萌发和幼苗生长影响最大,后期出现幼苗坏死现象。45%咪鲜胺EW、75%百菌清WP、50%福美双WP对青稞种子携带真菌均有显著抑制作用和消毒效果,50%福美双WP消毒效果最优,达100%;45%咪鲜胺EW、75%百菌清WP、50%福美双WP处理对青稞种子发芽和幼苗生长均无显著影响。 相似文献
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Magdalina I. Luzhnova Lyudmila M. Shekhtman 《Pesticide biochemistry and physiology》1975,5(3):205-210
The effect of meturine on the light processes of photosynthesis was studied.Meturine is a herbicide for weed control in potato and cotton crops. It is a N-phenyl—N-hydroxy—N′-methylurea.The experiments were carried out on isolated pea and spinach chloroplasts.When examining photosystem I, reduced DPIP was used as an electron donor, whereas methyl-viologen served as an electron acceptor. When examining photosystem II, DPIP represented the electron acceptor.The obtained experimental results have pointed to the absence of the effect of meturine upon the photoreaction I.Unlike N-phenyl—N′, N′-dimethylureas (CMU, DCMU) meturine has been a very weak inhibitor of photoreaction II.The authors explain the photoreaction II inhibition of chloroplasts from plants treated with herbicidal doses of meturine by conversion of N-phenyl—N-hydroxy—N′-methylurea into Hill reaction inhibitor(s). N-Phenyl—N′-methylurea can be one of such meturine metabolites.Meturine herbicidal action is accounted for by meturine transformation into Hill reaction inhibitor(s) in the plant tissues. 相似文献