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971.
百菌清烟剂防治黄瓜霜霉病相关技术试验 总被引:1,自引:0,他引:1
研究了保护地条件下百菌清系列烟剂有效成份含量、施药量、施药次数、间隔期4项植保措施与黄瓜霜霉病防治效果的关系。参试4因子中以1次施药量作用最大。最优方案为:百菌清烟剂有效成份含量30%,每次施药量300g/667m2,间隔8d(天),连施4次。 相似文献
972.
超干处理和贮藏对番茄和辣椒种子生活力和活力的影响 总被引:12,自引:1,他引:11
试验采用氧化钙为干燥剂对番茄和辣椒种子进行超平处理和贮藏,以研究其对种子生活力和活力的影响。结果表明,番茄种子水分降至3.77%、辣椒种子水分降至3.86%,未发现对种子生活力和活力有明显的影响;对不同含水量的番茄和辣椒种子室温密闭贮今6个月后的调查结果发现,超低水分种子生活力和活力较高,细胞膜能保持较好的完整性,脱氢酶活性和呼吸强度较高。由此可见超干贮藏有利于保持番茄和辣椒种子的生活力和活力。 相似文献
973.
武威地区天然草地有毒植物及其防除 总被引:12,自引:2,他引:10
对武威地区天然草地有毒植物的种类,分布及其对草地的危害情况进行了调查研究,结果表明,全区天然草地共有毒植物172号,分属31科84属,平均2.15种/m^2,盖度达4.41%地上部分生物量11.28g/m^2。对草地危害的主要黄花棘豆,甘肃棘豆,小花棘豆,狼毒和马草,受侵害的草地主要是山地草甸和山地草原,通过分析,提出了有毒植物防除和利用的建议。 相似文献
974.
975.
香石竹叶斑病防治研究 总被引:1,自引:0,他引:1
本文报道作者等于1978~1980年间对香石竹叶斑病的防治研究结果。此病主要为害叶片造成叶斑和叶枯,但也可造成茎腐和花枯。根据本病原分生孢子色泽较深、喙较短、纵向斜向分隔较多等特点,确认上海地区香石竹叶斑病病原为Alternaria dianthi Stev.et Hall而非Alternaria dianthicola Neerganrd。对其形态大小进行了描述。土中病残体是此病的初次侵染源。越冬后的分生孢子是此病的初侵染源菌态之一。霉季和台风季多雨.露地栽培、种植感病品系均有利于发病。栽培措施可以减轻发病程度。试验证明防病有效的药剂有:土壤消毒可以0.1%五氯硝基苯拌土;插条浸药:10%401的1000倍液浸半小时或0.1%高锰酸钾液浸10分钟;生长季节喷雾:0.5%的波尔多液或75%的代森锰锌500倍液,10天1次,在每次摘芽作业后及时喷施。 相似文献
976.
松树枯梢病潜伏侵染的研究 总被引:5,自引:0,他引:5
研究表明在火炬松、湿地松、短叶松和马尾松健康梢上整年都能分离到松枯梢病菌,其中在火炬松上的得菌率为15%—37.7%,且大多数月份高于20%;湿地松上的得菌率稍低于火炬松,为7.5%~29.1%;短叶松梢上的得菌率是13.8%—57.1%,月份之间的差异较大;马尾松得菌率最低,为9.7%—22.4%,多数分离得菌率低于20%。健康梢的不同部位得菌率有一定差异,枝和新梢较高,芽稍低,叶最低。在1年中,健康梢上得菌率有3个高峰期,即4—5月、7—8月和10—11月,是潜伏侵染的的主要时期。将健康芽和梢进行诱发培养,lOd后组织块上及周围产生松枯梢病菌的分生孢子器,得菌情况与常规分离相似。在当年孢子散发之前,对健康梢套袋隔离试验,发现套袋梢仍会发病,说明在发病的春梢中,有一部分是由于潜伏侵染的松枯梢病菌造成的。从而证明松枯梢病菌在火炬松、湿地松、短叶松和马尾松上普遍存在潜伏侵染。 相似文献
977.
978.
The lateral transmission of Histomonas meleagridis in turkeys was studied in floor pens without the presence of Heterakis gallinarum. Battery-reared poults (120) were transferred at 2 wk of age to concrete-floored floor pens with fresh pine shavings litter (40/group). One group received no exposure. In other groups, either 10% or 25% of the birds were inoculated per cloaca with cultured H. meleagridis (200,000/bird) and placed in the pens as seeder birds. Inoculated birds died at 10-18 days postinfection (PI) showing typical liver and cecal lesions of histomoniasis. Birds in the high-exposure group died of histomoniasis beginning 16 days PI and continuing to 100% mortality by day 23 PI. Birds in the low-exposure (LE) group died beginning on day 19 PI and continuing through day 31 PI. All but one LE bird alive on day 31 PI had severe liver and cecal lesions of histomoniasis at necropsy. There was no evidence of histomoniasis in unexposed birds. No cecal worms (H. gallinarum) were found at necropsy of dead birds or in unexposed birds at the end of the experiment. Even though H. gallinarum is the only known reservoir for H. meleagridis, these results suggest that lateral transmission of histomoniasis through a flock can occur readily through normal contact between uninfected birds and infected birds and their droppings in the total absence of cecal worms. 相似文献
979.
Afferent and efferent connections of the nucleus rotundus demonstrated by WGA-HRP in the chick 总被引:5,自引:0,他引:5
Organization of the fibre connections in the chick nucleus rotundus (Rt) was investigated by an axonal tracing method using wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP). After an injection of WGA-HRP into the Rt, labelled neurones were observed in the striatum griseum centrale (SGC) in both sides of the tectum (TO) and in the ipsilateral nucleus subpretectalis/nucleus interstito-pretecto-subpretectalis (SP/IPS). Labelled fibres and terminals were also found in the ipsilateral ectostriatum (Ect). These fibre connections were topographically organized rostrocaudally. In the TO-Rt projection, the rostral and the dorsocaudal parts of the Rt received afferents from the superficial part of the SGC, the middle part of the Rt received afferents from the intermediate part of the SGC, and the ventrocaudal part of the Rt received mainly fibres from the deep part of the SGC. These topographic projections were accompanied by a considerable number of diffuse projections to the thalamic regions surrounding the Rt. In addition, the rostral and middle caudal parts of the Rt received afferents from the lateral and medial parts of the SP/IPS, respectively, and respective parts of the Rt sent efferents to the lateral and medial parts of the Ect. 相似文献
980.
The aims of this study were to evaluate the effects of a ketamine/propofol anaesthetic protocol in lions (Panthera leo), and to compare it to two commonly used anaesthetic protocols. Seventeen adult lions were anaesthetised using three different protocols. Group XK (n=6) was anaesthetised with intramuscular (i.m.) injections of xylazine and ketamine. Group KD (n=5) was anaesthetised with an i.m. injection of ketamine, followed by an intravenous (i.v.) injection of ketamine and diazepam. Group KP (n=6) was anaesthetised with an i.m. injection of ketamine followed by an i.v. injection of propofol. There was a significant difference in heart rate (P<0.0002), which was lowest in group XK and highest in KD. Jaw tone was significantly lower in Group XK (P<0.05). No undesirable effects were noted following injection of the propofol. Propofol was a suitable and safe drug for maintenance of anaesthesia in adult lions. 相似文献