桃树的冬季修剪技术

1 桃树整形修剪的依据和原则 桃树喜光性强，内膛光线不足时，易造成小枝枯死，必须注意树冠内膛的透光，开张树势，枝组开心，防止出现背上强、背下弱的现象。在整形修剪中，要注意骨干枝弯曲延伸，先端多疏枝，背上不留大枝组。芽具早熟性，1年内能生长多次，可充分利用夏剪，利用2～3次枝加速整形，培养枝组。桃的萌芽力、成枝力均强、潜伏芽数量少，要注意枝组经常更新。整形修剪的原则是有形不死，无形不乱，充分利用空间，做到密株不密枝，有空则留，无空则疏，培养合理树形。     

密植桃树延迟二层开心形整形要点

现向广大果农介绍密植桃树的延迟二层开心形。该树形具有控制树冠外扩过快,通风透光好,行间交接晚,内膛枝充实,空间利用充分,产量高等特点。其整形修剪步骤如下。     

不同树龄的桃树整形修剪技术

桃树的一生要经过幼树期、初果期、盛果期和衰老期4个时期,在不同树龄时期内,整形修剪有着不同的要求,要正确处理树体生长、发育枝、结果枝、长枝及大量副梢之间的关系,以促进树体早果丰产。本文结合生产实践,对不同树龄的桃树整形修剪进行了分类指导,有利于指导果农生产实践。     

防止桃树内膛光秃的修剪措施

防止桃树内膛光秃的修剪措施桃树是喜光性强的果树，光补偿点较高，极易因光照不足使冠内小枝枯死，结果部位很快外移，降低产量，缩短寿命。为防止桃树内膛光秃，我们采取了以下几方面的修剪措施。１、幼树合理整形幼树整形应掌握主干矮、主枝少的原则。注意采用里芽外蹬...     

桃树内膛光秃的原因及对策

桃树是喜光性强的树种,潜伏芽少,寿命短。生产中常因整形修剪不当等原因,内膛花芽少而瘦弱,重者造成内膛光秃,结果部位外移,产量低,效益差。 一、内膛光秃的原因 1.整形修剪不当 生产中主要有主枝开张角度小,多在40～50°;主枝呈直线延伸生长,内膛枝条过密,徒长枝疏除不及时;结果枝     

桃树内膛光秃的原因及解决办法

桃树是我县主要栽培果树之一,因其结果早、收益快等优点,深受广大农民的青睐。但在桃树生产中因整形修剪不当、病虫危害等因素,造成内膛枝条细弱,难以成花,重者导致树冠内膛光秃,结果部位外移,产量低，经济效益下降。因此，桃树内膛光秃、结果部位外移成为当前困扰桃树生产的一个主要因素，影响了农民发展桃树的积极性。现就生产中造成桃树内膛光秃的原因和解决办法总结如下。     

桃树内膛光秃的原因及对策

桃树是喜光性强的树种,潜伏芽少,寿命短。生产中常因整形修剪不当等因素,造成内膛枝条细弱难成花果,重者导致树冠内膛光秃,结果部位外移,产量低,效果差。 1 内膛光禿的原因 1.1 整形修剪不当 生产中主要表现在主枝开张角度小,多在40～50°,主枝呈直线延伸生长;内膛枝条过密,徒长枝疏除不及时,结果枝组更新不合理等。 1.2 大小年结果 桃树负载量过大是引起盛果初期内膛过早光秃的主要原因之一,表现为     

应用修剪技术防止桃树内膛光秃

桃树是喜光性果树,光补偿点较高,极容易因为光照不足使树冠内小枝枯死,结果部位外移,产量降低,寿命缩短。为防止桃树内膛光秃,在修剪方面常采用如下措施。 1)幼树合理整形。幼树整形应掌握主干矮、主枝少的原则,利用外芽枝、副梢开张主枝角度,使骨     

桃树的整形修剪

一、桃与修剪有关的几个特性 1.桃树非常喜光,光线不足小枝易枯死。因此必须注意树冠内部的光照,保证内膛上不遮天,树姿开张,枝组开心。 2.桃树极性强,易出现上强下弱,背上强,背下弱。在整形修剪中要对骨干枝左右拐弯,先端多疏枝,背上不留大型枝组。     

