AEC to Referee, Not Promote, Industry

A major turnabout in the attitude of the Atomic Energy Commission toward the nuclear power industry was signaled last week by the ntew AEC chairman James R. Schlesinger. With patrician froideur, Schlesinger informed a mass gathering of the nuclear power industry at Bal Harbour, Florida, that from henceforth the AEC woLuld act as the referee of nuclear power, not its promoter. Saying he would dispense with the "anecdotes and clumsy jests" customary on such occasions, Schlesinger served notice on the nuclear banqueters that their cozy relationship with the AEC was at an end. The industry should not expect the AEC to fight its battles: it should take its own case to the public-as the Sierra Club does. Nor did the AEC intend to bend the rules in industry's favor. "We have had a fair amount of advice on how to evade the clear mandate of the federal courts. It is advice we did not think proper to accept," Schlesinger said. Even on matters of engineering quality, the diners were told they knew full well they had "reason to blush." Roused out of any postprandial euphoria by this glacial disdain, the industry representatives heard the new chairman announce the following radical upheavals in official AEC philosophy.     

一串红栽培指南

参考品种 展望系列(Vista Series) 猩红国王(Scarlet King)) 猩红王后(Scarlet Queen)) 火焰(Flare) 埃特纳火山(Etna) 乐园(Paradiso) 胜地(Marbella) 花腔女高音(Melba) 栽培参数 单位种子数量:256粒/g 发芽适温:21～24 ℃ 发芽天数:4～8 天 栽培适温:15～21 ℃ 栽培周期:10～12 周 花园高度:25～35 cm 种子播后用蛭石覆盖     

从绿化,到美化,再到绿地文化——我国园林绿化发展大方向的探讨

本文对绿化、美化和绿地文化的释义进行了详尽地阐释,系统介绍了绿化技术及环境美化、绿地文化创造与表现的手法。在此基础上提出:绿化、美化、绿地文化既同属于园林绿地建设的三个方面,又是城市及国土绿化长期发展的三个阶段,在进行园林绿地建设和国土绿化时要分别进行横向和纵向地联系、贯彻,同时对于未来城市绿化的发展给予研究开发绿化手法多样性的建议。     

Nonconversion of o,p'-DDT to p,p'-DDT in rats, sheep, chickens, and quail

The finding of appreciable quantities of p,p'-DDT after feeding o,p'-DDT to rats led to the proposal of a theory, that an isomeric metabolic conversion occurs. The presence of p,p'-DDT as an impurity in supposedly pure samples of o,p'-DDT is the correct explanation for the appearance of p,p'-DDT. Purified o,p'-DDT and (14)C-labeled o,p'-DDT yielded no data to support the idea that o,p'-DDT is converted to the p,p'-DDT isomer.     

Sensitivities of Phytophthora infestans to Metalaxyl, Cymoxanil, and Dimethomorph

The isolates of Phytophthora infestans on tomato in the Guangxi Zhuang Autonomous Region, China, were determined for the sensitivities to metalaxyl, cymoxanil and dimethomorph to give the basic information for integrating disease management. Sensitivities were tested by measuring the radial growth on agar medium amended with fungicide, compared with the floating-leaf-disk method. 239 isolates were collected from eight tomato growing areas during 2000-2006. The testing results indicated that the frequencies of sensitive, intermediate, and resistant isolates to metalaxyl were 42.26, 35.98, and 23.53%, respectively. Variations in sensitivities amongst isolates from different areas or different years were very high for metalaxyl. All isolates from Tianlin and Wuxuan were sensitive to metalaxyl, but the metalaxyl-resistant isolates predominated in Tianyang, with the frequency of 51.35%. The EC50 values of certain isolates from Tianyang were higher than 500 μg mL-1 and their resistance levels were over 100000 folds. Cymoxanil has been used for nearly 10 years in Guangxi, and dimethomorph has been used for 5-6 years. However, there was no decrease in sensitivity of P. infestans populations and the sensitivities of the pathogen were nearly normally distributed. Hence, their mean EC50 value [cymoxanil (0.1647±0.0255) μg mL-1, dimethomorph (0.0970±0.0052) μg mL-1] could be used as the baseline sensitivities for monitoring the field resistance development. The comparison with the floating-leaf-disk method indicates that both the techniques provided equivalent results. These studies suggested that metalaxyl can be continuously applied in Tianlin, Wuxuan, and Nanning due to the resistant isolates that have not been found, while for those areas with resistant isolate, the use of metalaxyl should be reduced or alternated, and cymoxanil or dimethomorph was recommended for controlling late blight disease of tomato.     

