棕榈藤组培苗移植技术研究

本文研究了黄藤、短叶省藤、单叶省藤、白藤和异株藤组培苗的移植技术。结果显示：试管苗的质量是移植成活与否的关键，适宜的组培苗移植规格为：苗高大于４．０ｃｍ根长大于４．０ｃｍ，带须根；珍珠岩为最优移植介质，移植组培苗的根系生长量大、净 条烽多、成活率最高，分别达２６．１ｃｍ／株、０．８条／株、９５．０％；泥炭土和细沙中选介质，移植成活率〉９０％；最佳的练苗介质配比为４０％泥炭土＋６０％黄心土，移植成活     

甜大节竹丰产栽培试验研究

设计甜大节竹不同时间、不同材料育苗试验和不同造林密度(间种农作物)对比试验研究,经过近8年试验观测,结果是用截杆留鞭育苗,原产地成活率83.3%,引种育苗试验成活率64.2%;采用3m×3m造林密度,栽竹2a,出笋率90.4%,栽竹5a,鲜笋产量365.6kg/667m2。     

Performance of ponderosa pine seedlings under four herbicide regimes in northeast Oregon

The herbicide, hexazinone, was applied four ways over ponderosa pine, 2–0 seedlings planted in northeast Oregon. The four treatments were two broadcast applications, a single broadcast application, a large spot application, and a small spot application. Seedling survival and growth were monitored for five growing seasons. Results indicate that survival more than doubled with either large or small spot applications compared to no application, and either one or two broadcast applications can increase survival an additional 30% over spot applications. Differences in stem volume were substantial, with two broadcast applications yielding more than twice the volume of a single broadcast treatment and more than five times the volume of seedlings treated with spot applications. Trees in small spots were still three times bigger than surviving seedlings in the control. These results are consistent with the concept of competition threshold. Management implications were considered in terms of cost of established seedlings. Although broadcast applications cost more per acre than spot applications, gains in seedling survival, growth and quality offset the additional cost and translate into lower established seedling costs. The cost effectiveness of broadcast applications also may be seen in the elimination of replanting or in-planting requirements and increases in long-term growth potential of the established trees.     

Afforestation trials with Prosopis chilensis (Mol.) Stuntz and Prosopis flexuosa D.C. in the Dry Chaco, Argentina

In implantation trials carried out with Prosopis chilensis and Prosopis flexuosa, the following variables were considered: implantation time (December and March), implantation technique (direct seeding and seedling transplantation) and age of the seedlings at the time of transplantation (60, 105 and 150 days). Survival was evaluated for more than 9 months after implantation and trials were repeated in 3 consecutive years.

Results from both species were similar and they show that survival after transplantation was higher (60–80%) than from direct seeding (35–45%). Survival from transplantation was independent of the size and age of the seedlings and it was less affected by climatic conditions than direct field sowing. Survival from direct seeding was higher in March than in December. The best time for either implantation alternative would be the end of the summer or beginning of fall, when climatic conditions increase the probability of seedling survival.     

进城大树成活率低的原因分析及对策研究

大树引入城市是改变城市生态环境、提高城市绿化绿地质量、生态效益和景观的有效途径。本文分析了进城大树成活率低的原因，提出了提高大树成活率的对策。     

板栗秋末嫁接时的适宜气温

用当年育秧移栽的实生苗为砧木，在１０月３日～１３日进行就地单芽嫁接．嫁接的气温２８～１８℃之同．当年１２月３０日检查，接口愈合且接芽饱满的达９６％，第２年５月２０日检查，抽芽率８８．２％．     

洪泽湖大堤旱柳防浪林更新的问题与对策

本研究从１９９０年开始对洪泽湖大堤迎湖面林台上新植的插干旱柳的生长进行了观察，对洪泽湖大堤的小气候因子、土壤因子进行了测定，分析了这些自然条件与柳树生长的关系以及病虫害、栽培技术对柳树生长的影响，从而明确了影响柳树成活的原因。针对柳树死因，设计了４种栽植方式并进行比较试验，优选出可以大幅度提高柳树更新成活率的最佳栽植方式，提出了提高柳树成活率的一套栽培技术措施。     

呼包高速公路侧柏苗木栽植埋深与苗木成活率的研究

呼包高速公路上栽植侧柏,其成活受水分和栽植埋深多种因素的共同影响。研究表明:在排除苗木质量问题、解决水分等因素影响外,苗木栽植埋深与苗木成活率呈显著的负相关。呼包高速公路中央分隔带侧柏栽植成活的适宜深度为0~10 cm。     

温度、补充营养和体型大小对白蛾周氏啮小蜂成虫寿命的影响

寄生蜂成虫能否找到并寄生足够的寄主,是实现其最大生殖力的重要限制性因素之一[1],该因素与寿命直接相关,故寿命在进化中受到较大的自然选择压力,从而成为寄生蜂重要的适应性特征之一[2];在害虫生物防治实践中,寿命是决定寄生蜂控制寄主害虫能力的重要参数,是常用的评价天敌     

几种造纸用丛生竹秆节育苗试验

在福建省邵武市对椽竹、孝顺竹、坭竹等几种造纸用丛生竹进行秆节育苗试验表明，用平埋方法育苗显著优于斜埋和直插，竹蔸平埋效果更佳；不同竹种秆节育苗成活率存在明显差异；不同年龄的秆节育苗成活率在不同竹种间表现不同；不同育苗时间（３月或５月）的成活率差异不显著。竹秆不同粗细、不同部位、单节段或双节段育苗对比试验，结果以细秆（胸径２．５ｃｍ）、上部节段、双节段育苗成活率较粗秆（胸径４．６ｃｍ）、下部节段、单节段的为高。椽竹秆节径用不同激素处理后，处理间成苗率差异显著，以２，４－Ｄ２０ｍｇ／ｋｇ处理５ｈ和硼酸２０ｍｇ／ｋｇ处理２４ｈ的效果最佳。几种造纸用丛生竹秆节育苗试验＊张文燕周道三马乃训叶长青曹德友张华明