应用多效唑进行珊瑚树和桂花化学修剪的研究初报

珊瑚树和桂花叶面喷布多效唑(PP_(333))可显著抑制枝条的伸长生长,促进加粗生长,并使枝条节间缩短,叶片密集,叶色加深,从而使整个树冠紧凑圆满。化学整形修剪后能较长时间保持原有树形,减少了养护工作量。珊瑚树和桂花的最佳使用剂量分别为2500ppm和1500ppm。     

多效唑对北美冬青‘冬红’盆栽苗生长和光合特性的影响

以北美冬青‘冬红’(Ilex verticillata‘Winter Red’)为材料,研究了不同质量浓度多效唑喷施盆栽苗对其植株生长形态和光合特性的影响,以期探索多效唑对其株型的调控效果及适用质量浓度。结果显示,通过叶面喷施多效唑溶液,能够有效抑制植株株高,控制枝条生长,缩短节间距。随着多效唑质量浓度的增加,叶片叶绿素和类胡萝卜素含量显著增多。在低质量浓度(1 000—2 000 mg/L)处理时,叶片净光合速率、气孔导度、蒸腾速率呈显著上升,高质量浓度(4 000 mg/L)处理导致上述指标降至对照水平;低质量浓度(1 000 mg/L)处理,叶片最大净光合速率(P_{n, max})和暗呼吸速率(R_d)显著增高,高质量浓度(4 000 mg/L)处理使其降至对照水平;低质量浓度(1 000—2 000 mg/L)多效唑处理,叶片光饱和点(P_LSP)和光补偿点(P_LCP)显著增高,而高质量浓度(3 000—4 000 mg/L)处理则显著下降至对照水平。随着多效唑质量浓度提高,植株矮化效果明显,光合能...     

赤霉素和多效唑对天女花移植苗生长的影响

为探讨植物生长调节剂在天女培育中应用的可能性,采用土施法研究了赤霉素、多效唑对天女花移植苗生长的影响。结果表明：赤霉素可以显著促进移植苗的新梢高生长,多效唑可以显著抑制新梢高生长;多效唑可以显著延缓叶片的建成速度、减小叶长和叶宽,赤霉素要以显著加快叶片的建成速度、增大叶片和叶宽;赤霉素、多效唑均可显著增加侧枝的分枝数。     

多效唑控制赤桉冬季生长的分析

1年生赤桉15022叶面喷施和土壤施用多效唑,对当年冬梢生长腋芽萌发均有明显抑制效应,其抑制作用随施用量增加而加强.施用多效唑还能增加叶片叶绿素、可溶性糖含量,并能使叶片在自然低温下维持较高水平的SOD.POD活性,从而提高了赤桉的抗寒性。     

银杏叶面增产素对银杏生长的影响

喷施适宜浓度的银杏叶面增产素，可显著提高叶片的叶绿素及类胡萝卜素含量，提高叶片的光合速率及气孔导度，增加叶面积和比叶重，促进新梢生长，增加叶片产量。研究表明：喷施增产素是通过改善银杏叶片的光合性能来增加银杏采叶产量的。     

多效唑对凯特杏幼树生长和结果的影响

对凯特杏幼旺树适时喷布多效唑，能明显抑制新梢旺长，缓和树势，增加腋花芽结果枝，矩果枝和花束状结果枝的比率，提高座果率，以200，300倍喷布效果较好。     

多效唑对黄桃生长的影响

激素在黄桃生长上的应用已有许多报道,与多效唑同为抑制类型的比久和矮壮素等在黄桃上已有明确的使用浓度和效用,而多效唑在黄桃上的使用尚鲜报道。为此安排本试验,以了解多效唑对黄桃树体生长的影响。材料与方法试验地为4年生黄桃园,园地为山坡缓地,红黄壤,PH值6.7左右,有机质含量约1.2%~1.3%,树冠为自然开心型,种植密度为每亩55株进行一般常规管理与水利管理,试验用多效唑为南京农药厂生产的15%可湿性粉剂。本试验分叶面喷施与土施两种。一、叶面喷施(处理A),安排如下:A0:对照、喷清水;A1:1000mg/L喷施;A2:2500mg/L喷施;A3:5000mg/L喷…     