番茄晚疫病菌对甲霜灵、霜脲氰和烯酰吗啉的敏感性检测

 【目的】研究广西番茄晚疫病菌对甲霜灵、霜脲氰和烯酰吗啉的敏感性,以期为该病的综合治理提供科学依据。【方法】用菌落生长直径法测定病菌对甲霜灵、霜脲氰和烯酰吗啉的敏感性,并用叶盘漂浮法加以比较。【结果】2000～2006年,从广西8个冬春植番茄区采集分离了239个菌株,测定结果表明,对甲霜灵表现为敏感型、中间型和抗性型的频率分别为42.26%、35.98%和23.53%,不同地区和年份的菌株对甲霜灵的敏感性差异很大。来自田林县、武宣县的菌株均为甲霜灵敏感性菌株,但在田阳县,抗甲霜灵菌株占优势,抗性频率高达51.35%,一些菌株的EC50值在500 µg•ml-1以上,抗性水平超过105倍。虽然霜脲氰在广西使用了近10年,烯酰吗啉也已应用了5～6年,但并未检测到番茄晚疫病菌对它们的敏感性下降的抗药性亚群体,病菌的敏感性接近正态分布,因此可以采用它们的平均EC50值（霜脲氰0.1647±0.0255 µg•ml-1,烯酰吗啉0.0970±0.0052 µg•ml-1）作为抗药性监测的敏感性基线。叶盘漂浮法测定结果与菌落生长直径法一致。【结论】广西田林县、武宣县和南宁市番茄晚疫病菌尚未出现抗甲霜灵菌株,仍可用甲霜灵来防治该病,而其它地区则应减少或不使用甲霜灵,改用霜脲氰或烯酰吗啉。     

辣椒氮、磷、钾、镁肥效应研究

为促进辣椒平衡施肥,以田间试验方法研究辣椒对氮、磷、钾、镁4种营养元素效应,试验表明氮、钾、镁对辣椒产量有显著的影响,与OPT处理相比,OPT-N、OPT-K、OPT-Mg处理分别减产38.2%、36.6%和21.8%。施钾能显著增加辣椒果实维生素C含量。施肥影响到辣椒叶片、茎干和果实对营养成分的吸收。此试验OPT处理的N、P2O5、K2O、MgO肥料利用率分别为22.9%、2.4%、33.4%和4.0%。每形成1000kg辣椒果实吸收3.69kg的N,0.53kg的P2O5,4.15kg的K2O和0.38kg的MgO,辣椒吸收N、P2O5、K2O、MgO的比例约为1:0.14:1.12:0.10。     

小麦、毛苕和豌豆对磷肥的反应

试验表明,无论是豆科还是禾本科作物,其籽粒增产量和生物学产量与磷肥用量呈极显著的正相关。小麦对磷肥反应比所谓“喜磷”的豆科作物并不逊色,每公斤P_2O_5可增产小麦生物学产量38.9kg/亩,比豆科作物高出56.3％～84.1％;可增产籽粒19.6kg/亩,比豆科作物高62.7％～108.1％;由于施用磷肥,小麦籽粒的增产量比豆科作物的干物质增产量还高7％～13％.单位面积上小麦吸收的总磷量比毛苕和豌豆分别高出38％和55％,从肥料中吸取的磷素比豌豆略高,而低于毛苕。磷肥利用率也是如此。整体看来,小麦对磷肥的反应比豆科作物的毛苕、豌豆更敏感。