不同氮、磷、钾肥用量对‘法兰西’西梅产量及土壤养分的影响

在田间条件下,以5年树龄的‘法兰西’西梅树为研究对象,采用‘3414’完全实施施肥方案(N、P2O5、K2O三因素二水平的株施用量分别为0.093、0.017、0.190kg),测定其对‘法兰西’西梅产量及土壤养分的影响,以研究不同氮、磷、钾肥用量对‘法兰西’西梅产量及土壤养分的影响。结果表明:从各因素不同水平比较来看,施氮、磷、钾肥分别比不施氮、磷、钾肥处理‘法兰西’西梅株产量增加0.415~0.937、0.431~1.286、1.507~2.677kg,其中各因素以株施N 0.093kg增产0.937kg、P 0.017kg增产1.286kg、K 0.190kg增产2.677kg最高;根据肥料用量与产量所拟合的方程计算,最高产量的氮、磷、钾肥株施用量分别为0.075、0.015、0.210kg;不同施氮、磷、钾肥用量处理,对应的土壤全氮、全磷、全钾、速效氮、速效磷含量均有明显的增加趋势;说明在合理施用基肥的基础上,合理确定氮、磷、钾肥的施用数量和配比对西梅产业的长期、高效、优质的发展具有重要意义。     

胡葱浸提液对莴苣、小白菜、萝卜和黄瓜化感作用初步研究

以胡葱为供体，以莴苣、小白菜、萝卜和黄瓜为受体，通过种子萌发试验及幼苗生长试验，对 胡葱浸提液的化感作用进行了初步研究。结果表明，胡葱浸提液对莴苣和萝卜种子萌发具有抑制作用， 对小白菜和黄瓜种子萌发影响不大；对莴苣、小白菜、萝卜和黄瓜幼苗生长整体上来说具有一定的促进 作用。     

Preservation of cuttings of Rhododendron obtusum Planch., R. ponticum L. and R. simsii Planch.

Owing to lack of space or time, cuttings of rhododendrons cannot always be rooted at the moment they are ready for propagation. We investigated how cuttings could be cold stored until the time they are to be rooted. The cuttings can best be preserved at temperatures just above freezing. At higher temperatures the period of successful storage is shortened. The greatest hazard is Botrytis cinerea attack, but this can be prevented by a prophylactic spray with benomyl. More lignified cuttings can be preserved longer than more herbaceous ones. The methods described can be used for storing cuttings of Rhododendron obtusum, ponticum and simsii hybrids.     

Aseptic micropropagation of Rhododendron P.J.M. hybrids

Summary

Shoot tips established in vitro better than single nodes. Five-cm shoot tips gave better Stage I results than 2-cm shoot tips. The best microshoot proliferation rates were obtained with isopentenyladenine (2iP) at 5 and 10 mg l^?1; tetrahydropyranyl-benzyladenine was ineffective. Microshoots rooted well, regardless of the level of 2iP in the Stage II medium. Stem-cutting-macropropagated plants generally were more variable in height, had less basal branching and were more erect than plants from microculture.     

Competitive Effects of Three Perennial Weeds,Cynodon Dactylon (L.) Pers., Cyperns Rotundus L. and Sorghum Halepense (L.) Pers., on Young Citrus

One-year-old sour orange seedlings were grown with the perennial weeds Cynodon dactylon, Cyperus rotundus and Sorghum halepense in adjacent containers, which were either separated or linked. In the separated containers no effect due to aerial competition was apparent on citrus after ten months. In the linked containers citrus growing with weeds showed, after 3-4 months, severe reductions in plant height, stem diameter and leaf number. The addition of nitrogen slightly reduced the competitive effects of the weeds. The order of competitive capacity was C. dactylon<S. halepense<C. rotundus. When weed tops were removed, the citrus plants recovered within six months from the most severe damage. It is suggested that competitive effects are caused, at least in part, by phytotoxic substances produced by the weeds.     

Effect of sampling time and soil type on Mn,Fe, Zn,Ca, Mg,K and P concentrations of olive (Olea europaea L., cv. ‘Koroneiki’) leaves

It has been studied the time course of seven leaf nutrients’ (Mn, Fe, Zn, Ca, Mg, K and P) concentrations when plants of the olive cultivar ‘Koroneiki’ were grown for about 5 months (from the 30th of May till the 17th of October) in three soils from different parent materials (Marl, Gneiss schist and Peridotite), located in the region of Central Macedonia, Northern Greece.     

几种物质对蓝莓土壤pH及有效N、P、K的影响

以4年生盆栽"灿烂"兔眼蓝莓为试材,研究了硫磺、硫酸钾和食用醋对土壤pH及有效N、P、K含量的影响。结果表明:在土壤中施入一定量的硫磺、硫酸钾和食用醋后,能显著降低土壤pH,增加土壤有效N、P、K含量。其中食用醋能迅速降低土壤pH至蓝莓生长最适的4.0~4.8范围,硫磺也能调整土壤pH至4.0~4.8,但改良效果较食用醋慢,3种物质中硫酸钾改良土壤pH的效果最差,同时土壤中有效N、P、K含量随pH降低而增加。综合分析表明,食用醋是一种见效快,易于施用的土壤pH改良物质。     

樱桃水状态参数日变化特性的研究

以3年生相同生境西洋樱桃品种"红灯"为试材,通过测定土壤含水量、茎流量、叶片水势、蒸腾速率等指标,研究同一樱桃在不同栽培条件下水状态参数的日变化。结果表明:土壤含水量无论在空间还是时间上,都是随深度和时间的推移而递减,茎流量呈现倒"U"字型曲线,叶片水势呈现"V"字型曲线,蒸腾速率在晴天呈现双峰曲线,土壤含水量、茎流量、叶片水势和蒸腾速率有明显的相关性。     

新型肥料对土壤碳氮及枸杞产量的影响

以4种新型肥料(瑞利源(RLY)、汇源(HY)、中农1(ZN1)、中农2(ZN2))为试材,常规肥料为对照(CK),基于青海省海西州诺木洪和乌兰地区枸杞的施肥试验,研究了不同新型肥料对枸杞根际土壤总碳、全氮以及枸杞产量、品质的影响。结果表明:1)诺木洪试验地,RLY、ZN2处理土壤总碳含量比CK分别提高了4.49%和3.55%;4种处理下土壤全氮含量均小于CK。乌兰试验地,RLY、ZN1、ZN2处理的土壤总碳含量比CK分别提高了2.75%、2.33%和1.71%;土壤全氮含量均小于CK。2)诺木洪各施肥处理样地与CK相比,枸杞产量增幅分别为21.8%(RLY)、23.9%(HY)、12.7%(ZN)、25.4%(ZN2);乌兰各施肥处理样地与CK相比,枸杞产量增幅分别为12.7%(RLY)、9.9%(HY)、1.1%(ZN)、21.1%(ZN2);在诺木洪和乌兰样地,ZN2施肥处理枸杞产量增幅最高。3)诺木洪试验地新型肥料施肥处理未能显著增加枸杞多糖含量,乌兰试验地HY、ZN1、ZN2处理下枸杞多糖含量显著高于CK。