南逗迈4号芒果产期调节技术研究初报

以南逗迈4号芒果树为试材,采用不同栽培措施进行产期调节试验研究。春季重剪配合多效唑溶液土壤浇淋、KNO3叶面喷施处理的末级梢平均开花率为54.6%,平均单株产量为21.6 kg,单纯KNO3叶面喷施处理末级梢平均开花率为13.9%,平均单株产量为12.9 kg。试验结果表明,南逗迈4号芒易于催花,采用春季重剪配合多效唑溶液土壤浇淋、KNO3叶面喷施处理可获得较高的开花率,套黑色双层纸袋可使果皮干净细滑,商品外观好,具有良好的产期调节生产应用前景。     

调节栽培技术条件下土施多效唑对四季蜜杧反季节开花结果的综合效应

在春季施肥、修剪的情况下,在2005年6月11日,对四年生四季蜜杧单株分别用1.0、2.0、3.0、4.0 g多效唑进行土施处理,结果表明,3.0 g/株处理和4.0 g/株处理的四季蜜杧8月份成花率显著高于对照的,3.0 g/株处理的成花率最高,为87.0%。处理剂量达到或超过3.0 g/株时,叶片变短、变窄,叶片数增加,但枝条长度未受影响。单花序花期9～10 d,开花前期两性花比例高,后期低,2.0 g/株处理的两性花比例最高。从多效唑对四季蜜杧成花率、坐果率、产量以及叶片正常发育等方面的综合影响来看,以2.0 g/株处理的效果较好。     

多效唑在沙糖橘控梢促花上的应用试验初报

多效唑是一种应用较为广泛的植物生长调节剂,具有延缓植物生长、抑制茎伸长、提高作物产量和抗逆性等作用,在沙糖橘种植中还具有保果、促花的作用。为探究多效唑在沙糖橘控梢促花上的应用,采用不同浓度的多效唑对沙糖橘进行处理。结果表明,沙糖橘树梢数、开花数、着果数和着果率均随着喷施的多效唑浓度的增加而增加,但树梢长度随着多效唑浓度的增加呈降低趋势。在沙糖橘种植过程中,喷施700 mg·kg~(-1)的多效唑溶液效果最好,梢数达280.4条,梢长9.2 cm,花的数量为9 821朵,着果数为4 920.1个,着果率为50.1%;与对照相比,树梢数、开花数、着果数以及着果率均增加,且差异均达到显著水平,适于在沙糖橘控梢促花中应用。     

多效唑浸种对黄秋葵种子萌发及幼苗生长的影响

采用多效唑(PP333)对‘川秋葵1号’种子进行浸种,以研究多效唑对川秋葵1号种子萌发及幼苗生长的影响。试验结果表明,用25 mg/L、50 mg/L、75 mg/L、100 mg/L的多效唑浸种,对黄秋葵种子的发芽势、发芽率、出苗率影响不大,没有明显抑制作用;用125 mg/L、150 mg/L多效唑处理,会在一定程度上降低种子的发芽势、发芽率、出苗率。多效唑能提高种子的简易活力指数,有效矮化红秋葵幼苗,增加幼苗的茎秆粗度,优化幼苗的株型。综合比较多效唑各处理在形态及发芽各项指标的影响结果,以浓度100 mg/L的多效唑浸种处理的效果最佳。     

多效唑对花生种子萌发及植株生长的影响

以不同浓度的多效唑，对花生种子进行浸种处理和盛花期叶面喷施，观测种子萌发、幼苗生长情况和植株农艺性状，收获时进行产量测定。结果表明：(1)多效唑浸种延缓花生种子萌发，使发芽率有所下降，矮化植株；(2)盛花期喷施适宜浓度的多效唑能抑制花生地上部分的生长，促进其横向生长，使主茎和分枝比对照的短，分枝数、单株结荚数、饱果率和产量均比对照的高，其中以喷施150mg／L多效唑的处理产量最高，达3806．3kg／hm^2，比对照增产12．60%。     

