Physical properties of media for container-grown crops. I. New Zealand peats and wood wastes

Physical properties of New Zealand peats from 5 sources and of wood wastes, bark and sawdust were evaluated in relation to container-grown crops. For comparative purposes, Irish peat was included. All the peats had adequate air space (AS), but the Springhill peat and New Zealand Forest Service bark and sawdust had a particularly high AS (35–38%). Easily available water (EAW) was also adequate in all peats. New Zealand Forest Service bark and sawdust had inadequate easily available water (EAW, 10–12%), but grinding the bark increased this property. All the peats had similar water-buffering capacity (WBC) with the Irish peat having the highest value. The wood waste materials had inadequate WBC. Total porosity was generally adequate in all materials studied and was highest in Springhill peat. The bulk density (BD) was closely related to degree of decomposition (r = 0.95***) and also inversely related to AS and total porosity (r = −0.82* and r = −0.65, respectively).     

枣树嫩枝扦插育苗

介绍了枣枝扦插育苗的基本技术。扦插床铺放15cm厚的按1：1混合的河沙和煤渣。5月至8月采集当年生半木质化的枣头、永久性二次枝和枣吊做插穗，采用人工喷水或自动喷雾装置控制温度和湿度，生根率可达75%-94%。     

MA加天然保鲜剂对红富士苹果的保鲜效果

2004~2005进行了红富士苹果贮藏保鲜试验。结果表明,红富士苹果在0.5%NPS多糖、0.5%NPS多糖与天然抗菌剂1∶1混合液中浸蘸后,放入0.03mm厚聚乙烯袋中贮藏,可有效地抑制果实呼吸强度,推迟呼吸高峰的出现,减少水分散失和腐烂,提高商品性。     

Uptake of nutrients by banana at the 8th- and 19th-leaf stage

Uniform 2-leaved suckers of dwarf banana ‘Cavendish’ (Musa cavendishii) were treated with 2 doses and 2 frequencies of irrigation as main treatments, and 5 combinations of NPK as sub-treatments. Observations of the plants' response to these treatments were made at the 8th- and 19th-leaf stage. Irrigation at fortnightly or monthly intervals in combination with applications of NPK improved plant morphology. P uptake increased with frequent high irrigation and a high level of P application. With low but frequent irrigation, K and Ca uptake increased with high K application and balanced NPK application, respectively. N uptake with a high application of NPK or N increased at the 8th-leaf stage with frequent irrigation at both levels, and increased at the 19th-leaf stage at low level, less frequent irrigation. The leaves contained the highest quantity of N, followed by the petiole.     

Ancient experiments: forest biodiversity and soil nutrients enhanced by Native American middens

The legacy of ancient human practices can affect the diversity and structure of modern ecosystems. Here, we examined how prehistoric refuse dumps (“middens”) impacted soil chemistry and plant community composition in forests along the Chesapeake Bay by collecting vegetational and soil nutrient data. The centuries- to millennia-old shell middens had elevated soil nutrients compared to adjacent sites, greater vegetative cover, especially of herb and grass species, and higher species richness. Not only are middens important archaeological resources, they also offer a remarkable opportunity to test ecological hypotheses about nutrient addition over very long time scales. We found no evidence, for example, that elevated nutrients enhanced invasion by non-native species as predicted by the fluctuating resource hypothesis. However, we did find that elevated nutrients shifted community structure from woody species to herbaceous species, as predicted by the structural carbon-nutrient hypothesis. These results highlight the long-lasting effects that humans can have on abiotic and biotic properties of the natural environment, and suggest the potential for modern patterns of species’ distributions and abundances to reflect ancient human activities.     

圆铃枣嫩枝扦插繁育技术研究

用圆铃枣当年生枣头的先端部分做插条 ,1 5～ 1 7cm厚的上沙下土为插床基质 ,插床上罩拱棚。插前用 5 0～ 1 0 0mg/L的ABT 1号生根粉速蘸 3 0秒 ,插后每天喷雾补水 5～ 1 0次。结果插条生根率 85 %以上 ,根系短而多 ,移栽成活率 97%。用NAA处理插条 ,要用 40 0mg/L的稀释液 ,至少浸泡 2小时以上再扦插。     

苹果实生树叶片中营养元素的含量及其相关性

以苹果杂种实生树的叶片为试材，通过叶分析，明确了不同营养元素的含量及相关性。表明在栽培条件一致、树体生长发育正常的情况下，叶片中的同种营养元素含量差异很大；同一品种的苹果树中不同营养元素含量也有很大差异；各种元素间表现有拮抗作用或协同作用。     

分段芽接扦插繁育甜樱桃苗的技术

利用腾县大红樱桃实生苗或扦插苗，每株选留2－3条功干，于9月下旬至10月初采用带木质芽接法在苗干上每20cm嫁接1个品种芽。嫁接当年落叶后将其整条剪下，经冬季沟藏后翌年3月上旬剪成每段带1个品种芽的插条，用电热毯催根后扦插。按此法繁育成苗率达96．1％，提高繁殖系数5倍以上，一级苗率达96％以上。     

