控失磷钾肥对水稻农艺性状及产量的影响

在早稻上进行不同量控失磷、钾肥与常量控失肥试验。结果表明,在相同条件下,随着磷、钾肥用量的减少,早稻产量也随之下降,但磷肥对早稻产量影响较小,减产幅度为2.5%～5.7%,与常量控失肥处理相比,产量差异不显著;控失钾肥随着用量的减少,早稻产量也下降,减产幅度为4.46%～7.64%,与常量控失肥处理相比,产量差异显著;但与常规肥料相比,减少磷肥用量对早稻产量影响不大,但减少钾肥用量对早稻产量有一定的影响,在比常规钾肥用量减少75%时,早稻减产0.7%。     

氮素对不同大麦品种产量影响的差异性分析

本文以江苏省育成和引进的6个大麦品种为材料,研究参试品种不同施氮水平和不同氮运筹方式对产量影响的差异性。结果表明:江苏省现有啤酒大麦产量存在遗传差异,合理的氮肥用量和运筹方式对产量影响较大,所有参试品种中,以苏啤3号产量为最高,其次为扬饲麦3号和扬农啤2号。     

氮肥运筹方式对大麦产量及其构成因素的影响

在大麦生长发育的关键时期 ,追施适量氮肥以满足其对营养的需求 ,有利于个体稳长不衰和籽粒产量的形成。但氮肥运筹方式不同所产生的作用方向和效果也不同 ,最终使穗粒结构改变而影响籽粒产量的表现。本研究旨在分析大麦产量及其构成因素对等量氮肥分次追肥的反应 ,探讨大麦获得高产优质的合理氮肥运筹方式 ,供大麦生产应用。1　试验设计和方法试验于 1 997～ 2 0 0 0年度在建湖县冈东镇一农户承包地内进行。试验地土质轻壤 ,前茬黄豆 ,中上等肥力水平。供试大麦品种为二棱偏春性、啤饲兼用型苏引麦 1号。播种期 1 0月 1 8～ 2 2日 ,播种量 …     

优质啤酒大麦华大麦6号综合栽培措施的数学模型及优化方案

为给高产优质啤酒大麦新品种华大麦6号的大面积推广提供依据,以五元二次回归正交旋转组合设计为基本数学模型,重点研究了华中地区种植密度、有机肥、氮、磷、钾肥用量等因素对华大麦6号产量、粒重和蛋白质品质的综合效应.模型解析发现,在相同栽培条件下,密度、有机肥、氮、磷、钾肥单因子对产量的绝对贡献顺序为氮肥＞有机肥＞密度＞磷肥＞钾肥,对籽粒蛋白质含量的绝对贡献顺序为氮肥＞有机肥＞密度＞钾肥＞磷肥,对千粒重的绝对贡献顺序为磷肥＞钾肥＞有机肥＞密度＞氮肥.计算机模拟寻优表明,当华大麦6号种植密度在191.64万～211.22万株/ha,施有机肥量在19 162～24 409 kg/ha,纯氮量在206.04～242.56 kg/ha,磷肥量(P2O5)在67.30～81.27 kg/ha,钾肥量(K2O)在61.52～88.48 kg/ha条件下时,产量在4 800 kg/ha以上,籽粒蛋白质含量在10%～12%之间,千粒重＞42 g.因此,这些栽培措施的组合可以作为该品种的高产优质栽培技术的推荐方案.     

氮肥用量及运筹对不同啤酒大麦产量和啤用品质的影响

试验以单二大麦、苏啤3号两个大麦品种为材料,研究氮肥用量及运筹对啤酒大麦产量、千粒重和籽粒蛋白质含量的影响。结果表明:(1)随着氮肥施入量的增多,大麦籽粒蛋白质含量不断增加,同一施氮水平下,氮肥后移会导致籽粒蛋白质含量提高。(2)在250 kg/hm2氮水平下,基追比为7:3时,两个品种产量均达到最高,分别为6 833.68 kg/hm2和7 055.91 kg/hm2。(3)施氮量的多少对大麦千粒重有显著影响,同一施氮水平下不同品种籽粒千粒重的差异主要是由品种本身的遗传差异决定的,受氮运筹的影响较小。(4)综合各方面表现,苏啤3号要远远好于单二大麦,大面积生产上应逐步以苏啤3号来替代单二大麦,以提高大麦的产量和品质,从而达到高产高效的目的。     

播期、播种密度及肥料运筹对青稞产量及产量性状的影响

以13个来自西藏不同生态区的青稞(Hordeum vulgare L.var.nudum HK.f.)品种为材料,研究播期、播种密度、肥料运筹及其互作对青稞籽粒产量和产量性状的影响。结果表明:参试青稞品种的籽粒产量与产量性状在品种间、播期间均存在显著(P<0.05)或极显著(P<0.01)差异;春播青稞籽粒产量显著低于秋播(P<0.05)。播种密度和肥料运筹对参试品种籽粒产量影响不显著。每穗粒数在播种密度和肥料运筹间差异显著(P<0.05),千粒质量在肥料运筹间差异显著(P<0.05)。     

品种、土壤钾、肥料钾和土壤pH的互作对大麦产量和品质的影响

在早期的研究中,Newton发现作物种间的钾素含量以及钾与其它阳离子的比例是有差异的.最近的研究表明,水稻品种间对钾的吸收和对钾肥的反应亦不相同.有人在溶液培养的研究中发现,不同大麦品种对钾素吸收速率不同;钾的供应受限时,它们对钾素竞争能力也不相同.本研究旨在明确钾肥对五个大麦品种的产量和品质的影响.     

