The Anatomy and Chemistry Of “Rubbery” Wood in Apple Var. Lord Lambourne

The anatomy of a one-year-old vertical normal stem of apple var. Lord Lamboume was compared with that of a comparable stem infected with rubbery wood virus and with that of a normal stem caused to undergo an anatomical georeaction by bending it at right angles to the vertical. The stem anatomy of 5-year-old orchard trees showing rubbery wood symptoms was compared with that of comparable normal trees. Staining reactions and investigations using light, polarizing and ultra-violet microscopes, and X-ray diffraction techniques established the anatomical identity of rubbery and georeaction wood.

Rubbery wood resembled georeaction wood in having a lignin content less than that of normal wood. It differed from georeaction wood in that oxidation of its lignin produced a molar ratio of syringaldehyde to vanillin which was less than that from normal wood lignin. Rubbery wood gave a yield of milled wood lignin greater than that of normal wood. This suggests that the lignin of rubbery wood is less firmly bound to the polysaccharide framework. This could account for the greater flexibility of rubbery wood.     

Depressing Effects of Virus Infection on Adventitious Root Production in Apple Hardwood Cuttings

Adventitious rooting in dormant hardwood cuttings of MM. 106 apple rootstock was depressed by latent infection with five viruses, viz. rubbery wood, stem pitting, epinasty and decline, chlorotic leaf spot and platycarpa scaly bark viruses.

Both the number of rooted cuttings and the number of roots per rooted cutting were reduced, and fewer unrooted cuttings remained alive, thus representing a further potential loss.

The production of shoots suitable for use as cuttings was decreased from infected hedges, as was the ability of cuttings subsequently to become established and grow in the nursery.     

Comparing Lignin-Staining Procedures for Detecting Apple Rubbery Wood Virus in Apple cv. Lord Lambourne Trees Under High Summer Temperatures

Stains used to detect incomplete lignification in apple cv. Lord Lambourne when infected with the apple rubbery wood virus (RWV) included gentian violet, methyl red in water or in dilute HC1, and phloroglucinol in concentrated HC1 or in ethanol. Of the five procedures, phloroglucinol in HC1 was preferred. Some staining methods detected RWV infection in Lord Lambourne trees or shoots which did not exhibit the usual weeping symptom; they did not detect virus in other varieties infected with RWV. High summer temperatures did not prevent expression of obvious symptoms in the Lord Lambourne virus indicator with respect to most of the sources or strains of the virus.     

The Effect of ‘Latent’ Virus Infections on the Yield of Maiden Trees on 20 Apomictic Apple Seedling Rootstocks

Five years’ experiments with apomictic apple seedling rootstock selections budded with apple cultivars have shown that incompatibility in Malus sieboldii, M. sargenti, M. hupehensis and their derivatives is mainly due to high sensitivity of the species rootstocks to viruses latent in commercial apple cultivars. The yields of maiden trees from rootstocks which were budded with material that was virus-free, infected with ‘latent’ viruses and infected with ‘latent’ viruses plus rubbery wood virus were 67%, 28% and 16%, respectively. There were, however, differences in the sensitivity reaction between the rootstocks tested. Fairly good compatibility with scions infected with ‘latent’ viruses was observed in the M. sieboldii root- stock selections 4542, 4556 and 4608 and in M. hupehensis.     

香菇木扦原种生产工艺与应用研究

选择材质较硬的木扦制作的木扦原种，生产的栽培种满袋时间仅需锯木屑种的一半，降低了后期感染的机率，成活率高，满袋后菌丝活力旺盛，无老化现象，延长了保藏时间。     

山区林场锯末栽培阿魏菇试验初报

在山区6～9月采用陈旧和新鲜的锯末、木屑与棉籽壳混合配料,研究了锯末、木屑添加量对阿魏菇菌丝生长和出菇量的影响.结果表明:露天堆放半年的锯末与棉籽壳1∶1混合栽培阿魏菇,菌丝生长良好,出菇转化率达到33.5％,而新鲜木屑与棉籽壳1∶1混合栽培阿魏菇,出菇转化率达到13.5％,锯末、木屑添加量超过一半时出菇量下降,单一使用锯末或木屑没能出菇.在山区林场利用当地堆放时间更久的锯末或木屑生产白灵菇是可行的.     

FTIR-ATR-based prediction and modelling of lignin and energy contents reveals independent intra-specific variation of these traits in bioenergy poplars

Background  

There is an increasing demand for renewable resources to replace fossil fuels. However, different applications such as the production of secondary biofuels or combustion for energy production require different wood properties. Therefore, high-throughput methods are needed for rapid screening of wood in large scale samples, e.g., to evaluate the outcome of tree breeding or genetic engineering. In this study, we investigated the intra-specific variability of lignin and energy contents in extractive-free wood of hybrid poplar progenies (Populus trichocarpa × deltoides) and tested if the range was sufficient for the development of quantitative prediction models based on Fourier transform infrared spectroscopy (FTIR). Since lignin is a major energy-bearing compound, we expected that the energy content of wood would be positively correlated with the lignin content.     