枣树绿枝嫁接法

利用枣树尚未木质化的发育枝作接穗嫁接 ,操作方便 ,易成活 ,成苗快。笔者近年用此法既提高了嫁接成活率 ,又节省了接穗。嫁接适期 :5月中下旬至 7月中下旬 ,砧木与接穗均处于半木质化时为宜。接穗采集 :选取当年生半木质化的发育枝 ,剪后立即摘除全部叶片 ,并把基部浸入水中 ,以防失水抽干。接穗最好随采随用。嫁接方法 :嫁接部位选砧木基部以上 6～ 7ｃｍ、径粗 0 .5ｃｍ以上的枝条光滑处 ,接口以下保留 3～ 5片叶或 1～ 2个小分枝。截断砧木 ,削平截面 ,从截面中间用快刀劈深 3～ 5ｃｍ的切口 (劈接 )。然后将带一主芽的接穗削成一面稍厚…     

杏叶片矿质营养研究进展

杏是我国最古老的栽培果树之一,杏花败育造成结实率低是当前杏生产中普遍存在的主要问题。矿质元素是果树生长结实不可缺少的重要营养物质,植物叶营养分析已成为了解植物体内营养状况,进行矿质营养研究的一种基本手段。研究杏叶片矿质营养对探索杏花败育原理、杏树营养育种等都具有理论和实用意义,也为合理施肥以改善杏果实品质提供依据。我们根据近几年来杏叶片营养分析技术的研究成果,总结了杏树叶片矿质营养的研究方法、影响因素、动态变化以及叶片矿质元素含量与产量、果实品质等的关系,结合我国杏生产中存在的问题,提出了今后杏矿质营养研究的方向。     

10个南瓜品种的果实性状及营养成分分析

为进一步选育南瓜栽培新品种,对10个南瓜品种的农艺性状、果实性状、营养成分及主要微量元素含量进行分析。结果表明,在各品种农艺性状测定方面‘,百蜜10号’表现出节间长度较短、第1雌花节位较低和单株结瓜数较高。在果实性状方面‘,兴蔬大果’表现较优,其单瓜质量较高(3 318 g)、果肉较厚(3.1 cm),瓜皮主色和肉色为橙黄色。在果实各项口感指标方面‘,百蜜’系列和‘蜜本南瓜’均总体表现较好。在营养成分方面‘,兴蔬大果’的氨基酸和还原糖含量较高,分别为64.64 mg·100 g~(-1)、4.75 g·100 g~(-1);总糖含量最高的为‘蜜本南瓜’,高达10.29 g·100 g~(-1);相关性分析发现,单瓜质量与横径呈极显著正相关,与肉厚呈显著正相关,与TSS呈显著负相关;横径与肉厚呈极显著正相关;果形指数与肉厚呈显著负相关;氨基酸与总糖呈显著负相关。在南瓜果实微量元素中,K含量最高,为142.68μg·g~(-1),且其变异系数最小。经综合分析,10个南瓜品种中农艺性状表现较好的是‘百蜜10号’,果实性状、营养成分和微量元素表现较好的是‘兴蔬大果’,另外‘,蜜本南瓜’表现出纵径较短、横径较粗、果肉较厚等优良短粗形南瓜性状,备受市场欢迎。     

木粒--SPDA的制作与探讨

木粒--SPDA是我们根据木腐生性食用菌在自然状态下,均发生于树木上的特性,以及食用菌在营养需求上与其习性相关的原理,在SPDA基础上添加适量的木粒制成的一种母种培养基.在我们多年的使用中发现,用该培养基培养的母种生长势好,在转接原种时,适应能力强,萌发定植快;用作菌种保藏基质时,保藏时间长,且能很好保持菌种的优良性状.     

黄金宝树幼龄木枝系构型特征及影响因素

为分析黄金宝树(Melaleuca bracteata)幼龄木不同生长高度的枝系构型特征及影响因素,通过统计分析不同高度阶段的枝系构型指标,并采用主成分分析法分析影响枝系构型的因素。结果表明:随着高度的增加,树高、地径、冠幅均值、树冠体积、逐步分枝率1,2与枝径均值对枝系构型的影响趋于上升;总体分枝率、逐步分枝率2,3、逐步分枝率3,4与枝条倾角均值对枝系构型的影响则增减不一。第1主成分的贡献率在23.61%~60.32%间,当高度小于60 cm时,树冠体积、枝径均值及冠幅均值是影响枝系构型的主要影响因素;高度在60~80 cm时,树冠体积和冠幅均值是主要影响因素;高度在80~100cm时,逐步分枝率1,2和总体分枝率是该阶段的主要影响因素;高度在100~120 cm时,逐步分枝率1,2、冠幅均值及枝径均值为主要影响因素。高度超过120 cm时,逐步分枝率1,2的绝对值最大,说明其为该阶段影响枝系构型的主要因素。     