水稻不同磷肥用量及运筹的验证与肥料利用率研究

通过水稻不同施磷量及运筹试验,探讨对产量及磷肥利用率的影响。结果表明:以每667m2施P2O58kg,即基施P2O550%(4kg/667m2)+倒5叶50%(4kg/667m2)产量最高;同时合理磷肥用量能显著提高磷肥利用率,特别是提高拔节至抽穗期吸磷量是提高水稻产量重要途径;最佳施磷量及运筹,当季磷肥利用率在35%左右,成熟期植株最佳含磷为0.555%,百公斤稻谷吸磷量以1.11kg为最佳。     

不同施肥措施对苦瓜产量和品质的影响

开展不同氮、磷、钾肥水平,不同施肥措施,有机肥不同用量等对苦瓜产量和品质的影响试验。结果表明：平衡施肥是苦瓜生产上经济有效的施肥方法,以尿素645 kg/hm2、过磷酸钙750 kg/hm2、氯化钾405 kg/hm2,有机肥22 500 kg/hm2的平衡施肥方式最佳。结果同时显示,钾肥施用量对苦瓜品质影响较氮肥、有机肥、磷肥影响大。     

水稻不同磷肥用量及运筹的验证与肥料利用率研究

通过水稻不同施磷量及运筹试验,探讨对产量及磷肥利用率的影响。结果表明：以每667m^2施P_2O_5 8kg,即基施P_2O_5 50％（4kg／667m^2）＋倒5叶50％（4kg／667m^2）产量最高;同时合理磷肥用量能显著提高磷肥利用率,特别是提高拔节至抽穗期吸磷量是提高水稻产量重要途径;最佳施磷量及运筹,当季磷肥利用率在35％左右,成熟期植株最佳含磷为0．555％,百公斤稻谷吸磷量以1．11kg为最佳。     

Characterization of starches of proso,foxtail, barnyard,kodo, and little millets

Scanning electron microscope (SEM) pictures of small millet starch granules showed more large polygonal and few small spherical or polygonal granules. The granules of small millets resembled those of rice starch granules. The size of the starch granules ranged from 0.8–10 m. The size of the granules was larger in barnyard millet and smaller in proso millet. Several granules showed deep indentation caused by protein bodies. SEM of starch isolated from 24 hour-germinated kodo millet showed pitting or pinholes at some points due to the attack of amylases (preferentially on bigger granules). Brabender viscoamylograph studies on small millet starches revealed that the gelatinization temperatures ranged from 75.8 to 84.9 ^° C. Barnyard millet possessed lower amylograph viscosity, minimum breakdown, and relative breakdown values when compared to the other small millets.     

Effects of application of nitrogen fertilizer on concentrations of P, K, S, Ca, Mg, Na, Cl, Mn, Fe, Cu and Zn in perennial ryegrass/white clover pastures in south-western Victoria, Australia

Effects of timing and rate of N fertilizer application on concentrations of P, K, S, Ca, Mg, Na, Cl, Mn, Fe, Cu and Zn in herbage from perennial ryegrass/white clover pastures were studied at two sites in south-western Victoria, Australia. Nitrogen fertilizer (0, 15, 25, 30, 45 and 60 kg ha^–1) was applied as urea in mid-April, early May, mid-May, early June and mid-June 1996 to pastures grazed by dairy cows. At Site 1, N fertilizer resulted in a linear increase in P, K, S, Mg and Cl concentrations in herbage and a linear decrease in Ca concentration. For all times of application, concentrations of P, K, Ca, Mg and Cl in herbage increased by 0·0048, 0·08, −0·010, 0·0013 and 0·053 g kg^–1 dry matter (DM) per kg N applied respectively. For S concentration, maximum responses occurred in mid-May (0·012 g kg^–1 DM per kg N applied). At Site 2, N fertilizer resulted in a linear increase in P, S and Na concentrations in herbage, a linear decrease in Ca concentration and a curvilinear increase in K and Cl concentration. The maximum responses for P, S and K concentrations in herbage occurred for the N application in mid-June and were 0·015, 0·008 and 0·47 g kg^–1 DM per kg N applied respectively. For Cl concentration, the maximum response occurred for the N application in early June and was 0·225 g kg^–1 DM per kg N applied. Overall, applications of N fertilizer up to 60 kg ha^–1 did not alter herbage mineral concentration to levels that might affect pasture growth or animal health.     

