山地苹果树更新修剪对树体营养及生长的影响

 在陕北黄土丘陵沟壑区以常规修剪为对照,探讨更新修剪对盛果期山地苹果树体营养和生长方面的影响。结果表明：更新修剪提高了叶片、枝条中的氮、磷、钾、钙含量,提高了果实中的氮、钾、钙含量,对果实中的磷和根系中的磷、钾无显著影响;降低了根系中的氮、钙含量;显著增加了长枝、中枝的比例,显著降低了短枝、叶丛枝比例,促进了枝条健壮发育。更新修剪增加了叶面积,提高了叶绿素、单果质量、果实维生素C和有机酸含量,对果实可溶性固形物、总糖、着色面积等无显著影响,提高了果实产量,极显著提高了果园的经济产值。     

核桃整形修剪技术

1修剪时期核桃修剪要避开伤流期,适宜修剪时期应在采收后至叶片变黄以前。2适宜树形晚实类型多用疏散分层形,早实核桃多用自然开心形。密植核桃园还可采用自由纺锤形和细长纺锤形。     

核桃休眠期修剪对生长结果的影响

通过试验表明,核桃休眠期修剪不仅对生长结果没有不良影响,而且能增加分枝数,促进新梢生长,提高产量,建议生产中推广。     

核桃放任生长树的改造修剪

我省部分地区,核桃管理粗放,只是在郁闭的情况下,每隔几年进行一次清膛川枝.这种方法,虽然在一定程度上暂时改善了通风透光条件,但更加促使内膛空虚,结果部位外移,树势衰弱,产量很低.开展放任树的改造修剪是迅速提高核桃产量、增加农民收入的一项重要技术措施.     

核桃伤流发生规律研究

通过对核桃伤流发生规律的研究,掌握和了解了伤流发生的规律,明确了在伤流期修剪核桃对生长发育及产量是否有影响,为合理安排核桃修剪时期、嫁接时间和嫁接步骤提供了可靠的依据.     

核桃休眠期伤流规律的研究

核桃伤流在整个休眠期中任何时间修剪均有发生。无论枝条粗细 ,剪后 7～ 10天内有不同程度的伤流从剪锯口大量流出 ,以后急剧减少 ,虽有波动 ,但没有大的高峰。核桃 1年生枝伤流量较少 ,其次是粗 3～ 5cm的枝 ,5cm以上枝伤流量较多 ,且持续的时间长。核桃伤流的多少 ,受当时气温、地温的影响较大     

核桃整形修剪技术

<正>1确定适宜的整形修剪时期核桃修剪时期与其它果树不同,如果修剪时期不当,伤口会引起"伤流",使养分流失,造成树势衰弱,甚至枝条枯死。丹凤县核桃伤流期一般在秋季果实采收后到叶片未变黄以前和春季展叶以后。为此,核桃修剪要避开伤流期,适宜修剪的时期应在白露至寒露之间。     

修剪时期对早实核桃枝条中淀粉含量的影响

为探明早实核桃适宜的修剪时期和修剪方法,以6年生早实核桃"绿岭"为试材,采用秋季修剪和春季修剪处理5个不同粗度的修剪枝,分析了不同修剪时期对枝条不同部位淀粉含量的影响。结果表明:T3处理呈现出春季修剪皮层淀粉含量显著高于秋季修剪;除T2处理外,其它处理均表现为春季修剪枝条木质部淀粉含量显著高于秋季修剪;1年生T4、T5处理和多年生T3处理春季修剪的枝条髓淀粉含量显著高于秋季修剪。因此,春季修剪比秋季修剪有利于枝条中淀粉的积累。     

核桃树的修剪应避开伤流期

核桃树在休眠期内，因修剪使枝条受伤，输导组织受到破坏，树体内的营养液会从伤口大量流出(称为“伤流”)，严重削弱树势甚至死亡，所以核桃树修剪必须避开“伤流”期。     

English walnut fruit growth and development

Samples of the ‘Ashley’, ‘Hartley’ and ‘Franquette’ cultivars of English walnut (Juglans regia L.) were collected at weekly intervals from bloom to harvest, and development of the fruit, embryo and surrounding tissue was followed. The first division of the zygote occurred approximately one week after pollination, by which time the endosperm, nucellus and integument had shown considerable growth. The endosperm first formed cell walls at the 8-celled embryo stage and was completely cellular by the time the embryo contained approximately 64 cells. Rapid growth of the cotyledons started as the shell began to harden at Week 7. Measurement of fruit growth indicated that fresh weight gain in ‘Ashley’ and ‘Hartley’ fruits followed a double sigmoid pattern, characterized by a 3-week period of slowed growth that began approximately 7 weeks after bloom. Rate of increase in total length and diameter also slowed greatly at Week 7. Fresh weight gain in ‘Franquette’ appeared to follow a single sigmoid curve, with no prolonged period of slowed growth corresponding to that in the other cultivars. Kernel growth also described a double sigmoid curve, with its initial, rapid phase nearly coincident with the beginning of Stage III of the whole-fruit, fresh-weight curve at Week 10.     

