苹果树更新修剪对土壤水分及树体生长的影响

在渭北高原以苹果树长放修剪为对照,监测盛果末期苹果树更新修剪对果园0～500cm土层土壤水分及树体生长状况的影响。结果表明:更新修剪的果园0～240cm土层土壤水分极显著高于长放修剪,240cm土层以下土壤水分与长放修剪无显著差异;更新修剪的果园土壤水分蒸散高峰较高且延迟30d左右,但生长期的平均蒸散强度与长放修剪无显著差异;更新修剪的苹果树翌年新梢总数显著减少,短枝、叶丛枝比例显著降低,中枝、长枝比例显著增加,单果质量、果实产量、经济产值和水分产出率显著提高,但耗水量与长放修剪无显著差异。综上可见,更新修剪改良了果园的土壤水分状况,促进了树体生长,是渭北高原盛果末期苹果树的适宜修剪方法。     

根系修剪对冬枣生殖生长的影响

[目的]研究根系修剪对冬枣(Zizyphus jujuba Mill.)生殖生长的影响及作用机理,为冬枣的高产优质栽培提供指导。[方法]以6年生冬枣为试材,分别在行间两侧距树干3、5和7倍胸径距离处对其进行根系修剪处理,调查各处理枣吊数量、花量、坐果率、产量及果实维生素C(VC)、可溶性总糖、有机酸含量,研究根系修剪对冬枣生殖生长的影响。[结果]3倍胸径根系修剪与对照相比,有效地抑制了枣吊数量和花朵总数,但却极大地提高了坐果率,对产量无明显影响,但却明显提高了维生素C和总糖的含量,降低了总酸的含量。[结论]3倍胸径距离根剪是改善生殖生长的最佳距离。     

Stem respiration is influenced by pruning and girdling in Pinus sylvestris

Abstract

Stem respiration was measured in the growing season (June to July) and in the dormant season (October) to detect cambial activity induced by pruning live branches or girdling stems in Scots pine trees (Pinus sylvestris L.) growing in northern Sweden. Immediately after the treatments, the treatment:control ratio of stem respiration increased to between 1.38 and 1.44 in the pruning treatment and between 1.17 and 1.20 in the girdling treatment. The treatment:control ratio of stem respiration then decreased by the end of July, to 0.65 in the pruning treatment and 0.55 in the girdling treatment. In October, the treatment:control ratios were higher: between 0.87 and 0.97 in the pruning treatment and between 0.85 and 0.97 in the girdling treatment. In both pruning and girdling treatments, the time trends of stem respiration rates largely followed those of stem temperatures: the stem respiration rate increased exponentially with an increase in stem temperature. The Q ₁₀ values were 2.83–4.05 and 2.57–2.89 in the pruning treatment and control, and 2.10–2.60 and 1.99–3.19 in the girdling treatment and control, respectively. In most cases, the values of Q ₁₀ in both treatments did not differ significantly from those in the controls.     

不同修剪整形方法对大铃铛枣产量的影响

通过大铃铛枣树实施主干疏层形、自然开心形、多主枝自然圆头形和超强度修剪等4种剪枝整形对枣树产量的影响试验,结果表明,超强度整形的枣树产量最高,667m2样地达848.4kg,优质果产量占97.8%以上。实施超强度修剪整形是大铃铛枣园增加经济效果的一项关键经营措施。     

红地球葡萄花穗整形方式研究

以5年生红地球葡萄为试材,分别进行留穗尖8 cm、10 cm、12 cm、14 cm、16 cm及剪短小分枝、去上去下留中间和去主穗留副穗8种整穗处理,研究了不同花穗整形方式对红地球葡萄果实品质的影响,筛选出红地球葡萄省工、优质的整穗方式。结果表明:留穗尖10 cm的单粒质量最大,留穗尖8 cm、12 cm和16 cm的可溶性固形物含量明显高于其他处理,留穗尖12 cm和14 cm的单宁含量显著低于其他处理,留穗尖8 cm、10cm和12 cm均要比去上去下留中间整穗有利于着色。留穗尖12 cm的综合效率最高,留穗尖14 cm综合效率最低。不同整穗方式的主成分综合评价结果为,留穗尖12 cm留穗尖10 cm留穗尖8 cm去主穗留副穗方式剪短小分支式整穗留穗尖14 cm留穗尖16 cm去上去下留中间式整穗。确定留穗尖12 cm是红地球葡萄省工、提质的较佳花穗整穗方式,可为我国红地球葡萄花穗整形提供理论依据。     

Effects of pruning on the concentration of secondary metabolites in Colophospermum mopane leaves

