吉林省向日葵菌核病综合防治措施研究及大面积应用效果

在重茬4年的重病地块晚播(5月20日—25日)向日葵,其花腐型菌核病比正常播期(4月25日)减少90％以上,而产量提高13％—30％。在农村扩大示范,晚播(5月19日)减少病害59％—75％,产量提高35％。在盛花期—成熟期喷2—3次50％速克灵500倍液可大大减轻花腐型菌核病的发生(防治效果65.9％—92.3％)。经筛选以速克灵(0.5％)拌种防治根腐型菌核病效果最好,在温室中对土壤和种子中的病菌防治效果达83％以上,小区试验和农村示范防治效果达55.8％—100％。土壤中增施钾肥可提高植株抗病力,减轻发病。1990年在吉林省农安、长岭2县8533ha采用晚播、轮作2年以上、种子处理、增施钾肥、盛花期—成熟期喷药的一套综合防治措施,重点调查10块对比田,花腐型菌核病平均防治效果为87.62％(63.38％—100％),对根腐型菌核病防治效果平均为66.77％(50.0％—82.57％)。1991年在长岭、农安等6个主产区推广6.37万ha,重点调查134块对比田,花腐型菌核病防治效果平均为75.86％(46.37％—100％),根腐型菌核病平均防治效果为65.11％(33.33％—100％),增产增收显著。     

Quality versus quantity: spring wheat seed size and seeding rate effects on Avena fatua interference, economic returns and economic thresholds

A 3-year field experiment was conducted at Kalispell, Montana, USA, to investigate the effects of spring wheat seed size and seeding rate on wheat yield loss (YL), economic returns and economic thresholds (ETs), as a function of Avena fatua density. Crop competitive ability increased as wheat seeding rate and seed size increased, with the greatest differences among treatment factors being observed at low weed densities. Both treatment factors decreased spring wheat YL, increasing economic returns during all 3 years of the study despite the higher associated seed costs. Averaged over all other factors, adjusted gross returns (AGR) were 477 and 537$ ha⁻¹ for the low and high seeding rates, while values of 453, 521 and 547$ ha⁻¹ were obtained for the small, bulk and large seed size classes respectively. Weed-free yield potential varied yearly. As yield potential increased, A. fatua competitive effects were more evident and ETs decreased. Nonetheless, both treatment factors increased ETs in 2 of 3 years. These results demonstrate that the use of higher seeding rates and larger seed size classes both improve wheat competitive ability towards A. fatua while simultaneously increasing economic returns.     

Resistance to foliage-feeding insects in conifers: implications for pest management

The ecological implications of insect resistance in conifers are rarely discussed. It is however a fairly straightforward plant-insect interaction and should be treated as such, making use of the increasing amount of information in this field. Work on tree breeding is usually carried out by silviculturalists who, not surprisingly, rarely consider the insect component of the environment in which the treess are growing. In all fairness, it must be stated that many entomologists, fail to consider the plant component of the interaction. Clonal forestry will almost certainly result in the loss of genetic variability. The use of clonal material has already been cited as a possible source for the diminution of the resistance against pests and diseases and if particular resistance mechanisms against forest pests are sought in the future the reduction in genetic material caused by clonal selection could have serious consequences. The ethics of clonal forestry have been questioned as have the ethics of biotechnological advances in the area of recombinant DNA molecules. The potential of both these techniques should be publicized and brought to the attention of the general public and the scientific community at large and evaluated. To improve our forest environment and to protect the environment as a whole, entomologists, geneticists, physiologists and silviculturalists must work together to produce better trees that require little, if any, chemical aid, be it insecticides, herbicides, fungicides or fertilizers. An increasing awareness of the environmental problems generated by large-scale insecticide applications to forest plantations, coupled with an increasingly chemophobic work-force and the difficulty in obtaining pesticide registration for use in forest environments, means that the forest industry world-wide must look to the use of integrated control measures with more diligence than has been shown in the past. Many recent outbreaks of pests and diseases have been linked with particular seed origins of tree crops. Host plant resistance as part of a suite of other proposed integrated control tools is thus an obvious candidate for development. Despite this, scientists concerned with tree improvement continue to select largely for silvicultural traits rather than for resistance to pests and disease. The different avenues open to plant breeders are examined and the potential of breeding trees resistant to insect attack highlighted. Using resistant trees as part of an integrated pest management system has five very important properties. Firstly, there is no additional pest control cost to the grower, secondly, it operates at all levels of insect incidence and not just when the pest is at high population levels, thirdly, it reduces the insect population cumulatively, fourthly it avoids toxic residues and environmental pollution and, finally, it usually interacts well with the other integrated pest management strategies in existence.     