臭氧水对菠菜幼苗生理特性及营养成分的影响

以大田菠菜为试验材料,采用1.0 mg·L~(-1)臭氧水土壤浇灌和0.6 mg·L~(-1)臭氧水叶片喷施处理,测定菠菜幼苗相关生理指标和营养成分。结果表明,臭氧水浇灌和喷施处理显著增加菠菜幼苗鲜质量,分别比对照增加了80.07%和14.49%,明显促进菠菜幼苗生长;显著降低菠菜叶片质膜透性,分别比对照降低了53.85%和46.15%,提高了菠菜幼苗的抗逆能力;显著增加菠菜叶片氮素含量、SPAD值和叶绿素含量,浇灌处理分别比对照增加了30.74%,54.17%和125.32%,喷施处理分别比对照增加了12.45%,26.28%和89.87%,明显提高了菠菜幼苗的光合能力;显著增加菠菜叶片Fe、B和Mn含量及维生素C和可溶性糖含量,浇灌处理分别比对照增加了62.69%,30.08%,70.48%,22.58%和100.69%,喷施处理分别比对照增加了52.24%,21.59%,20.75%,9.68%和29.95%,明显改善了菠菜幼苗生理特性,提高了产量和品质。与叶片喷施处理相比,臭氧水浇灌处理的效果更好。     

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.     

Balancing landscape-level forest management between recreation and wood production

Although many forested landscapes are used for both wood production and outdoor recreation, intensive forest management can negatively impact the recreational value of forests, including in Sweden, a country with rich forest resources and a strong forest industry. In Sweden, urbanization has increased the importance of, and demand for, urban and peri-urban recreational green areas such as forests. It is the responsibility of the local government – i.e., the municipalities – to provide a good living environment for its inhabitants, including recreational areas. However, most of the forest areas in Sweden are owned by private individuals and companies, which have a large degree of freedom in their forest management decisions. Municipalities can make formal agreements with forest owners to protect forests with high recreational values, but this requires financial resources, which are often scarce. Thus, tools are needed to identify the forest areas that should be prioritized for the use of forest management strategies that maintain or increase the recreational value of forests. In this study, we elaborate an approach that balances economic and recreational forest values within a forest decision support system (DSS) and test the approach for a case study area in southern Sweden. The recreation model included in the forest DSS links locational aspects, such as population density and proximity to water, with forest structure aspects, which are simulated over time under different management strategies. Our results suggest that the model could be useful for more efficient planning of the recreational potential of forests at the landscape level. The results from the case study indicate that substantial increases in the recreational value of a forest landscape can be achieved with relatively small overall economic losses, for example, by extending rotation periods in forests close to densely populated areas.     

枝梢环剥对荔枝新梢生长和叶片矿质营养的影响

环剥处理中断韧皮部光合产物向下运输及抑制枝梢生长的效应已经明确,但对不同矿质营养运输的影响则有待进一步揭示。研究以妃子笑荔枝为试材,揭示了枝梢环剥处理对新梢生长和叶片矿质营养的影响。结果表明,枝梢环剥处理可强烈抑制枝梢上的新梢发生;环剥17 d后,叶片叶绿素指数明显下降;同时,环剥口上端的叶片不同的矿质营养发生不同的变化。其中对钾和镁影响微弱,而氮、磷、钙、铁、锰、铜、锌等矿质营养含量发生不同程度降低,其中微量元素铁、铜、锰的含量下降较为明显,这表明,中断韧皮部运输也会导致叶片摄取这些矿质元素的减少。     

梨成熟花药中生长调节物质及矿质元素含量的分析

以丰水和新高梨为试材,分析了花药内花粉量和花粉的萌发特性,并在即将开花的花蕾期,对其花药中不同种类和形态的多胺、生长素、脱落酸以及矿质元素进行分析,以探讨蕾期花粉生活力高的原因。结果表明:丰水梨每个花药中有大量花粉,并且花粉的萌发率高,达到84.8%,而新高中花粉非常少,并且生活力非常低;丰水梨花药中腐胺、亚精胺和精胺的总量均极显著地高于新高;而且丰水中不同形态(游离态、高氯酸可溶共价结合态高氯酸不溶共价结合态)的3种多胺也都显著或极显著地高于新高;生长素、脱落酸与多胺表现出同样的规律;丰水矿质营养中的钾、钙、镁、铁、铜和锌含量也高于新高,在这些元素中以钾含量为最高,微量元素中以锌含量为最高。     

Preservation of scion wood of Rosa

A method was developed for the preservation of scion wood, which would allow budding to be done earlier in the year than is possible at present. There were few significant differences in bud-take between stored and fresh buds. However, budwood stored at 0.6°C gave better bud-take than wood stored at 4°C. Thus, scion wood collected in the autumn, when it is often abundant, can be stored for a whole year.