植物延缓剂对盐碱胁迫下羊柴幼苗根系形态的影响

应用盆栽控盐方法,通过模拟毛乌素沙地实际盐碱状况,研究不同质量浓度(0,150,300,450,600mg/L)植物延缓剂(以多效唑为例)对盐碱处理(全盐量0.94g/kg,处理时间3个月)下羊柴(Hedysarum laeve)根系形态特征的影响。结果表明:(1)盐碱胁迫会抑制羊柴根长的生长,降低根系与土壤结合面积及分支强度。其中,分叉数和交叉数所受的抑制作用最明显,分别较对照降低了77.54%,87.70%。(2)多效唑处理会促进羊柴根的生长,600mg/L多效唑处理后羊柴根长、根尖数、分叉数、交叉数、根表面积、根体积分别较单独施盐处理增加了87.66%,116.62%,136.11%,302.25%,57.50%,31.33%,说明多效唑可以缓解羊柴的盐害作用。(3)综合考虑6项根系形态指标,质量浓度为600mg/L的多效唑对提高羊柴耐盐性的效果最佳。     

多效唑施用量对椒苗期生长的影响

以辣椒幼苗为试验材料,设置3个浓度梯度,验证不同浓度的多效唑浸根处理对植株生长的影响。结果表明:随多效唑浓度提高,辣椒幼苗株高和各部分干重降低,茎粗和根冠比先上升后下降,浓度为100 mg/kg时,壮苗指数最高;200 mg/kg浓度处理辣椒叶绿素a含量最高,表现出了很好的壮苗效果。因此,应选择200 mg/kg浓度多效唑处理辣幼苗。     

百合试管苗的移栽对比试验

在含25μg/L多效唑手根培养基或结鳞茎培养基中培养后移栽,可显著提高百合试管苗移栽成活率,促进幼苗生长,其中以促进试管苗在试管内生成鳞茎再移栽途径的效果最好。鳞茎大小对幼苗生长有明显影响,以直径5－11mm的结磷苗进行去叶留根处理后,移栽效果最好。多效唑残留药效低。     

叶面喷施多效唑对紫云英种子产量及结实特性的影响

【目的】通过花前叶面喷施多效唑，探讨多效唑对紫云英产量及其结实特性的调控效应，以期为增加紫云英籽粒数、提高产量调控技术的研究提供参考。【方法】试验以‘信紫1号’为供试材料，设多效唑喷施浓度0 (CK)、200 mg/L (T₁)、300 mg/L (T₂)、400 mg/L (T₃)、500 mg/L (T₄)、600 mg/L (T₅)，喷施溶液量均为750 kg/hm2，在开花前喷施一次。紫云英成熟期，按常规考种法调查单位面积株数、分枝数、不同层花序的花序数、结荚数、籽粒数等指标。【结果】与CK相比，喷施不同浓度多效唑处理的单位面积花序数、结荚数、单荚籽粒数和结实荚果率在不同层花序上均较对照有所提高，以T₃处理提高幅度最大。在第1～6层花序上，T₃处理的单位面积花序数较对照提高34.1%～59.0%，单位面积结荚数提高39.7%～68.4%，单荚籽粒数提高44.3%～53.7%，结实荚果率提高1.84～4.89个百分点。相关分析表明，紫云英种子产量与其单位面积花序数、一级分枝花序数、单个有效花序结荚数、结实荚果率及单荚籽粒数呈显著正相关。多效唑喷施浓度与紫云英种子产量及以上结实因子的相关性均达到极显著水平，以多效唑喷施浓度373 mg/L最优，种子产量最高。【结论】在紫云英花荚脱落高峰之前 (开花前)，叶面喷施多效唑可显著促进不同层花序单位面积花序数、结荚数、结实荚果率和单荚籽粒数的增加，尤其对促进第5、6层花序花荚结实成粒的效果显著，进而获得较高的种子产量。     