多效唑对巨峰葡萄生长和结果影响试验初报

本文主要研究了土壤施用和叶面喷洒多效唑对巨峰葡萄生长和结果的影响。通过对不同施用浓度和施用方法的试验证明,除叶面喷洒250ppm处理外,所有处理都抑制了营养生长。其中以土壤施用1、2克和叶面喷洒500、1000ppm的多效唑效果最好。     

多效唑控制赤桉冬季生长的分析

一年生赤按１５０２２叶面喷施和土壤施用多效唑，对当年冬梢生长，腋芽萌发均有明显抑制效应，其抑制作用随施用量增加而加强。施用多效唑还能增加叶片叶绿素、可溶性糖含量，并能使叶片在自然低温下维持较高水平的ＳＯＤ．ＰＯＤ活性，从而提高了赤桉的抗寒性。     

多效唑对梅树生长和结果的影响

应用多效唑对梅树进行叶面喷布和穴施等不同方法，不同剂量试验，叶面喷施５００ｍｇ／Ｌ、穴施０．１２５ｇ／ｍ＾２以上的浓度都可有效地抑制植株营养生长、促进花芽形成，提高果实品质，其中以２月下旬穴施０．１２５ｇ／ｍ＾２综合效果最佳。顺面喷布５－６天见效，持续期约１年；穴施“呆滞期”约２．０－２．５个月，持续期２－３年。     

叶面喷施多效唑对盆栽风信子生长与开花的影响

以风信子品种‘蓝夹克’为供试材料研究了叶面喷施不同浓度的多效唑(PP333)对风信子生长和开花的影响,研究结果表明叶面喷施100 mg/L的PP333延缓‘蓝夹克’的生长,使植株适量矮化、叶面积适度减小,植株更紧凑;与对照相比,叶片厚度增加了5.8%,小花直径增加了2.8%,种球质量增加了5.3%。同时提高了植株叶片的叶绿素含量,将现蕾时间推迟4天,并使花期延长4天,总体上提高了‘蓝夹克’的观赏价值。叶面喷施300 mg/L的PP333因浓度较高,表现出一定的抑制作用。     

多效唑对核桃生长发育的影响及其生理基础*

对８年生晚实嫁接核桃树，于春季新梢长１５ｃｍ左右时进行多效唑叶面喷施处理，试验结果表明，１０００－２０００ｐｐｍ浓度的多效唑可显著抑制核桃树营养生长，以２００ｐｐｍ处理树于８月２７日调查结果为例，新梢长度，节间长度、新梢粗度、干径和叶面积分别分别比对照低６１．５、２１．４、２９．１、２８．２和５９．９％。单株坚果数和产量分别比对照增加５７．９和６４．９％。多效唑对核桃的生理效应包括；降低ＧＡ３、Ｉ     