The impact of pruning and mortality on urban tree canopy volume

Urban trees provide a wide range of ecosystem services for city residents, with tall, mature trees with wide crowns generally regarded as preferable. The tree biomass which is responsible for shading, pollution removal, rain runoff retention etc. gets periodically reduced by the municipal tree management practice of pruning. This is a necessary activity, which reduces the risk of infrastructure damage and falling branches, but many estimates of ecosystem service provision in cities do not consider its impact explicitly. Tree mortality is also higher in cities, preventing trees from attaining and remaining at large sizes. This study used extensive field measurements of tree structure to estimate the impact of pruning on 8 tree species in two Italian cities: Taranto and Florence. Crown widths were reduced by 1.6 m on average, however there is large variation between species variation with branches more often being removed for thinning crowns resulting in larger gap fractions, which increased by 15% on average. No significant differences were observed for crown widths or gap fraction between trees pruned 3 and 4 years previously, suggesting that tree crowns structurally recover from pruning after 3 years. A deterministic model revealed that current urban forest pruning rates (every 6 years) and mortality (1%) may create a situation in which a city dominated by the species studied benefits from 93.5% of the maximum ecosystem services possible. This work will allow more nuanced estimates of urban forest services to be calculated.     

Response of watersprout growth to fruit load and intensity of dormant pruning in peach tree

Watersprout occurrence and growth were investigated over a two-year period in an early maturing peach cultivar (Alexandra) under different intensities of dormant pruning for fruited and defruited trees. A preliminary study focused on identifying the laws that determine the probability of presence and occurrence of watersprouts in relation to watersprout-bearing shoot (WBS) length. The increase in watersprout probability of presence and occurrence resulting from greater WBS length illustrated the high capacity of peach for sprouting. Watersprout lengths were measured, as well as the lengths of young shoots, one-year-old fruit-bearing shoots (FBSs) and older branches considered as WBS in order to evaluate total shoot growth within the tree. Watersprout number and total length tended to be higher under severe dormant pruning and in fruited trees than under light dormant pruning and in defruited trees. This stimulation of watersprout length appeared to compensate for the concomitant lower total length of young shoots, resulting in a constant overall vegetative growth rate for the whole tree. In the second year of the experiment, watersprouts were either removed by summer pruning or not in order to evaluate watersprout incidence on the rest of the tree. After light and severe watersprout removal (WSR), the annual diametrical growth of FBS tended to be higher and lower, respectively, compared to trees not submitted to summer pruning. Light WSR might favour light interception in the centre of the canopy, thus improving assimilate production and allocation to FBS, whereas severe WSR could prevent carbohydrate export from watersprouts to FBS. Under our conditions, the limit at which WSR intensity became detrimental for FBS diametrical growth appeared to be after approximately 75% of the watersprouts were removed. Severe WSR appeared likely to improve fruit diameter, whereas it had no significant impact on the percentage of soluble solids.     

设施栽培桃果实采后树体适宜修剪量的探讨

研究设施栽培桃果实采后适宜修剪量,为设施栽培桃不同品种采后修剪提供指导。以曙光与早红艳4 a生成龄树为试材,连续6 a在果实采后对1 a生枝组进行适宜修剪量试验。以不修剪为对照,按剪下叶量占植株总叶量比例进行轻度(20%~30%)、中度(40%~50%)和重度修剪(70%~80%)及全剪处理,分析不同修剪量对树冠的光截获能力、1 a生枝组叶片的净光合速率和1 a生枝组的年生长量以及植株总产量和果实品质的影响。结果表明,对曙光进行中度修剪处理,后期结果枝组能更快形成,短果枝比例降低,更有利于提高单株负载量和果实品质。对早红艳进行轻度修剪处理,枝条总数增加,短果枝比例降低,植株负载量及果实品质明显优于对照,该品种更适于轻度修剪。     