喷施矮壮素和多效唑对紫云英生长发育及结实性状的影响

  【目的】  研究不同时期喷施矮壮素和多效唑对紫云英生长发育及结实的影响，明确有利于增产的最佳喷施时期，为提高紫云英种子产量提供有效的化控途径。  【方法】  选取紫云英品种‘信紫1号’为供试材料，分别于越冬后期、返青期、现蕾期、初花期和始花后5天在叶面喷施矮壮素或多效唑 (浓度均为400 mg/kg)，以叶面喷施清水为对照。于盛花期，调查株高、茎粗、分枝数、SPAD值、单株重等生长指标，成熟期按常规考种法考察记载花数、荚数、籽粒数、结荚率和荚果结实率等结实性指标。  【结果】  现蕾期叶面喷施矮壮素和多效唑均可有效抑制植株株高，提高分枝数、SPAD值和单株重，多效唑喷施效果好于矮壮素。与喷清水对照相比，现蕾期喷施矮壮素的紫云英花数、荚数、籽粒数、结荚率和荚果结实率分别显著提高了16.32%、21.45%、15.94%、2.38个百分点和0.94个百分点，而其在越冬后期和返青期喷施却显著降低各指标；现蕾期喷施多效唑的紫云英花数、荚数、籽粒数、结荚率和荚果结实率分别显著提高了31.69%、43.41%、29.49%、4.76个百分点和2.14个百分点，在越冬后期喷施显著降低花数和荚果结实率。矮壮素和多效唑均在现蕾期喷施的种子产量最高，两者较对照分别增产15.95%和29.88%。  【结论】  在紫云英现蕾期，叶面喷施植物延缓剂多效唑和矮壮素，均可显著促进花期花荚发育，减少花荚脱落，促进花荚结实成粒，最终获得较高的种子产量，多效唑效果好于矮壮素。     

Effect of paclobutrazol on microbial biomass,respiration and cellulose decomposition in soil

Paclobutrazol is a plant growth regulator largely utilized in mango cultivation and usually applied directly to soil. The aim of this study was to examine the effect of paclobutrazol on soil microbial biomass, soil respiration and cellulose decomposition in Brazilian soils under laboratory conditions. Soil samples were collected from fields with and without a reported history of paclobutrazol application. A solution of paclobutrazol (8 mg of active ingredient kg^?1 of soil) was added to soils, which were then incubated at 28 °C for 30 days. Paclobutrazol decreased soil microbial biomass, soil respiration and cellulose decomposition in soil with and without a report of paclobutrazol application, while significant increase was observed in the respiratory quotient (qCO₂). Our results show that the soil microbiological attributes were negatively affected by paclobutrazol in short-term experiment.     

保水剂施用方式对土壤水盐及番茄生长的影响

 为探讨保水剂不同施用方式的应用效果,在河套灌区,以不施为对照,开展撒施、穴施、沟施和混施BJ2101L保水剂对土壤水分、盐分和番茄生长影响的田间试验。结果表明：1）沟施、穴施和混施均显著提高0～80cm土层土壤水分,特别在番茄坐果期较对照提高了12.66%、9.40%和7.50%;2）保水剂可有效抑制土壤盐分的积累,提高番茄幼苗成活率,沟施、穴施、混施和撒施番茄产量较对照提高了37.70%、30.93%、26.35%和12.87%,水分利用效率提高了56.58%、44.98%、32.58%和24.05%。因此,河套灌区番茄生产中保水剂应以沟施为主。     

The role of the earthworm Lumbricus terrestris in the transport of bacterial inocula through soil