鄂北地区栗瘿蜂综合防治技术研究

栗瘿蜂在鄂北地区一年发生一代，以初龄幼虫在被害芽内越冬。翌年4月上旬栗芽萌动时开始为害，使被害芽形成虫瘿抑制新梢生长，导致减产甚至绝收。当地该瘿蜂优势种天敌是中华长尾小蜂，益害比1∶5时能抑制栗瘿蜂的大发生。以冬季清园铲除杂草，剪除病虫枝等农业防治为基础，收集虫瘿于3月下旬挂于栗园保护天敌为主导，辅之以化学防治的综合防治措施能有效地控制栗瘿蜂的为害。     

新疆果树多毛小蠹生物学特性及防治

多毛小蠹是新疆果树重要害虫，危害杏树甚为严重。在库尔勒一年发生2～3代，主要以幼虫和少数成虫、卵在树皮内越冬，世代重叠。在自然变温下，卵历期4～11天，幼虫20～31天；蛹期6～9天；成虫10～35天。完成一世代需40～86天，主要以幼虫在寄主树表面活动。采用农业和药剂防治相结合效果显著。     

辣椒田蟋蟀种类、生活规律与综合防治的研究

辣椒田蟋蟀有5种。北京油葫芦 Teleogryllus emma Ohmaehi et Matsumura 为陕西关中灌区椒田的主要种。大扁头蟋 Loxoblemmus doenitzi Stein 为不同生态区的常见种。各种蟋蟀在陕西1年均发生1代,以卵越冬,4月下旬孵化盛期,4月下旬—9月上旬若虫发生期,8月下旬—9月下旬成虫发生盛期。8—9月是为害辣椒的关键时期。蟋蟀具有较强的趋光性、趋化性,有趋向于渠边、地边的习性,18—19时为日活动高峰。地膜、杂草孳生、生长势郁闭、麦糠(草)覆盖及混作的椒田,种群数量大,为害严重。早期田间挖窝诱蛛、插种玉水、花生、繁育天敌,中期溜施毒土,后期毒饵诱杀,是控制蟋蟀为害的有效措施。     

中国与欧美农业科技创新体系对比研究

农业科技创新发展已成为推动现代农业发展的重要原动力。近年来,中国步入农业科技创新发展的快车道,为探寻建立健全中国农业科技创新体系的路径与方法,对美国、英国、德国与中国的农业科技创新体系进行对比。结果表明：①农业产业的特殊性决定农业科技创新体系的特殊性,农业科技创新主体、农业科技创新环境、农业科技创新成果与应用、农业科技创新国际合作相互作用,构成完整的农业科技创新体系。②产学研紧密结合是美国农业科技创新体系的突出特点,英国则是注重政府引导、信息共享与知识服务,德国是信息化生态型农业科技创新体系代表,注重信息引领与绿色、可持续发展。③与欧美农业科技创新体系相比,我国农业科技创新体系仍存在一些不足,未来可从协调统筹、规划建设、队伍与机制建设等方面入手,全面推动我国农业科技创新体系发展建设。     

以党的十六大精神为指导,努力创建一流大学

认真学习十六大报告,切实贯彻十六大精神,对建设一流大学起着十分重要的指导作用。一流大学在大学内部表现为追求卓越的目标定位、指标评定,在大学与社会关系中表现为社会的认可。目前,"综合性、研究型、开放式"的办学模式是我国创建一流大学的共同目标。在我国,要建设国际上有影响的一流大学,必须在近几年打下坚实基础。     

黄土高原地区的生态建设与政策创新

生态环境建设是西部大开发的根本切入点。黄土高原地区是我国生态环境最为严峻的地区 ,目前仍有 2 9× 10 4 km2 的土地有待治理 ,任务十分艰巨。本区生态环境建设的主要阻力是生态系统脆弱、经济系统贫困、科技文化水平落后、生态建设效益滞后、投资巨大等。提出的对策是稳定落实“退田还林”补贴政策 ,完善多元化的生态建设投资体系 ,建立公平合理的资源开发政策体系 ,加强生态环境建设的科技支撑作用 ,严格控制人口的快速增长等。强调排除阻力、促进生态环境建设的关键是调整思路 ,在各项政策和措施上都有所创新 ,有所突破     

甜菜丛根病综合防治技术研究Ⅱ.综合防治技术示范

对３个引进品种在不同病害程度条件下示范试验结果表明,在重病绝产地,平均根产量达６７ｔ／ｈｍ＾２,增产３７％～４７０％,Ｂｅｔａ４０３５和Ｂｅｔａ４７７６的含糖率高达１７％以上;在中度病田,平均根产量为８０．９ｔ／ｈｍ＾２,增产２１０％～２６０％,含糖平均在１５．１％;在轻病地,平均根产量高达８７．９ｔ／ｈｍ＾２,增产１５３％～１６０％,含粮率平均为１５．２％。真实地反映了这项综合防治技术的可行性和引进品种的适应性及稳定性,展示了良好的应用前景。