落叶松人工林生态场中单株营养效力的分布

通过落叶松人工林单株土壤中营养元素分布的测定，指出了落叶松人工林生态场中，影响干涉势的营养效力因子的作用，同时发现这种分与地下生物量的分布是一致的。     

唑嘧磺草胺WG对大豆田阔叶杂草的防除效果及安全性

为了解80%唑嘧磺草胺WG土壤处理对大豆田阔叶杂草的除草活性及对大豆的安全性,参照GB/T17980.40—2000进行田间除草活性试验。结果表明,80%唑嘧磺草胺WG对大豆田地锦、鳢肠防效最好,对铁苋菜、小藜防效稍差,施后18 d的总草株防效为79.84%～98.72%,施后35 d总草株防效为81.93%～99.66%,施后35 d鲜重防效达80.76～99.77%,大豆增产幅度为7.91%～15.47%。80%唑嘧磺草胺WG作为土壤处理,在大豆田最佳使用剂量为56.25～75g/hm2,用水量600L/hm2,对大豆安全。     

埋地热油管道总传热系数的研究

总传热系数K在埋地热油管道的运行管理中是一个非常关键的参数,其取值是否合理将影响管道运行的安全性和经济性.对于埋地热油管道稳态运行过程,提出采用最小二乘法反算K值;对于非稳态运行过程,提出了一种双层耦合模型来计算K值.在分析实例的基础上,K值的变化幅度给予了量化,从而解决了从定性到定量的认识问题.在一定程度上,此模型和求解方法可以为埋地热油管道非稳态优化运行提供参考.     

多品种叶面肥水稻田间应用效果探析

[目的]为大面积推广应用多品种叶面肥提供科学依据。[方法]在水稻作物上施用不同品种的叶面肥产品,对比不同叶面肥产品在水稻上的应用效果和经济效益。[结果]在抽穗阶段喷施根外生长调节剂,取得较明显的效果。[结论]根外追肥取得良好的效果,可以继续推广。     

青虾稻田养殖技术

介绍了青虾稻田养殖技术,包括稻田选择与清整、放养前准备、青虾放养、饵料投喂、水质管理、防逃防害、病害防治、青虾收获等内容,以供参考。     

漏磁腐蚀检测器新型探头机构的设计

为了解决漏磁腐蚀检测器在管道内检测过程中因探头机构姿态不稳、偏磨及支撑弹簧易折断、易震颤带来的一系列问题,对检测器所用探头机构进行研究,设计制造了一种全新的探头机构.该机构增加了辅助支撑弹簧和柔性连接铰链,很好地解决了传统探头机构存在的不足.该机构的检测探头将以往探头加耐磨层结构变为整体灌装探头壳形式,改善了检测探头的提离值,提高了检测信号的可靠性.与传统探头机构相比,该机构的使用能够有效提高检测数据的可靠性和稳定性.     

一种植物病毒检测新方法—纳米上转换荧光技术

随着大豆进口量的日益增加,大豆携带病毒传入我国的风险在不断增大,高效、快速地进行植物病毒检测,防止外来有害生物入侵,是目前各口岸植物检疫工作的重点。本文介绍了一种植物病毒检测的新方法—纳米上转换荧光技术。该技术是一种利用磁性纳米颗粒(magnetic nanoparticles, MNP)进行病毒分离、富集和定位;同时引入上转换荧光(up converting phosphor, UCP)材料作为标记物的免疫检测方法,具有高度的抗干扰性、多元性、稳定性和安全性等特点。     

Laboratory and field comparisons of insecticides to reduce infestation of Drosophila suzukii in berry crops

BACKGROUND: The spotted wing Drosophila, Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae), is an invasive pest of small‐fruit crops. Unlike most other Drosophila, this insect is able to oviposit into and damage ripe and ripening fruit, making it unmarketable. Because this is a new pest in the United States, it is necessary to identify registered insecticides to manage this insect effectively in conventional and organic production systems. RESULTS: The present laboratory bioassays and field trials identified a number of insecticides representing various modes of action that are effective in controlling D. suzukii. Products that performed well in the laboratory bioassay also performed well in the field, indicating that screening of new chemistries in the laboratory is a worthy exercise. Field application of pyrethoids, organophosphates or spinosyns provided 5–14 days of residual control of D. suzukii. The efficacy of the neonicotinoids as adulticides was not satisfactory compared with the other contact‐mode‐of‐action chemistries. Based on the zero tolerance by the small‐fruit industry and the individual effects mentioned above, neonicotinoids are not currently recommended for D. suzukii management. CONCLUSIONS: There are effective insecticides registered for controlling D. suzukii infestations in susceptible small‐fruit crops. Copyright © 2011 Society of Chemical Industry     

Spray drift as influenced by meteorological and technical factors

BACKGROUND: The objective of this study was to investigate spray drift from a conventional field sprayer as influenced by meteorological and technical factors, and to provide spray operators with data on which to base sound judgements when applying pesticides. The study was conducted in grazing fields and cereal crops. RESULTS: Interpreting the results from 15 field trials under varying meteorological conditions using different boom heights and driving speeds indicates that, during normal spraying conditions, the most decisive factors influencing the total spray drift (TSD) will be boom height and wind speed, followed by air temperature, driving speed and vapour pressure deficit. One important finding was that TSD (within the encompassed range of meteorological conditions and a boom height of 0.4 m) could be expressed as a simple function of the fraction of droplets ≤ 100 µm. In cereal crops: TSD = 0.36 + 0.11× [fr. (d ≤ 100 µm)] and in grazing fields, TSD = 1.02 + 0.10× [fr. (d ≤ 100 µm)]. In most cases a fraction of the airborne drift passed over the 6 m sampling mast located 5 m downwind of the spray swath. CONCLUSIONS: Under specified conditions, the present results indicate a simple relation between the total spray drift and volume fractions of droplets ≤ 100 µm. Given the nozzle type, it was concluded that the most decisive factors determining TSD are wind speed and boom height. Evaluating the relative importance of the meteorological and technical factors contributes to increasing knowledge in this field of research. Copyright © 2011 Society of Chemical Industry     

Inconspicuous restraint of rice seedling growth by root-infecting fungi in soil of a rice paddy field

 Rice seedling growth, estimated by plant height and root development and discoloration, was better in pasteurized soil than in unpasteurized soil obtained from a flooded rice field. Rice seedlings also grew better in sterilized soil modified by adding roots harvested from the pasteurized soil than in soil modified by adding roots harvested from the unpasteurized soil. The results demonstrate that seedling growth in the rice field soil was inhibited by soil microorganisms, even though no typical symptoms such as seedling blight or damping-off appeared. Pythium aristosporum is suggested to be involved in the inhibition. Thus, it appears that inconspicuous restraint of rice seedling growth could occur in soils of rice paddy fields. Received: May 20, 2002 / Accepted: October 16, 2002 Acknowledgments The authors thank Dr. T. Ichitani, former professor at Osaka Prefectural University, for providing an isolate of Pythium aristosporum for comparison, and Mr. Mitsuaki Sato of Akita Prefectural College of Agriculture for technical assistance.