Two laboratory experiments were used to investigate the effect of the earthworm Lumbricus terrestris on transport of genetically marked Pseudomonas fluorescens inocula through soil microcosms. The microcosms comprised cylindrical cores of repacked soil with or without earthworms. Late log-phase cells of P. fluorescens, chromosomally marked with lux genes encoding bioluminescence, were applied to the surface of soil cores as inoculated filter paper discs. In one experiment, 5 and 10 days after inoculation, cores were destructively harvested to determine concentrations of marked pseudomonads with depth relative to the initial inoculum applied. Transport of the bacteria occurred only in the presence of earthworms. In a second experiment cores were subjected to simulated rainfall events 18 h after inoculation with lux-marked bacteria at 3-day intervals over a 24-day period. Resulting leachates were analysed for the appearance of the marked bacteria, and after 28 days cores were destructively harvested. Although some marked cells (less than 0.1% of the inoculum applied) were leached through soil in percolating water, particularly in the presence of earthworms, the most important effect of earthworms on cell transport was through burial of inoculated litter rather than an increase in bypass flow due to earthworm channels.     

PAM施用方式对土壤水热及玉米生长的影响

为了探寻PAM在玉米生产中的最佳施用方式,在河套灌区玉米播种时,以不施PAM为对照,研究PAM沟施、混施、撒施、穴施对土壤水分、土壤温度和玉米生长的影响。结果表明:1)在玉米生长的不同时期,PAM都可提高土壤水分,特别是在干旱的玉米抽雄吐丝期、灌浆期具有显著作用;2)PAM可延缓玉米幼苗期、三叶期的土壤温度回升,抑制玉米幼苗生长;3)从玉米拔节期开始,PAM可促进玉米生长,在玉米抽雄吐丝期、灌浆期效果最为显著;4)PAM沟施、混施、撒施、穴施的玉米产量分别较对照提高30.6%、39.3%、40.2%和31.7%,水分利用效率分别提高18.97%、25.43%、29.69%和20.46%,水分产出率分别提高31.36%、40.71%、42.15%和32.32%;5)在河套灌区,PAM撒施是玉米播种时相对适宜的施用方法。     

Influence of paclobutrazol on photosynthesis rate and dry matter partitioning in the apple tree

Four‐year‐old ‘Aki Fuji’ apple trees in their second leaf of fruiting were used to study the influence of paclobutrazol on photosynthesis rate (Pn) and the partitioning of dry matter in the different parts of the tree. It was found that the Pn of paclobutrazol‐treated trees was significantly higher than the untreated check trees. This is partially accounted for by the higher light intensity in the canopy of the paclobutrazol‐treated trees. Production efficiency of the paclobutrazol‐treated trees was 2.6 times higher than that of the untreated check trees. Paclobutrazol significantly changed the partitioning pattern of dry matter in the different parts of the tree. A much higher percentage of total dry matter was distributed to the fruit. However, a higher percentage of dry matter was found in the root of the paclobutrazol‐treated trees than in the untreated trees, the difference being mainly in the lateral and fibrous roots. Total dry matter accumulated per m² of occupied land of the paclobutrazol‐treated tree was 4% greater than that of the untreated check trees, whereas total dry matter accumulated per kg of leaves was essentially the same in both trees. Whether calculated on the basis of per m² of occupied land or per kg of leaves, the dry matter distributed into the fruit and into the root was considerably greater in the paclobutrazol‐treated trees than the untreated trees.     

Paclobutrazol effects on soil microorganisms

The side effects of paclobutrazol, a plant growth regulator, on soil microbial community and activity were assessed in soil samples from Petrolina (PE), Pernambuco State and from Lins (SP), São Paulo State, in Brazil. The first experiment was carried out with soils from mango orchards of Petrolina, subjected to frequent field applications of paclobutrazol. A second experiment was conducted with soils from Petrolina and Lins with application of paclobutrazol under greenhouse conditions. For orchard soils, plate counting of soil microorganisms was carried out, while for the greenhouse experiment the parameters evaluated were: microbial biomass C, living hyphal length, dehydrogenase activity, and paclobutrazol dissipation. The paclobutrazol addition to soils of mango orchards in Petrolina, affected negatively the soil microbial community. The average values for total number of bacteria, fungi and actinomycetes were reduced by 58, 28, and 28%, respectively, compared to the paclobutrazol unamended soil. For the greenhouse experiment, the paclobutrazol application in the soils from Petrolina influenced negatively the dehydrogenase activity and the living hyphal length, but not the microbial biomass C. The addition of this substance to the Lins soils had no effect on the microbial parameters evaluated.     