Colophospermum mopane, commonly known as mopane, produces secondary metabolites during the growing season. However, there is still insufficient knowledge on the quantity of secondary metabolites and the effect of browsers on the concentration of secondary metabolites. A pruning experiment was conducted in the Musina Nature Reserve, Limpopo province, South Africa, to simulate the effect of browsers on the concentration of secondary metabolites in mopane leaves. The twigs from 40 selected experimental mopane trees were pruned back 50 mm from their tips using a hand shear. The total amount of leaf and shoot biomass removed from branches of selected experimental trees was less than 10%. Three independent samples composed of seven mopane leaves per 40 mopane trees were randomly collected from the canopies of experimental and control trees per sampling event. The dried leaves from each three independent samples were then mixed separately and a pooled sample of 10 g per treatment per sample cycle (55 d) was used for determination of total phenols (TP), condensed tannins (CT) and protein-precipitating tannins (PPT). Results showed that <10% pruning does not have an effect on the amount of secondary metabolites in the mopane leaves. The concentration of TP, CT and PPT increased during leaf flush in October and then declined as the leaves matured and aged. It is concluded that the amount of secondary metabolites in mopane leaves is not dependent on <10% pruning, but appeared to be associated with leaf growth stages. The ability of mopane to produce secondary metabolites has implications on the seasonal diet composition and distribution of browsers in mopane woodland.     

丘陵地区鹰嘴蜜桃果树修枝装置的设计

针对丘陵地区鹰嘴蜜桃果树修枝费时费工的问题,结合种植区域地形特点和果树枝干分布特性,设计一套易于果农操作的修枝装置,该修枝装置包括修枝执行机构、电动伸缩机构、支撑小车、电气控制4部分。采用圆锯刀修枝方式,根据树杆对锯片的作用力选择修枝电机的功率;采用滚珠丝杆实现修枝执行机构的伸缩功能,避免果农攀爬;支撑小车的设计解决了果农手持修枝工具费力的问题。该装置适用于平地、山地等多种地形,安全可靠,省时省力,大大提高了修枝效率。     

修剪与施氮对板栗叶片N、P营养及产量的影响

为探究修剪与施氮量对板栗树体叶片氮磷含量、氮磷比、产量、单粒重及出实率的影响,明确适宜当地板栗的修剪与施氮量的最佳组合,以13年生的板栗燕山早丰为试验对象,采用双因素随机区组试验,研究修剪强度(每平方米投影面积留结果母枝17~18、14~15和11~12个,分别记为X₁、X₂和X₃)与施氮量(施氮为0、375、750 kg·hm^-2,分别记为N₀、N₁和N₂,施磷均为164 kg·hm^-2,施钾为311 kg·hm^-2)的交互作用对板栗叶片氮磷含量、氮磷比、产量、单粒重及出实率的影响。结果表明,N₁(中等氮肥)和X₂(中等修剪)条件下叶片氮含量、结果枝叶片氮磷比、产量、单粒重及出实率最高。X₂N₁、X₁N₂处理的叶片氮磷含量及产量均较高,且2个处理的结果枝叶片氮含量及产量差异显著;X₃N₀处理的产量不高,但其单粒重和出实率均较高。其中,X₂N₁处理的结果枝及营养枝的叶片氮含量(23.179、23.650 g·kg^-1)、结果枝叶片氮磷比(13.67)、产量(3 502.80 kg·hm^-2)、单粒重(8.26 g)和出实率(41.48%)均为最高。板栗树体需氮量随着修剪强度的增强(即单位面积留枝量的减少)而降低,修剪与施氮量2种措施之间具有协同性。从叶片氮磷含量及产量等指标综合考虑,X₂N₁处理是当地修剪与施肥的最佳组合。综上,中等修剪强度配合中等氮肥在增加叶片营养的基础上,保证了板栗的单粒重和产量。本研究为迁西地区板栗高产栽培提供了理论依据。     

不同修剪强度对紫薇生长及开花性状的影响

为了探明不同修剪强度对紫薇生长性状和开花性状的影响,为紫薇的科学修剪提供理论依据和指导。以4年生紫薇杂交苗为试验对象,研究了不同修剪强度处理对紫薇新梢生长及开花的影响。结果表明,不同强度修剪可显著降低株高及冠幅;各修剪处理的新梢萌发数量显著高于对照,2/3强度修剪处理的新梢生长量最大;修剪可显著提高着花密度,随着修剪强度的增加着花率呈递增趋势;修剪处理对花序长、花序宽没有显著影响。相关性分析表明,株高与冠幅、花序长和花序宽呈显著正相关,与着花率呈显著负相关;冠幅与着花率呈显著负相关;花序长与花序宽呈极显著正相关。研究证明,2/3强度修剪对促进新梢生长、提高着花密度、有效控制株型效果最佳,有利于矮灌型紫薇的培养。     

基于美国山核桃不同枝条粗度的修剪技术研究

为提高美国山核桃采穗圃穗条产量和质量,针对不同粗度枝条开展了修剪技术研究。结果表明:枝条粗度为10~15mm,以留存2个芽为宜,成枝数为0.78根,新枝最大粗度为12.44mm;新枝粗度为15~20mm,以留存8个芽为宜,成枝数达4.22根,新枝粗度为13.35~14.51mm;枝条粗度为20~30mm,以留存6~8个芽为宜,成枝数达5.33~5.89根,新枝粗度为17.82~20.24mm。