生长抑制剂对大叶黄杨形态及光合作用的影响

目的]探究抑制剂对大叶黄杨生长的抑制作用以及对其叶片形态和光合作用的影响,为灌木绿篱的化学修剪提供技术指导。[方法]在北京林业大学林场苗圃采用3种生长抑制剂(多效唑(PP_(333))、三碘苯甲酸(TIBA)以及脱落酸(ABA))对密植成绿篱状的1年生大叶黄杨扦插苗进行叶面喷施,对其生长、叶片形态及光合作用等指标进行测定。[结果]3种抑制剂均有矮化植株、抑制新梢生长的作用,矮化效果最佳、抑制作用最强的为PP_(333),且高浓度PP_(333)对于高生长的抑制作用持效性较长。叶宽、叶厚以及叶面积在短期PP_(333)处理下高于对照。PP_(333)能提高大叶黄杨净光合速率,主要通过增加叶厚、气孔导度、叶肉导度及叶绿素含量来实现,并且PP_(333)使蒸腾速率提高的同时降低了水分利用效率。TIBA有显著减小叶长、叶宽的作用,但能使叶厚增加,且随浓度的增加作用效果增强,主要通过减小叶面积,降低叶肉导度、气孔导度、胞间CO_2浓度及叶绿素含量来降低净光合速率。ABA能增加叶面积(10 mg·L~(-1)处理除外)、叶长以及减小叶片厚度,通过抑制气孔导度、叶肉导度、叶绿素含量降低净光合速率。TI-BA及ABA均通过降低蒸腾速率,使水分利用效率提高。[结论]3种抑制剂均有矮化植株、抑制新梢生长的作用,并且影响叶片发育,进而影响叶片光合作用,且800 mg·L~(-1)的多效唑对大叶黄杨具有较好的正向作用。     

一品红千禧品种株型控制研究

研究了摘叶、前期不同时期喷施多效唑和后期低浓度多效唑灌根三种途径控制一品红千禧品种的株型，结果表明：摘2～3叶能明显抑制其顶端优势，降低顶芽株高2．5-2．8cm，在打顶前和打顶后7d进行40mg／L的多效唑喷施，植株矮化效果最好，降低高度13．8cm，后期3张苞叶转色时用1mg／L的多效唑灌根，能降低株高2．9cm，而对苞叶的大小基本无影响，提高了植株的观赏性。     

Triazole induced drought tolerance in horse chestnut (Aesculus hippocastanum)

We determined the influence of the triazole derivatives paclobutrazol, penconazole, epixiconazole, propiconazole and myclobutanil on the drought tolerance and post drought recovery of container-grown horse chestnut (Aesculus hippocastanum L.) saplings. Myclobutanil neither conferred drought resistance, as assessed by its effects on a number of physiological and biochemical parameters, nor affected growth parameters measured after recovery from drought. Chlorophyll fluorescence (F(v)/F(m)), photosynthetic rates, total foliar chlorophyll and carotenoid concentrations, foliar proline concentration and superoxide dismutase and catalase activities were consistently higher and leaf necrosis and cellular electrolyte leakage was lower at the end of a 3-week drought in trees treated with paclobutrazol, penconazole, epixiconazole or propiconazole than in control trees. Twelve weeks after drought treatment, leaf area and shoot, root and total plant dry masses were greater in triazole-treated trees than in control trees with the exception of those treated with myclobutanil. In a separate study, trees were subjected to a 2-week drought and then sprayed with paclobutrazol, penconazole, epixiconazole, propiconazole or myclobutanil. Chlorophyll fluorescence, photosynthetic rate, foliar chlorophyll concentration and catalase activity over the following 12 weeks were 20 to 50% higher in triazole-treated trees than in control trees. At the end of the 12-week recovery period, leaf area and shoot, root and total plant dry masses were higher in triazole-treated trees than in control trees, with the exception of trees treated with myclobutanil. Application of triazole derivatives, with the exception of myclobutanil, enhanced tolerance to prolonged drought and, when applied after a 2-week drought, hastened recovery from drought. The magnitude of treatment effects was in the order epixiconazole approximately propiconazole > penconazole > paclobutrazol > myclobutanil.     