The Contribution of Foliar Exposure to Boron Toxicity

Boron toxicity is commonly considered in terms of plant B uptake and accumulation. This work tested the hypothesis that foliar exposure of water with high B content leads to more severe toxicity reactions in plants as compared to exposure to high B simply through the soil solution. Growth and B uptake were studied in corn, tomatoes, onions, celery and radish where B laden water was applied with and without a component of foliar contact. Increased visual symptoms of B toxicity and decreased yields were found in plants with foliar applied B for all of the crops, while associated increased B tissue concentrations were not measured. The results imply that the relative toxicity of B entering through the leaves is greater than that of B entering via roots. Biomass reduction due to B was found to be a function of neither absolute B accumulation nor relative B mobility in the plant.     

农药在土壤中迁移的区域差异研究

建立了一个基于三种农药在土壤中根区和中间渗流区迁移能力的模型,并采用不同类型土壤分布区域的土壤理化性质,区域气候与水文特以及农药理化性质等参数,进行了农药对区域地下水潜在污染能力的评价。     

Improvement of water application efficiency by moisture conservation methods for establishment of planted tree seedlings

Abstract

The survival rate of transplanted tree seedlings in the afforestation and reforestation programs of Ethiopia has been very often low due to, among others, inadequate soil moisture particularly during the establishment period. Irrigation of seedlings and conserving moisture at the early stage of growth in areas with inadequate rainfall can improve survival. The efficiency of water application can be improved not only through technical and technological consideration of the irrigation hardware (equipment and structures), but also through the application of appropriate soil water management practices. The principles underlying soil moisture movement under different soil conditions were applied on improvement of irrigation application efficiency for the establishment of transplanted tree seedlings at Alemaya Research Station. The principle that a coarser soil layer underlying a given soil prevents, in an unsaturated condition, its penetration by the moisture front, was used in Acacia saligna seedlings. This method of moisture conservation using a sand layer was also tested in combination with surface and vertical organic mulching. Three liters of water was applied to the individual seedlings planted in 2×2 m at a four‐day interval. A higher flesh biomass yield, plant height, and collar diameter were observed using the sand layer. Surface mulching used in combination with sand layer showed the highest value. The soil moisture content measured at 20 cm and 40 cm of the root depth was lower in the control treatment of tree seedlings without sand layer and mulching.     

施用硼肥对杏树落花落果的影响

Effect of boron on falling of prunes (Prunus mune,Sieb,et Zucc) was studied by applying 50g borate per tree into soil on december 15,1993(soil-B) and spraying leaves leves evenly twice with 1.5g kg^-1 borate solution on March 1 and 8,1994(spray-B) on the soil with 0.28mg kg^-1 rapidly available B.Compared with no borate treatment (CK),B concentrations of leaves,short branches and flowers were higher and the percentage of flower and fruit drop was lower in the treatments of soil-B and spray-B.B fertilizer increased B concentrations in flowers,leaves and short branches,promoted pollen germination,reduced the percentage of fall of flowers and fruits of prunes,increased the percentage of fertile fruits,and thus increased yields of prunes by 46% and 34.3% in the treatments of soil-B and spray-B,respectively.It could be inferred preliminarily that if B concentration of leaves was lower than 35 mgkg^-1,the prunes should be fertilized with B.The measured leaves should be picked from branches(3-10cm in legnth)germinating from the central section of a tree crown during the last ten days of May to the early days of June.