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1.
冻害是陕西花椒产业发展中存在的突出问题之一。根据花椒冻害发生的特点和受冻程度,提出了冻害等级划分为5级,花椒冬季冻害和春季冻害调查方法、评价指标及其分值、综合评价标准,花椒冬季冻害和春季"倒春寒"预防技术及冻害补救措施。  相似文献   

2.
碧护对花椒晚霜冻害及生长结果的影响   总被引:2,自引:2,他引:0  
试验了喷洒不同浓度、不同时期喷施碧护后,花椒冻害程度和新梢生长量、千粒质量、麻香味等的变化。结果表明,碧护在有效预防和缓解低温冻害的同时,显著提高了花椒产量和品质,可促使花椒叶片厚而浓绿,光合作用明显提高,减轻了花椒缺素症状,增强了花椒的抗逆性。  相似文献   

3.
陕西花椒冻害的发生现状及防治对策   总被引:2,自引:1,他引:1  
花椒是重要的香料、油料及水土保持树种 ,陕西省主要分布在凤县、韩城、富平、澄城等地 ,在许多地区已经形成规模 ,成为广大群众发家致富的拳头产品。近年来 ,春季花椒开花期常出现霜冻危害 ,加之广大群众对花椒霜冻害的认识不够 ,没有采取积极的预防措施 ,造成花椒大面积受害 ,轻者枝梢冻死 ,重者枝干皮层出现冻裂 ,甚至枯死 ,造成花椒严重减产 ,经济效益低下 ,极大地挫伤了广大椒农的生产积极性 ,影响了发展花椒的产业化进程。因此 ,加强花椒的科学管理 ,积极预防霜冻害 ,成为花椒丰产栽培措施中的重要内容。1 花椒冻害发生现状及特点1 .…  相似文献   

4.
凤县花椒寒害的调查研究   总被引:4,自引:3,他引:1  
花椒具有生长快、收益大、栽培管理方便等特点,越来越成为山区脱贫致富奔小康的理想树种。然而,冻害问题一直是困扰花椒产业发展的难题。为此,针对凤县花椒寒害进行了调查,该县的回寒型霜冻害发生频率较高。大规模的冻害大约每10年1次,小规模的冻害隔年发生;局部冻害主要为枝干日灼。结合当地实际情况,提出了花椒寒害的类型和特点,旨在为花椒寒害的预防提供理论依据。  相似文献   

5.
<正> 近几年来,随着农村产业化结构的调整,花椒栽培面积在渭北旱塬发展很快,一个全国规模最大的优质花椒生产基地在陕西省渭北旱塬已初步形成,但是由于渭北旱塬的冬春两季气候变化异常,易使花椒树体和花芽遭受冷冻底温的严重危害,若不及时进行人工预防,会造成花椒果实的大幅减产。因此,在花椒生产中应抓好以下几项预防冻害的有效措施。  相似文献   

6.
本文对凤县花椒霜冻的预防方法进行了研究.结果认为,花椒霜冻受地形影响较大,凤县花椒种植应合理化建园,避开局地气候影响,椒园建在霜冻灾害较轻地域,兼用各种方法,改善局地小气候,减小花椒冻害.对已造成冻害的椒园在补救方法上也做了总结.  相似文献   

7.
花椒冻害的原因及防治措施   总被引:3,自引:0,他引:3  
花椒冻害的原因及防治措施张润昌,田玉堂,白书太(涉县林业局)花椒适应性强,抗干旱,耐瘠薄,是我国华北、西北、西南广大山区栽培的重要经济树种。在冬春季节,常使花椒受冻,损失很大。因而,花椒冻害的预防,是花椒栽培中一项十分重要的工作。1冻害的原因气象条件...  相似文献   

8.
在我国北方花椒产区,冬春季节的异常气候,常使花椒受冻,造成严重为害,损失很大。因此,花椒冻害的预防,是花椒栽培中一项十分重要的工作。  相似文献   

9.
花椒是渭南市主要经济林树种之一,栽培面积广。土肥管理不到位、整形修剪不力、病虫危害严重、冻害和落花落果严重及栽植密度过大等因素是造成花椒低产低效的主要原因。从加强土肥水管理、重视整形修剪、病虫害和冻害的预防防治、科学间伐等方面提出了具体的综合改造技术措施,对渭南花椒提质增效具有一定的指导作用。  相似文献   

10.
采用不同浓度的青鲜素在花椒(Zanthoxylum bungeanum Maxim.)树上喷施,观测花椒萌芽期、测定花椒新梢生长量。实验结果表明,花椒树喷施青鲜素最适宜的浓度为1 000mg/L,对花椒新梢生长量影响不大,而对花椒萌芽期有明显延迟作用,为探索研究花椒萌芽期有效避开晚霜发生期、系统预防花椒晚霜冻害以启示和新的技术途径。  相似文献   