苹果树改良纺缍形修剪要点

近年来 ,有些苹果园产量不高 ,优果率低 ,其主要原因是 :果农对密植园依旧采用传统的树形及修剪方法 ,导致已进入结果年龄的苹果树 ,大枝多、长势旺 ,短枝、小枝少 ,树冠郁闭 ,花芽形成少 ,内膛光秃 ,结果部位外移。要想获得苹果丰产稳产 ,应采用如下整形修剪措施。1 　严格按照改良纺缍形进行修剪 ,逐年改造 ,3 -5年内改造成形。2 　疏除过密骨干枝、对生枝、轮生枝、下层背上直立枝及上层过大侧生枝 ,为内膛密生枝和长脖枝打开光路 ,改善透光条件 ,保留第 1层侧枝。3　对保留的骨干枝除下部三大主枝开角85度外 ,其余枝条都拉至水平 ,选用…     

Effect of salinity and water table on growth and tolerance of plum and peach

The effects of combinations of salinity (no salt, 2000 p.p.m. or 4000 p.p.m. of CaCl₂ and NaCl, 1:1) and water table (30 cm, 60 cm or 90 cm from the soil surface), on the vegetative growth and tolerance of ‘Golden Japanese’ plum and ‘Mit Ghamre’ and ‘Balady’ peaches were studied. The plants were grown in lysimeters. The growth of the trunk, total shoot length, the increase in shoot length per cm and the fresh weight of top, root and total plant were reduced with increasing salinity of the irrigation water. The effect was accentuated when the plants were maintained at high water table level. The salinity treatments resulted in the death of 43%, 73% and 76% of the plants in the plum, and the ‘Mit Ghamre’ and ‘Balady’ peaches, respectively, indicating that the plum is more tolerant to salinity than the peach. The plants of the salinity treatments showed various symptoms of salt injury, such as leaf burn, defoliation, shoot die-back and finally death. In the peaches, salt injury started to occur in the first growing-season, whereas the salt injury appeared in the plum in the second growing-season. The symptoms were more pronounced in the 4000 p.p.m. treatment than in the 2000 p.p.m. treatment and were more pronounced at the high water table level. The salinity level was the predominant factor and the effect of the water table on the vegetative growth diminished with increase in the salinity level of the irrigation water.     

洞庭1号无籽西瓜套种棉花高产高效模式的研究与应用

根据西瓜、棉花两者生长发育特点进行套种试验,研究其高产高效栽培模式。试验示范结果表明,以西瓜行株距4.5m×0.65m,棉花行株距1.5m×0.45m的种植密度,西瓜与棉花之间互颉作用最小,西瓜和棉花的产量和产值在3个套种模式中位居第1,在5个处理中经济效益最高。     

Primary culture and identification of mouse PASMCs and effects of hypoxia on proliferation and apoptosis of PASMCs

AIM：To establish a fast, accurate and economical technique for culturing mouse pulmonary arteriolar smooth muscle cells (PASMCs), and to explore the effects of hypoxia on the proliferation and apoptosis of the PASMCs. METHODS：In sterile condition, the pulmonary artery was isolated from the male BALB/c mice by digesting with collagenase I, and the cells were cultured in fetal bovine serum-coated flask. Centrifugal procedure was not used during the cell passage. The cell morphology was observed under an inverted phase-contrast microscope. α-Smooth muscle actin was identified by immunocytochemistry and immunofluorescence. The effects of hypoxia on the proliferation and apoptosis of the PASMCs were detected by CCK-8 assay and TUNEL assay. RESULTS：PASMCs were identified by the methods of immunocytochemistry, immunofluorescence staining and observation of morphology. Unlike the rat PASMCs with typical subcultured peak-vally pattern, the mouse PASMCs showed a lot different without a peak-vally pattern. The cells could be subcultured after 5 d to 7 d and there was 3 to 5 generations depending on the activity of the cells. CCK-8 assay demonstrated that the A values of PASMCs exposed to hypoxia increased after 24 h (P＜0.05) as compared with normoxia. TUNEL result showed that the apoptotic index of the PASMCs in hypoxia decreased after 24 h (P<0.05). CONCLUSION：This technique for obtaining cultured mouse PASMCs is simple, fast, accurate and economical. The digestion time is easy to control. Hypoxia promotes the proliferation and inhibits the apoptosis of PASMCs.     