不同栽培条件下枣树幼果期光合作用日变化规律的研究

笔者以10年生壶瓶枣为试材,研究了枣树在灌溉、未灌溉、遮阴、雾化栽培和喷施亚硒酸钠5个处理下光合作用的日变化规律。结果表明:干旱条件降低了树体的光合作用,通过遮阴、雾化栽培和喷施亚硒酸钠可以提高树体的气孔导度,调节叶片的蒸腾,提高树体的光合速率,保证光合作用的进行。亚硒酸钠处理显著提高了叶片上午的净光合速率,气孔导度和蒸腾速率都比其他处理高。     

多效唑对麻疯树结实量的影响

在麻疯树的花蕾期至初花期喷施多效唑,开展了多效唑对麻疯树生长影响及种子产量的研究。结果表明：多效唑对麻疯树具有抑制营养生长,增加果枝率比例,提高产量的综合影响。其中2g／L浓度的多效唑喷施效果最为显著。     

Storage of foliar-absorbed nitrogen and remobilization for spring growth in young nectarine (Prunus persica var. nectarina) trees

The effectiveness of spraying foliage with urea to provide nitrogen (N) to augment the seasonal internal cycling of N in young nectarine trees (Prunus persica (L.) Batsch var. nectarina (Ait. f. Maxim.), cv. Stark Red Gold) was studied. One-year-old trees were grown with contrasting N supplies during the summer and foliage was sprayed with a 2% urea solution labeled with (15)N just before leaf senescence started. After leaf abscission had finished, the trees were repotted in sand and given no further N. Remobilization of both labeled and unlabeled N for leaf growth the following spring was quantified. Leaves absorbed between 58 and 69% of the (15)N intercepted by the canopy irrespective of tree N status. During leaf senescence, the majority of (15)N was withdrawn from the leaves into the shoot and roots. Remobilization of (15)N the following spring was also unaffected by tree N status. About 38-46% of (15)N in the trees was recovered in the new growth. More unlabeled N (derived from root uptake) was remobilized for leaf growth in the spring than was withdrawn from leaves during canopy senescence the previous autumn. Therefore, soil-applied N augmented N storage pools directly, and contributed more to N remobilization the following spring than did foliar-absorbed (15)N.     

Growth of Eucalyptus marginata (Jarrah) seedlings in a greenhouse in response to shade and soil temperature

The effects of shade and soil temperature on growth of Eucalyptus marginata Donn ex Sm (jarrah) seedlings were studied in greenhouse experiments. Plant dry weight and that of all plant parts declined in response to shade, as did root/shoot ratio. Plant leaf area was less in unshaded plants than in plants grown in shade, and specific leaf area increased with shade. Unshaded seedlings had a higher light-saturated rate of photosynthesis, a higher light compensation point and a higher light saturation point than seedlings grown in 70% shade. The relationship between plant dry weight and leaf dry weight was independent of shading, whereas the relationship between plant dry weight and plant leaf area was dependent on shading. Therefore, leaf dry weight may be a better predictor of biomass production than leaf area in forest stands where shade is likely to affect growth significantly. Soil temperature had a significant effect on the growth of all plant parts except cotyledons. Total plant growth and shoot growth were maximal at a soil temperature of 30 degrees C, but root growth had a slightly lower temperature optimum such that the root/shoot ratio was highest at 20 degrees C. Roots grown at 15 degrees C were about 30% shorter per unit of dry weight than roots grown at 20 to 35 degrees C. We conclude that increases in irradiance and soil temperature as a result of overstory removal in the forest will cause significant increases in growth of E. marginata seedlings, but these increases represent a relatively small component of the growth response to overstory removal.     

Response of Ulmus americana seedlings to varying nitrogen and water status. 1 Photosynthesis and growth

Well-watered American elm (Ulmus americana L.) seedlings responded to increased nitrate availability with increased leaf nitrogen (N) concentration and photosynthetic rate, larger and more numerous leaves, greater total growth and greater proportional allocation of carbon to shoot than root. Plasticity of growth and carbon allocation were greater than plasticity of N concentration and photosynthetic capacity. For a given N availability, allocation of N per unit leaf area was positively correlated with dry mass per unit leaf area (specific leaf mass), but these relationships differed with N availability. Rates of net photosynthesis and leaf conductance declined logarithmically with decreasing predawn water status. Increased water stress resulted in a greater relative decline in net photosynthesis and leaf conductance for high-N than low-N plants.