11.
This study investigated the dynamic modulus of elasticity (DMOE) of wood panels of Fraxinus mandshurica, Pinus koraiensis, and Juglans mandshurica using the natural frequency measurement system of fast Fourier transform (FFT). The results were compared with the static modulus of elasticity (E S) tested by a mechanical test machine. The results show a significant correlation between E S, transverse vibration DMOE (E F), and longitudinal vibration DMOE (E L). For all of these species, the correlation between E S, E F and E L is more significant than the individual species, which indicated that the FFT method is universal. The correlations between E S and sample’s density (ρ) are significant, but the correlation coefficient of E S and ρ is lower than those between E F, E L and E S. The E S of wood is more accurately tested by the analysis based on FFT measurement than by the estimation based on density. __________ Translated from Scientia Silvae Sinicae, 2005, 41(6): 126–131 [译自: 林业科学, 2005, 41(6): 126–131]  相似文献   

12.
Bacterial blight is considered one of the most serious diseases affecting the genus Juglans. Artificial inoculations with Xanthomonas campestris pv. Juglandis were performed in the field by spraying seedlings of Juglans cinerea, Juglans hindsii, Juglans mandshurica, Juglans nigra, Juglans regia and Juglans sieboldiana. Juglans nigra, J. cinerea ana J. sieboldiana proved to be the most resistant. The multiplication ability of Xanthomonas campestris pv. corylina, X. c. pv. juglandis, and X. c. pv. campestris was evaluated by injecting 2-year-old seedling leaves of J. mandshurica, J. nigra and J. regia. The bacterial growth was monitored in the infected tissue over 12 days. Xanthomonas c. pv. juglandis exhibited a high growth rate and induced black greasy spots in J. mandshurica and J. regia; X. c. pv. campestris grew in leaf tissues without inducing symptoms, X. c. pv. corylina showed a very low growth rate. None of the tested bacterial strains multiplied in the leaves of J. nigra. This confirms the results obtained in the field tests. Juglans regia was the most susceptible among the walnut species tested.  相似文献   

13.
The effects of flooding on growth of seedlings were compared over a 7-month period (April–November) among six different woody species: Aesculus turbinata, Cercidiphyllum japonicum, Fraxinus platypoda, Pterocarya rhoifolia, Pterostyrax hispida, and Quercus mongolica var. grosseserrata. Flooding reduced the shoot length of F. platypoda, P. rhoifolia, C. japonicum, P. hispida, and Q. mongolica var. grosseserrata seedlings but did not affect that of A. turbinata seedlings. Among control seedlings, shoot elongation occurred once in A. turbinata and twice in F. platypoda and Q. mongolica var. grosseserrata; the other species continued to grow from April to August. Among the flooded plants of all species, shoot elongation occurred only once at the beginning of the growing season. On August 25, flooding significantly reduced the number of developed leaves as compared with control plants except for A. turbinata. In the flooded plants except for F. platypoda, leaf fall began on June 30; in controls, by contrast, the number of developed leaves increased until August 25. Flooding reduced the total dry weight increment in all species. The survival ratio of flooded plants after the experiment differed with species. All of the F. platypoda and A. turbinata seedlings survived the flooding treatment, while only 20% of P. hispida and 30% of Q. mongolica var. grosseserrata survived. Flooding seriously affected the growth of riparian pioneer species including P. rhoifolia, C. japonicum, P. hispida, and Q. mongolica var. grosseserrata. The effects of flooding on growth of the seedlings differed with the tree species because of differences in leaf-emergence pattern and physiological flood tolerance. The responses of tree seedlings to flooding reflected species habitats and growth patterns.  相似文献   

14.
The mechanical strength properties of the branchwood of Aningeria robusta and Terminalia ivorensis with diameters ranging from 10 to 25 cm were examined to determine the suitability of branchwood as raw material for downstream processing. The study precisely assessed the static bending strengths, compression strengths and shear strengths parallel to the grain of the branchwood and stemwood of T. ivorensis and A. robusta. It was observed that under static bending, the overall (sapwood and heartwood combined) modulus of rupture and modulus of elasticity of the branchwood of A. robusta and T. ivorensis were lower than that of their corresponding stemwood. The results further show that the overall compression and shear strengths parallel to the grain of the branchwood of A. robusta and T. ivorensis were higher than that of their corresponding stemwood. Under static bending, compression parallel to the grain, and shear parallel to the grain, the experimental results indicate that the sapwood of the branchwood from both T. ivorensis and A. robusta had lower strength values than that of their corresponding heartwood. Similar results were recorded for the stemwood of T. ivorensis where the heartwood had higher strength values than the sapwood. However, in the case of the stemwood of A. robusta, the sapwood had higher strength values than the corresponding heartwood.  相似文献   

15.
正林木90%以上的干物质来自光合作用,单位时间内光能利用效率(包括光能截获能力和光能转化效率)是衡量林木生长潜力的重要指标。光能截获能力主要与叶面积大小及其发展有关,光能转化效率主要与单叶光合速率有关。自发现光合速率在不同个体间存在明显差异后,以提高光能利用效率为目标的"高光效育种"受到育种学家的重视[1-3],而通过选配高光效种质进行有目的杂交已成为高光效育种的重要手段[4]。落叶松(Larix spp.)种间杂交  相似文献   

