不同冬季修剪方法对桃树果实生长、产量及品质的影响

连续３年对庆丰和燕红桃树进行研究,结果表明,与传统短枝修剪技术相比较,长枝修剪后,树体丰产性能好、产量高,果实着色好,且在大多数情况下,果实可溶性固形物含量高,提高了品质。长枝修剪对果实生长的影响与品种的成熟期有关,早熟品种庆丰无显著作用,晚熟品种燕红采收时平均果重显著增加。采用长枝修剪技术,能显著地提高花芽的质量,尤其是枝条下部的花芽质量,从而可增强对晚霜冻害的抵抗能力,还对在长枝修剪条件下树体保留一年生枝的长度和姿势与果实大小的关系进行了研究,并对长枝修剪早果、丰产、稳产和优质的生物学基础和果园管理特点进行了讨论表示处理间存在Ｐ＝０．０１差异水平。２．２开花物候期修剪方式对树体初花期及花期待续时间无影响。１９９４年,长枝修剪和短枝修剪的庆丰、燕红的花期分别均为４月１４～１８日和４月１４～１９日。但是,开花动态在处理间存在差别。在初花期（４月１４日和１５日）长枝修剪树花朵开放率显著地高于短枝修剪树。另外,长枝修剪处理树体之间开花较整齐（变异系数小）。２．３坐果和产量１９９３年花期连续低温,经观察短枝修剪早久保和大久保受到严重冻害,坐果率低,负载量严重不足,而长枝修剪树对低温抵抗力强,坐果率显著高,从而获得?     

Coincidences between different landscape ecological zones and growth forms of Cembran pine (Pinus cembra L.) in subalpine habitats of the Central Alps

The forgotten depots of the European Nutcracker (Nucifraga c. caryocatactes) often lead to the development of tufts of Pinus cembra. In many cases the other individuals of such tufts are not suppressed by the fittest one, rather there is an intraspecific coexistence up to the senescent stage of the trees. There are fusions of separate trunks, and so frequently the individual history of older trees can only be reconstructed by studying sutures, crown structures or trunk cross sections. Different types of trunk fusions are worked out. By means of transect counting the occurrence of these multiple trunk trees is documented quantitatively in different landscape ecological zones of the Engadin region (the Grisons, Switzerland). The data base is 3024 counted microsites of Pinus cembra individuals arising from seeds, including 5272 living individuals. These multiple trunk trees significantly play an important role in the landscape ecological zones of recent glacier recession and at the alpine timberline. Their growth forms have a higher biomechanical stability.     

武陵山地区野生果树种质资源及其开发利用

调查了地处湘鄂渝黔四省边区的武陵山地区的野生果树种质资源及其开发利用现状。记录到该地区野生果树48科,109属,342种(变种、变型),其中16种为武陵山地区特有的野生果树。含15种以上的科有蔷薇科、壳斗科、猕猴桃科、芸香科、桑科5个科,为该地区野生果树的优势科。介绍了70种具有重要经济价值的野生果树。武陵山区的野果资源已得到初步开发利用,猕猴桃等数种野果已进入产业化阶段。提出了进一步开发利用和保护野生果树资源的策略。     

果树基因工程研究的现状与展望

利用植物基因工程进行果树遗传改良是一个新的研究领域．研究进展较大，并在10多种果树上获得了转基因植株。本文综述了近年来果树基因工程所取得的进展。但要通过基园工程使果树品种改良走向实用化，还应在提高转化率和植株再生率、果树主要农艺性状遗传分析及转基因的表达和调控等方面作进一步深入研究。     

Environmentally sustainable production of food,feed and fuel from natural resources in the tropics

Responding to the challenges posed by global warming, peak oil and biofuels will require a paradigm shift in the practice of agriculture and in the role of live stock within the farming system. Farming systems should aim at maximizing plant biomass production from locally available diversified resources, processing of the biomass on farm to provide food, feed and energy and recycling of all waste materials. The approach that is the subject of this paper is that the generation of electricity can be a by-product of food/feed production. The concept is the fractionation of biomass into inedible cell wall material that can be converted to an inflammable gas by gasification, the gas in turn being the source of fuel for internal combustion engines driving electrical generators. The cell contents and related structures such as tree leaves are used as human food or animal feed. As well as providing food and feed the model is highly appropriate for decentralized small scale production of electricity in rural areas. It also offers opportunities for sequestration of carbon in the form of biochar the solid residue remaining after gasification of the biomass.     

"大树"移植工程技术管理的实践与思考

通过近几年来大树移植工程的实践,在常绿大树移植和落叶裸根大树移植过程中,摸索出一套成熟的技术管理经验。移植的大树要尽可能来源于苗圃,严禁以牺牲自然资源为代价,直接从自然环境中挖取野生大树。     

城市行道树绿化探讨——以郑州市为例

阐述了城市行道树选择的原则及标准.全面调查了郑州市区的行道树绿化,在对应用现状进行分析的基础上,提出了改变当前现状,丰富城市行道树种的对策和建议.     

福建倷树病害调查初报

根据１９８８－１９９３年的系统调查，明确了福建树病害有１６种，其中真菌性病害１１种、细菌性病害２种，线虫病害１种，病因未明的２种．本文描述了１６种病害的症状、病原物、发生及分布情况．     

福建樟叶个木虱初步研究

樟叶个木虱是福建省樟树的重要害虫，该虫在福建一年发生一代或２代，以若虫越冬，越冬若虫于翌年３月上旬开始羽化，３月下旬卵孵化，若虫共５龄，应用氧化乐果和辛硫磷等农药对若虫有良好的防治效果．     

雅安城区行道树现状及发展建议

对雅安市雨城区的行道树进行了调查与评价。结果表明,雅安市城区行道树存在着布局不够合理,树种较单一,基调树种不够丰富,树种选择和管理尚待完善等问题。并提出了进一步提高雅安城区城市道路绿化质量的规划建议。