Suitability of wood fiber substrate for production of vegetable transplants: I. Physical properties of wood fiber substrates

Several experiments were conducted with the objective to find suitable alternatives for peat substrates. Physical properties of wood fiber substrates in comparison to other organic substrates were examined. Volume weight, total pore space, pore size distribution, available water, container and air capacity, saturated hydraulic conductivity and volume loss of these substrates were determined. Wood fiber substrates showed a similar volume weight and total pore space as peat substrates, but lower water retention. Particularly the drainage performance of wood substrates results in a quick drainage of surplus water. An increase of volume weight caused a decrease of total pore space, air content and saturated hydraulic conductivity and an increase in water retention. Evaluation of these parameters under container conditions is critical since they are directly related to irrigation and therefore to plant growth. A compression of wood fiber substrates in the pots is recommended to minimize substrate loss. An increase of compression levels reduced the volume loss to almost 0 vol.%. The effect of wood fiber substrates and their volume weight on plant growth will be reported in a second paper.     

木塑与钢材复合温室骨架设计及力学性能试验

木塑复合材料是近几年发展较快的一种新型材料,具有易加工、密度高、硬度强的特点。为探究木塑在温室建筑上的应用,设计了一种适合温室使用的木塑与钢材复合骨架,并进行力学性能试验。该试验以木塑和钢材为试材,采用拉伸、压缩、人工气候老化及复合骨架应用于温室的方法,研究了其抗拉、抗压强度及其在温室中应用情况,以期能够开发一种在性能和价格上与钢骨架结构材料相媲美的新材料。结果表明:在低温、室温和高温条件下,木塑的抗拉强度分别为28.391、24.954、15.000 MPa,木塑的抗压强度分别为63.633、42.438、32.547 MPa,木塑的抗拉强度和抗压强度均与环境温度呈负相关关系。木塑在经过250 h的人工气候老化后的抗弯强度为37.040 MPa,比未进行老化处理下降了22.083%。将木塑与钢材结合制作成不同形式的复合骨架,与普通木塑骨架对比,在室温下测试发现复合骨架比普通木塑骨架抗弯性能显著提高,其延展性提高约3倍,其中钢材添加在下缘的复合骨架的抗弯性能显著较钢材在上缘的复合骨架优越;带卡簧卡槽复合骨架的最大抗弯屈服力为19.112 kN,较钢材在下缘的复合骨架提高88.74%,达到了温室骨架的承载力要求。通过供试带卡簧卡槽复合骨架温室的荷载试验得出,跨度8.0 m、顶高3.3 m的拱形屋面温室,其骨架间距为1.2 m时,供试温室承受荷载为0.436 kN·m^-2;当骨架间距为1.0 m时,其承受荷载为0.527 kN·m^-2。与传统钢骨架温室对比,复合骨架温室的建筑成本减少了10.4元·m^-2。该复合骨架可以同时发挥木塑的环保、价廉、可塑性优势和钢材的优良力学性能,为温室建筑的轻简化、装配化提供了有益参考。     

Relationships of dead wood patterns with biophysical characteristics and ownership according to scale in Coastal Oregon,USA

Dead wood patterns and dynamics vary with biophysical factors, disturbance history, ownership, and management practices; the relative importance of these factors is poorly understood, especially at landscape to regional scales. This study examined current dead wood amounts in the Coastal Province of Oregon, USA, at multiple spatial scales. Objectives were to: (1) describe current regional amounts of several characteristics of dead wood; (2) compare dead wood amounts across ownerships; (3) determine the relative importance, according to spatial scale, of biophysical and ownership characteristics, to regional dead wood abundance. Dead wood plot data were evaluated with respect to explanatory variables at four spatial scales of resolution: plots, subwatersheds, watersheds and subbasins. The relationships of dead wood characteristics with biophysical attributes and ownership were diverse and scale-specific. Region-wide dead wood abundance and types varied among ownerships, with public lands typically having higher amounts of dead wood and more large dead wood than private lands. Regression analysis of total dead wood volume indicated that ownership was important at the subbasin scale. Growing season moisture stress was important at plot, subwatershed, and watershed scales. Topography was important at the two coarser scales. Multivariate analysis of dead wood gradients showed that ownership was important at all scales, topography at the subbasin scale, historical vegetation at watershed and subbasin scales, and current vegetation at plot and subwatershed scales. Management for dead wood and related biodiversity at watershed to landscape scales should consider the distinct dynamics of snags and logs, the importance of historical effects, and the relevance of ownership patterns.     