16.
The poplar bacterial canker caused by Erwinia sp is a serious disease spreading inmost parts of Northeast China,where poplars are cultivalted.The disease seriously infects thosepoplars belonging to section Aigeiros or the intersection hybrids of section Tacamahaca and section Aigeiros and their clones.Five fine poplar cultivars resistant to the bacterial canker have been ob-tained by screening tests.They are Lz_2(Populus simonii×nigra var.italica),A_(15)(P.×sp.)613(P.×sp.),A_(102)and A_(98)(P.simonii×sp.)T following chemicals are obviously effective,such as:50%DT germicide ,40% XF-136 and 10% C.C.M.A.or 12.5% ramphencol and 50,000 ppm/mlvalidamycin,with which the stems or roots can be watered.  相似文献   

17.
Four regions of chloroplast DNA were sequenced as a prospective genetic marker to identify Japanese representatives of Cyclobalanopsis: Quercus acuta, Q. sessilifolia, Q. salicina, Q. myrsinaefolia, Q. glauca, and Q. gilva. We found that Q. gilva was distinguished from other species based on both the trnL-trnF and trnT-trnL intergenic spacers. The evidence shows good coincidence with the fact that Q. gilva has several peculiar morphological features distinguishable from those of other species. There was no difference in trnL intron and matK. Both trnT-trnL and trnL-trnF intergenic spacers are capable of being used as genetic markers to identify Q. gilva among Cyclobalanopsis species.Part of this paper was presented at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 3–5, 1998  相似文献   

18.
晚松悬浮细胞系的建立和原生质体的分离   总被引:6,自引:2,他引:6       下载免费PDF全文
植物悬浮细胞系的建立和原生质体的分离已被广泛地应用于生理学、生物化学、细胞学、遗传学及分子生物学的研究 ,它是生物技术中进行原生质体培养、杂交、基因转移、突变系筛选等项研究的较理想手段[1] 。针叶树在这方面的研究起步虽晚 ,但至今已取得令人瞩目的进展[2 ] 。晚松  相似文献   

19.
Micromorphology of the bacterial attack of wood   总被引:1,自引:0,他引:1  
Summary This paper describes fully the various patterns of bacterial attack to be observed in wood. It is based on many observations made with bacterially infected wood, both in pure laboratory cultures and in naturally attacked wood from diverse environments. Patterns of attack are described for tracheids, fibres, vessles and rays and three types of pit border decay are figured, together with attack of the pit margo and torus. A brief section also deals with the macroscopic appearances of wood subject to bacterial attack.
Zusammenfassung Auf Grund zahlreicher Versuche und Beobachtungen werden die verschiedenen Formen bakteriellen Befalles von Holz, sowohl bei inokulierten Laborkulturen als auch bei natürlich infizierten Hölzern von verschiedenen Waldstandorten, eingehend beschrieben.Im einzelnen umfassen die geschilderten Befallsformen diejenigen, von denen Tracheiden, Fasern, Gefäße und markstrahlen betroffen werden; außerdem werden drei Typen von Tüpfelwulstfäule, sowie je ein Fall von Bakterienbefall eines Tüpfelhofes und einer Tüpfelschließhaut dargestellt.Dem makroskopischen Aussehen bakterienbefallener Hölzer wird ein kurzer Abschnitt gewidmet.
  相似文献   

20.
[目的]分离并量化土壤自养呼吸和异养呼吸,探讨各自贡献率及其随季节变化的动态特征。[方法]采用壕沟法和气体红外分析法,研究黄河小浪底库区山地栓皮栎人工林土壤总呼吸、自养呼吸和异养呼吸速率的季节动态变化、贡献率和环境影响因子。[结果]表明:栓皮栎人工林总土壤呼吸、自养呼吸和异养呼吸均呈夏季速率高、冬季速率低。栓皮栎土壤总呼吸、自养呼吸及异养呼吸速率与5 cm土壤温度均呈极显著指数相关,温度敏感性系数Q_(10)值大小为自养呼吸(3.40)异养呼吸(2.90)土壤总呼吸(2.45);栓皮栎土壤总呼吸、自养呼吸、异养呼吸速率与0 10 cm土壤体积含水量均显著线性相关;土壤总呼吸、自养呼吸速率与0 10 cm土壤电导率显著相关。土壤总呼吸和异养呼吸的温度敏感系数Q_(10)值均在冬季最大,夏秋季最小;而自养呼吸的Q_(10)值则呈相反的变化趋势。栓皮栎人工林自养呼吸和异养呼吸对土壤总呼吸的月贡献率为13.23%37.33%和62.67%86.76%,且自养呼吸的贡献率与土壤温度的季节变化规律相似。土壤总呼吸、异养呼吸与自养呼吸的CO2年通量分别为1 616.41、1 199.39、417.02 g·m~(-2)·a~(-1)。[结论]经过区分与定量化土壤总呼吸及其组分,确定异养呼吸为本研究区栓皮栎人工林土壤总呼吸的主要组分,作用于异养呼吸的生物与非生物因子均能显著影响整个森林生态系统表层CO_2总排放通量的大小,进一步为该研究区森林生态系统碳循环与能量流动的进一步量化研究提供参考。  相似文献   

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