连作土灭菌对葡萄生长及根系分泌特性的影响

为探讨葡萄连作障碍产生的原因,采用盆栽模拟试验,对葡萄连作土壤进行蒸汽灭菌,研究连作土灭菌后葡萄植株生长及根系分泌特性的变化。结果表明,连作土灭菌显著增加了葡萄植株的株高和茎粗,其中以7月份的增加幅度最大,分别比连作土增加了1.51倍和0.14倍,地上和地下鲜质量随着生长期的延长也表现出显著增加的趋势,以9月份的增加幅度最大,分别增加了1.18倍和1.09倍。并且连作土壤灭菌后葡萄叶片SOD酶活性增强,MDA含量降低,根系活力随生长期的延长,表现出先下降再上升的趋势。另外,研究发现连作土壤灭菌后葡萄根系分泌的还原糖及氨基酸总量显著降低,分别比连作土壤降低了72.60%和91.10%;氨基酸的种类及其含量也发生改变,其中Ile、Leu和Tyr3种氨基酸未达到检测水平,其他氨基酸含量降低。可见,对连作土壤进行有效的灭菌后,可以改变根际微生态的核心因素即根系分泌物的成分及含量,促进植株的生长,减轻葡萄的连作障碍,进而证实了土壤生物因素是葡萄连作障碍产生的重要原因之一。     

不同花穗处理对龙眼树叶营养及果实品质的影响

以石硖龙眼为试材,通过花穗短截及疏除花穗等不同处理,对龙眼树叶营养及果实品质的影响进行对比试验。结果表明,花穗短截＋疏除花穗处理使石硖龙眼树体的氮、磷、钾元素的含量保持相对较高的水平,明显提高龙眼果实可溶性固形物含量、可溶性糖含量及还原糖含量,改善果实品质,优于其他处理。     

核桃剪枝木屑对不同香菇菌丝生长速度的影响

为探讨核桃剪枝木屑栽培香菇的可行性,解决废弃核桃剪枝木屑资源的再利用及河北省木屑资源短缺问题,以我省主栽的香菇品种香2、香1、香15、新0912、秋香1和香7为供试菌株,探讨核桃剪枝木屑煮汁的添加对不同品种香菇菌丝生长速度的影响.结果表明,核桃剪枝木屑是很好的碳源,可促进香2、香1、香15、新0912和秋香1菌丝的生长...     

树形对桃树生长、产量和品质的影响

【目的】探讨中油20号桃不同树形对树体生长、产量和品质的影响。【方法】研究3年生中油20号桃Y字形、主干形、三主枝开心形、四主枝开心形及V字形5种树形的夏季结果枝部位光照度,成熟果实品质及冬季树体结构。【结果】同一树形不同部位的光照度和果实品质均有显著性差异,均为上层>中层>下层,不同树形相同部位间差异不显著。每666.7 m²产量为主干形>V字形>Y字形>三主枝>四主枝。树体的主枝数越多,主干直径越粗,树体越高,冠径越大。总枝量主干形最少,四主枝最多,而每666.7 m²枝量V字形最多,主干形其次。不同树形枝类组成,长枝比例顺序为主干形>V字形>Y字形>三主枝>四主枝,中短枝比例与长枝比例相反。选择了13种指标进行主成分分析,5种树形的优劣顺序依次为V字形、四主枝开心形、三主枝开心形、Y字形、主干形。【结论】V字形树形综合评分最高,产量和每666.7 m²枝量较高、品质表现较好,是适宜标准化栽培的优良树形。     

不同树形对早实核桃‘鲁光’坚果产量和品质的影响

【目的】探索适宜‘鲁光’核桃优质高产的树形。【方法】以‘鲁光’核桃树为研究对象,分析主干分层形、开心形和自然圆头形3种树形的结构参数、坚果产量和品质,并进行主成分分析。【结果】主干分层形的树高、基径、骨干枝数、单株平均坚果产量、树冠投影面积平均产量、单果质量、仁质量、种仁粗脂肪和抗坏血酸含量最高;开心形的坚果壳厚最小,出仁率和种仁蛋白质含量最高;自然圆头形的总糖和氨基酸含量最高。坚果外观形状无显著的树形间差异。主成分分析表明主干分层形有利于产量的形成,开心形有利于品质的形成,3种树形的综合排名顺序为主干分层形>开心形>自然圆头形。【结论】济南市章丘区‘鲁光’核桃的适宜树形为主干分层形。     

成龄苹果树形改造对根系生长分布的影响

以成龄红富士苹果为试材,应用壕沟法研究小冠疏层形改造成高干开心形对根系分布状况的影响。结果表明:垂直分布上,改造树总根数增加,直径小于2mm的吸收根密集分布于20～40cm土层,而对照则分布于0～20cm;改造树和对照树水平分布最高峰分别出现在距树干100～120cm和60～80cm处。改造树根干重显著高于对照,提高了13.4%。可见,小冠疏层形改造为高干开心形后,根数目、干重增加;根系向下延伸,向外扩展。