小檗碱和壳聚糖抗蔬菜病原真菌活性测定及复合膜制备

研究了小檗碱和壳聚糖对几种常见蔬菜病原真菌的抑制活性,以及以小檗碱和壳聚糖为主料制备复合膜的方法,并测定了该膜的药物释放效果。试验表明:低浓度(0.234 mg/mL)小檗碱即可抑制辣椒炭疽病菌(Vermicularia capsici)等5种蔬菜病原真菌的生长。20 mg/mL浓度壳聚糖对番茄灰霉病菌(Botrytis cinerea)的抑制率高达65%,而对其余4种果蔬病原真菌也有一定的抑制作用。为了集成这2种天然化合物的优点,制备了小檗碱-壳聚糖复合膜,该膜具有缓释功能,在模拟外部环境(磷酸缓冲液,pH 6.8)条件下,20 d小檗碱累计释放率接近25%,提示其在果蔬贮藏抗菌中的应用价值。     

钾肥在小白菜和萝卜上的施用效果

采用盆栽试验方法研究了施用钾肥对小白菜、萝卜生长发育、产量、品质及钾素含量的影响。结果表明 ,施用钾肥对小白菜和水萝卜的株高、叶片数无显著的影响 ,但可提高水萝卜块根的产量 ,提高幅度为 31.0 4 %～ 97.93%。施用钾肥可提高小白菜和萝卜的蛋白质和VC含量 ,降低硝酸盐含量 ,增加植株的钾素含量     

西瓜与粮油菜套种栽培试验

近年来,我省西瓜发展速度较快,到2004年全省西瓜栽培面积已达3万hm^2.由于我省耕地面积有限,大幅度扩大西瓜单种面积,不仅造成我省西瓜与粮油菜争地的矛盾,而且土地也未能得到充分有效的利用.为了解决这一生产中存在的实际问题,我们从2002年开始,进行了西瓜与粮油菜套种的栽培试验.历经4年的试验、示范,取得了显著的经济效益和社会效益.现将试验结果报告如下.     

世界及中国鳄梨产销概况与展望

依据联合国粮食及农业组织(FAO)数据库、联合国商品贸易统计数据库(UN Comtrade)中的数据,围绕鳄梨种植面积、产量、迚出口市场、主产国生产情况、主要迚出口国贸易情况等斱面,对世界及中国鳄梨的生产与贸易迚行回顾、分析与展望,幵在此基础上,对中国鳄梨产业的发展提出建议。     

Storability of onion seeds and effects of packaging and storage conditions on viability and vigour

Fresh onion seeds desiccated to 6.0% seed moisture content (SMC) were stored in various packaging materials under different storage conditions. Seeds packed in aluminum-laminated pouches beside those stored with silica gel at 25 °C maintained satisfactory germinability and vigour after 12 months. Desiccated seeds stored in moisture impervious containers produced more vigourous seedlings. Germination potential of onion seeds increased with reduced SMC besides storage in moisture impervious packets along with desiccants as physiological and biochemical attributes are regulated. Seed viability and vigour decreased with accelerated ageing due to increased lipid peroxidation, decreased activities of several free radical and peroxide scavenging enzymes. Electrical conductance of seed leachates also increased with ageing. Thus, adoption of appropriate storage temperature and moisture control techniques would significantly affect onion seed quality, which was due to minimum accumulation of free peroxide radicals and enhanced activity of free radical scavenging enzymes.     

遮阴及地膜覆盖对黄皮果实表面温湿度变化及果实品质的影响

以金鸡心黄皮为试材,研究了遮阴及地膜覆盖处理对黄皮果实品质与果实表面温湿度变化的影响。结果表明：阴雨天气下,遮阴及遮阴＋地膜覆盖处理的果实表面日平均湿度低;晴天天气下,地膜覆盖处理及对照果实表面的日平均温度高,昼夜温差大,阴雨及晴天天气下温度变化、湿度变化趋势基本一致;地膜覆盖提高了果实品质,遮阴及遮阴＋地膜覆盖降低了果实好果率。     

热处理对果蔬采后品质及病虫害的影响

采后热处理是近年来快速发展的果蔬采后处理技术,广泛应用于改善果蔬贮藏期间的品质、增强抗逆性等 方面。从果蔬贮藏期间的生理生化、采后品质及防治病虫害等方面阐述了热处理的机理,讨论了热处理对果蔬衰老 方面的生理特征如色泽、风味、硬度(软化)、失重、呼吸、乙烯释放、酶活性等变化及与抗逆性有关的诱导蛋白质合成 及基因表达的影响,较全面阐述了热处理防治果蔬贮藏期间病虫害的机理如直接作用于病菌、害虫与提高果蔬的抗 病虫性等。