Differences in Wheat Cultivar Response to Nitrogen Supply. II: Differences in N-Metabolism-Related Traits

Two-year field trials with winter wheat cultivars Batis and Toronto were conducted in Southern Bavaria, Germany, to investigate the possible causes of cultivar differences in response to N supply varying in total amount and time of application. The results revealed cultivar-related differences in response to N fertilization in all parameters included in this study. Amount and timing of N fertilization was a strong indicator of N uptake into canopies and three phases of cultivar differentiation became apparent. Cultivar differences in N content were most clearly expressed during early growth stages, but distinctive differences in canopy N uptake were observed during later growth stages. Nitrate reductase activity, water-soluble carbohydrates (WSC), and plant nitrate content varied in response to N supply within cultivar-specific patterns that included reversals in cultivar ranking during canopy development, and provided additional indications for elevated intensity of N metabolism in cv. Toronto when compared with cv. Batis. Apart from such differences Batis partially compensated for delayed N uptake in earlier phases during the latter part of grain filling, presumably due to differences in root system development. Cultivar differences in regression of tillering, stand density, grains per ear and grain density (grains m⁻²) on a number of N metabolism-related parameters have been determined. They contribute considerably to the understanding of cultivar differences in grain yield components, as presented in an earlier communication. For 1000 grain weight, least affected from N supply within each year, large differences between years seemed to relate to differences in WSC content observed between heading and flowering, whereas cultivar differences in the level of grain N content and reaction to N supply were more directly determined by differences in N uptake and remobilization, and possibly enhanced by sink limitations of Toronto in grain size development.     

Winter Wheat Cultivar Responses to Fungicide Application are Affected by Nitrogen Fertilization Rate

Foliar fungicides are important management inputs for winter wheat (Triticum aestivum L.) in high-yielding areas of Europe, but their effectiveness may interact with cultivar selection and nitrogen (N) fertilization. No information is available on the potential use of fungicides in reducing yield losses from foliar diseases in Croatia, where wheat crop is extensively grown under low N inputs. Field experiments were conducted during 2000–02 to evaluate the agronomic responses of six winter wheat cultivars to fungicide application (tebuconazol around heading) compared with untreated plots at low (67 kg N ha⁻¹) and high (194 kg N ha⁻¹) N fertilization rates. Grain yields tended to increase in all years following fungicide treatment at high N rate by an average of 10.1 % (773 kg ha⁻¹), but improved significantly in one year only at low N rate. When these occurred, yield increases were associated with larger grain weight per ear primarily due to heavier 1000-kernel weight. Cultivars differed in their responses to fungicide application across growing seasons and N fertilization rates. Under low disease pressure in 2000 and 2001, improved yields with fungicide use occurred for few susceptible cultivars only, whereas all cultivars significantly increased yields under higher disease severity in 2002 by an average of 383 kg ha⁻¹ (5.0 %) at low N rate and 1443 kg ha⁻¹ (19.0 %) at high N rate. Following fungicide application at high N rate, some susceptible cultivars outyielded resistant cultivars, whereas opposite responses occurred in untreated plots. High N fertilization rate consistently produced larger grain yields except under high disease severity and no fungicide sprayed in 2002, when it had no benefits at all over low N rate. Fungicide application showed limited importance for wheat performance at low N rate; however, cultivars significantly differed in yield responses as well as in rankings after fungicide use at high N fertilization rate.     

Analysis of Wheat Cultivar Differences in Grain Yield, Grain Nitrogen Yield and Nitrogen Utilization Efficiency.