不同基质栽培黑木耳的营养成分分析

对以桑枝屑、梨枝屑、杂木屑为主要基质栽培的黑木耳的常规营养成分、氨基酸、总黄酮、1-脱氧野尻霉素(1-Deoxynojirimycin,1-DNJ)、维生素和微量元素含量等进行检测,探讨不同基质栽培的黑木耳的营养成分之间的差异。结果表明,桑枝屑黑木耳中的总糖、粗纤维、碳水化合物、黄酮、微量元素钙和磷含量较高,梨枝屑黑木耳中氨基酸总量、铁、锌、维生素B1和B2的含量较高,表明桑、梨枝屑可以作为黑木耳栽培的基质加以利用。     

Biology and control of the apple canker fungus Neonectria ditissima (syn. N. galligena) from a Northwestern European perspective

A review of apple canker caused by Neonectria ditissima is presented for Northwestern Europe with a focus on the Lower Elbe region (Northern Germany). Whereas conidia released by rainsplash are produced mainly from spring to autumn, the liberation of wind-borne ascospores peaks in autumn and/or early spring. Infection occurs via natural as well as pruning-induced wounds, some of which are present throughout the year. Autumnal leaf scars are the most frequent entry point for N. ditissima. Wounds on tree trunks, especially bark cracks in the crotch regions, are potentially even more serious because cankers on trunks and leader shoots commonly cause the total loss of a tree. Surface moisture is a prerequisite for leaf scar infections but possibly not for an entry through other wounds. Irrespective of the entry route, successful infection of a wound requires a mass inoculum of at least 50–100 conidia or ascospores. Infections of trees originating in nurseries may enter a state of latency from which they can break out up to 3 years after the trees have been explanted into the production orchard. Streaks of brown wood discolourations can be caused both by systemic colonisation of the xylem by N. ditissima and by winter frost damage. Apple varieties may show pronounced differences in their sensitivity to canker. For highly susceptible varieties, this disease can be a major production-limiting factor. Flower infections by N. ditissima commonly lead to a pre-harvest rot at the blossom end of the fruit, whereas infections of the growing fruit before harvest lead to a storage rot. Rigorous pruning is an essential canker control measure. Chemical control during the growing season is achieved by apple scab fungicides such as dithianone, captan or dodine. At leaf fall and in winter, copper fungicides are indispensible for controlling canker on highly susceptible varieties in Northern Germany.     

Retention of nutrients by peats and wood wastes

The retention and release of major nutrients by New Zealand peats and wood wastes was studied over 24 weeks in an incubation experiment. Irish sphagnum peat was included for comparison. The treatments consisted of fertilized and unfertilized materials. The samples were extracted with water using a 1 : 1.5 (v/v) ratio. Retention of N was low for all peats, but noticeably high for bark and wood shavings after 3 weeks. At 24 weeks, the peats retained less than 20%, while the wood wastes retained 35–68% of the applied N. There was little or no release of N by any material. Retention of P was also low for N.Z. peats (except Cambridge), although not as low as for Irish peat, but again high for bark and wood slavings. Retention of K was higher for peats than for wood wastes. Wood wastes contain more water-soluble K than peat.     

Variation in modulus of elasticity (E) along Acer platanoides L. (Aceraceae) branches

Arborists and managers of amenity trees could benefit from an improved understanding of how tree canopies withstand loading events such as wind, snow or ice. Knowledge of how material properties change along tree branches is important in understanding how a branch tips can bend in the wind yet resist displacement at the base which could lead to branch failure. Limited knowledge of modulus of elasticity (E or stiffness) in branch wood is available in the literature and is typically measured at only one location on a branch. This study investigated variation of E and density-specific E (E/ρ) at five locations along the axis of 20 branches from seven trees. E and E/ρ were found to be 70% lower at the branch tips than in the proximal locations. The variation in E was negatively correlated with the percentage of tissue area composed of vessels and positively correlated with mean fiber cell wall size, suggesting a balance between the two principle functions of hydraulics and mechanics. Reaction wood was observed in the form of gelatinous layers in fibers along the branch tops, but did not result in a difference in E between the top and bottoms at each branch location. It is proposed that differences in material properties are probably related to wood development type, as juvenile wood is considered to have lower stiffness than mature wood.     