Milling,functional and thermo-mechanical properties of wheat,rye, triticale,barley and oat

The milling potential of hulled barley, hulled oat, triticale, rye and wheat was studied using a long tempering process and a laboratory four-roller mill. Regardless of the investigated cereal, the results indicated a significant influence (p < 0.05) of volume per surface area ratio on the milling yield and ash contents of the flour. The lowest milling yield was obtained in case of hulled oat. Solvent retention capacity profiles were determined for all investigated whole cereals and flours for predicting the contribution of different polymers to the functionality of samples. For all solvents higher values were obtained for the whole cereals compared to the corresponding flour. Thermo-mechanical properties of the whole cereals and refined flours were also investigated. If in case of wheat the gluten proteins play an essential role on dough behaviour during kneading at 30 °C, in case of triticale, rye, hulled barley and hulled oat, the fibers play a major role as well. Thermo-mechanical properties of starch registered a large variation between cereals and/or flours. The lowest torque value corresponding to starch gelatinization (C3) was registered in case of the hulled oat flour, 1.92 Nm, while the highest value in case of rye flour, 2.65 Nm.     

Evaluation of the enzyme-amplified ELISA for the detection of potato viruses A,M, S,X, Y,and leafroll

Various parameters,e.g. types of microtiter plate for DAS-ELISA (double antibody sandwich-enzyme-linked immunosorbent assay), use of fresh or frozen amplifier solutions for enzyme-amplified-ELISA, and use of sodium diethyldithiocarbamate (NaDIECA) in sample buffer in cocktail-ELISA were evaluated for the detection of potato viruses A, M, S, X, Y and leafroll from potato foliage. Dynatech Immulon immunoplates provided higher readings for all viruses. Fresh amplifier solution in amplifed-ELISA was superior to frozen solutions. Amplified ELISA gave only marginal improvement in the sensitivity over the standard DAS-ELISA. Addition of NaDIECA in sample buffer did not improve the detection of viruses in DAS-, amplified-, or cocktail-ELISA. Cocktail-ELISA can reduce antigen incubation time to as short as 15 min for PVA, PVM and PVX; 1 hr for PVY and PLRV; and 2–4 hr for PVS using pre-coated plates. Although amplified-ELISA is slightly more sensitive than DAS-ELISA for certain potato viruses, it is not suitable for large-scale indexing of potato viruses in Seed Certification Laboratories, in view of the additional steps needed in carrying out this procedure.     

Study of antimicrobial activity of aloevera, chitosan, and curcumin on cotton, wool, and rabbit hair

Aloevera, chitosan, and curcumin were applied in alone and in combination with each others on cotton, wool and rabbit hair by exhaustion method for the assessment of their antimicrobial activity. The antimicrobial activity of these natural ingredients was better in peroxide treated cotton, formic acid treated wool/rabbit hair fibrous substrates than their corresponding intact ones. Aloevera shown better antimicrobial activity than chitosan and curcumin when applied alone and its antimicrobial activity was enhanced by addition of both chitosan and curcumin. The application of aloevera+chitosan+curcumin combination on peroxide treated cotton and formic acid treated wool/rabbit hair fibrous substrate was fast up to twenty five washing cycles.     

Response of permanent and reseeded grassland to fertilizer nitrogen. 2. Effects on concentrations of Ca, Mg, K, Na, S, P, Mn, Zn, Cu, Co and Mo in herbage at a range of sites

The concentration of mineral elements in herbage from permanent swards of mixed species composition (predominantly Agrostis spp., Holcus lanatus, Festuca rubra, Lolium perenne, Poa spp., etc.) was compared with that from sown perennial ryegrass ( Lolium perenne ) at two fertilizer rates (0 and 300kg N ha⁻¹ year⁻¹, both with P and K) and with L. perennel Trifolium repens (at 0 N with P and K). The investigation was conducted over four years at sixteen contrasting sites in England and Wales. Herbage samples for mineral analysis were taken at first and fourth harvests (May and August) each year from plots under 4-weekly cutting. There was a wide degree of variation between sites, particularly for concentrations of Ca, Mg, Na and all trace elements analysed. Herbage from L. perenne reseeds had significantly higher concentrations of Ca, Mg, Na, Co and S, but K, Mo, Zn, Cu and P were generally lower than in the permanent swards. L. perennel T. repens swards had the highest concentration of major cations, but trace element levels were generally intermediate between those for 0 N permanent and L. perenne swards. Fertilizer N reduced concentrations of Ca, Mn, Mo and S, and increased Mg, Na and Zn, with no consistent effects on K, Co and Cu. Herbage at harvest 4, compared with harvest 1, had higher Ca, Mg, Na, Mn, Zn and S. Permanent and L. perenne swards responded similarly to fertilizer N and between harvest dates. Results are discussed in relation to previous reports of botanical and fertilizer effects on mineral concentrations, and the mineral requirements of livestock. Changes in mineral concentration resulting from reseeding permanent swards are considered unlikely to increase mineral-related livestock disorders, and in many cases could be beneficial, though problems might arise on sites where some elements, e.g. Cu and Mg, are low.