Wood age and leaf area influence fruit size and mineral composition of apple fruit

Summary

The influence of wood age, fruiting position and leaf area within the tree canopy on fruit mineral content and quality for several apple (Malus domestica Borkh.) cultivars was investigated. Size and Ca, Mg and K content of individual fruit on one-year (lateral and terminal positions), two-year and older than three-year wood were compared for cvs Royal Gala, Braeburn, Granny Smith and Fuji. Fruit on two-year spurs and one-year terminals was generally larger at commercial harvest than that on one-year laterals and spurs older than three years. Flower receptacles at full bloom were larger and fruit growth rates were greater from 60 to 100 d after full bloom on two-year spurs than on one-year laterals. Fruit Ca and Mg concentrations and contents at commercial harvest were highest for terminal fruit, but there was no consistent difference between fruit from other positions. One-year terminals had the greatest primary and bourse leaf areas, two-year spurs were intermediate and one-year laterals had the lowest areas of both leaf types. Removal of 50% of primary leaves and/or removal of bourse shoots from clusters at bloom reduced fruit Ca content at commercial harvest for two-year spurs, one-year laterals and one-year terminals. Bourse shoot removal also reduced Mg content for all positions. However there was no effect of leaf removal on fruit size or K content. Ca content of individual fruit increased curvilinearly with increasing total spur leaf area for fruit on two-year spurs and one-year terminals but not for fruit on one-year lateral clusters. Terminal fruit with total spur leaf areas and fruit size similar to those on two-year spur fruit had higher Ca content.     

壳聚糖的木酢液对黄瓜生长与产量及品质的影响

试验分别选用木酢和乙酸溶解壳聚糖处理温室土壤,研究对黄瓜生长、产量及品质的影响,并进行了效益分析。结果表明:与对照相比,木酢和乙酸溶解壳聚糖处理温室土壤均能促进温室黄瓜的生长,提高其产量,改善其品质;黄瓜产量随着木酢液中壳聚糖浓度的增加有显著的提高,而随着乙酸溶解壳聚糖处理浓度的增加,黄瓜产量没有明显的变化;木酢溶解壳聚糖处理土壤对黄瓜的影响与乙酸溶解壳聚糖处理土壤对黄瓜的影响之间差异不明显;使用木酢作壳聚糖的溶剂效益要好于乙酸。     

利用抚育间伐木材栽培黑木耳

为充分利用抚育间伐的木材资源,提高山区农民的收入水平,总结出了一套利用抚育间伐木材进行黑木耳段木栽培的高产技术,包括栽培季节安排、品种选择、出耳场地选择、菌种准备、树种选择及砍伐、木材处理、钻孔接种、发菌管理、起架排场、采收、晾晒、分级、包装等环节,同时建议将黑木耳段木栽培与休闲农业相结合,不仅可为山区农民增加收入来源,还能实现山区林木资源的高效利用,取得良好的社会、经济及生态效益。     

木醋液作灌根对番茄生长发育和产量的影响

利用不同浓度的木醋液对番茄进行灌根施肥,研究木醋液灌根对番茄生长发育和产量的影响。结果表明:木醋液灌根施肥能提高番茄的株高、茎粗、单果重和产量,其中稀释1 000倍的木醋液灌根可提高番茄产量22.43%,在保护地施肥中可以大力推广。     

A computer-based tool to link decay information to 3D architecture of urban trees

We present a software application suitable for studies of the decay in trees. The application implements the storage of measurements of stem characteristics (related to decay) and visualization of the three-dimensional (3D) structural model of tree stems and branches built using this material. The application has been constructed on the basis of an existing architectural model of trees. A set of photographs taken from discs cut from felled trees works as the input for the application. The user will define, using the application, the contours of the areas of interest (e.g. healthy wood, decayed wood and cavity) manually in the photographs of stem or branch cross sections. The application then builds a 3D structural model of stem and/or branches on the basis of the input. It is possible to study visually the composition of the stem and/or branches of different types of wood. This helps to evaluate the location of potential hazard and its relation to existing damage in tree stems and branches.     

Needle disinfection and bioptic wood sampling achieved with a disposable for drill resistance measurement devices

Needle drill resistance measurement devices (NDRMDs) are often used during tree hazard assessment campaigns to detect and measure the extent of wood decay and other defects of wood in trees, despite of the possibility of transmission of potentially pathogenic microbial inoculum from tree to tree through unclean needles. Here, we describe a disposable connectable to NDRMDs through an adapter and we report on its efficacy not only at disinfecting the needle, thus reducing the likelihood of disease transmission, but also at collecting wood samples for bioptic purposes, whose subsequent analysis may be pivotal for, or allow to refine, the prognosis. The complete efficacy of the disposable at disinfecting the needle was determined through three different experiments conducted under controlled conditions in vitro and in vivo using both wood decay fungi and the canker stain pathogen of plane trees, and under field conditions. The disposable combined with NDRMD proved to be as effective as state-of-the-art drilling methods at collecting wood samples for subsequent PCR-based molecular diagnosis of wood decay fungi (Fisher’s exact test for count data; P = 4.846 × 10⁻⁷) as determined through comparative sampling and diagnostic assays on 42 trees. The disposable allows not only for a routinely, complete and fully standardized disinfection of the needle, but also provides the opportunity to automatically and efficiently collect bioptic wood samples for subsequent phytopathological analyses.