More detailed information on the causes of yield variability among wheat cultivars is needed to further increase wheat yield. Field studies were conducted in Northern Greece over the two cropping seasons of 1985—1986 and 1986—1987 to assess the effects of nitrogen fertilizer and application timing of the various component traits that determine grain yield, grain nitrogen yield and nitrogen utilization efficiency of two bread ( Triticum aestivum L.) and two durum ( Triticum durum Desf.) wheat cultivars, using yield and yield component analysis. Nitrogen at a rate of 150 kg ha^-1 was applied before planting or 100 N kg ha^-1 before planting and then 50 N kg ha^-1 top dressed at early boot stage. Nitrogen and cultivars affected all traits examined, while split nitrogen application affected only some of the traits. Grain yields in the most cases were correlated with number of grains per unit area and grain weight and grain nitrogen yields in all cases with grain number per unit area. The contribution of the number of grains per spike to total variation in grain yield among cultivars was almost consistent (37 to 55 %), while the contribution of grain weight was more significant (up to 55 %) in high yields (>6.500kg ha^-1) and number of spikes per unit area (>500). The number of grains per spike contributed from 60 to 83 % to the total variation in grain nitrogen per spike. Increased grain nitrogen concentration resulted in a reduction of its contribution in grain nitrogen yield variation. Nitrogen utilization efficiency was higher during grain filling than during vegetative biomass accumulation. The contribution of nitrogen harvest index to the variation of utilization efficiency for grain yield was higher in plants receiving nitrogen application.     

氮肥实时监控技术对冬小麦产量及养分效率的影响

为了高效利用氮肥,通过2005-2007年定位试验,应用氮素实时监控技术研究小麦最佳施氮量。结果表明,推荐的施氮量与农户习惯施氮量相比,氮肥的施用量大幅减少,3年累积节约氮肥投入903 kg/hm2。由于该技术实现了氮肥供应与小麦需求的同步,因此,产量较农户习惯施氮增加6.1%,收益增加1833元/hm2,同时,氮肥的利用效率、农学利用率以及偏生产率显著提高,而土体硝态氮的累积与淋洗则大幅下降。小麦应用氮素实时监控技术,可以实现产量增加、养分效率提高及生态环境保护的协调一致。     

Effects of Benzyl Adenine and Abscisic Acid on Grain Yield and Yield Components in Triticale and Wheat

Grain yield and yield components (grains per ear, grain weight, 1000-grain weight, ear weight, ear seed ratio and dry matter partitioning between ear and seed) were examined in a wheat genotype (PBW-343) with well-filled grains and a Triticale genotype (DT-46) with poorly filled grains (showing grain shrivelling) grown in pots. Six days after anthesis (DAA), benzyladenine (BA) @2 µg ear⁻¹ and abscisic acid (ABA) @4 µg ear⁻¹ were injected at the base of the mother shoot ear in both species. It was observed that, in both wheat and Triticale , BA increased the grain weight, grain number and partitioning of dry matter between ear and seed, whereas ABA decreased the grain weight, grain number and dry matter partitioning between ear and seed. However, these decreases were slower in Triticale than in wheat. BA treatment increased the grain dry matter accumulation, which in turn resulted in better filling of grains and increased the grain weight in both wheat and Triticale . The average grain weight of Triticale was lower than that of wheat. Thus, it appears that variation in grain weight between wheat and Triticale might be due to different availabilities of growth-promoting phytohormones such as cytokinins and assimilates.     

耕作和培肥对豫中区冬小麦生长和产量性状的影响

以‘百农矮抗58’为试验材料,在2007-2008年度深耕土壤的基础上,于2008-2009年度研究了深耕（耕深40 cm）和浅耕（耕深20 cm）2种耕作方式和底施专用复合肥（B1）、专用复合肥+鸡粪（B2）及专用复合肥+饼肥（B3）3种培肥模式对豫中区冬小麦生长和产量性状的影响。结果表明：浅耕模式下小麦的株高、群体数量、叶片叶绿素含量及地上部单株干物质积累量均高于深耕模式。B3培肥模式下,小麦叶片的叶绿素含量和植株地上部分干物质积累量较高。浅耕+B3模式下成穗数和穗粒数极显著高于其它模式,产量较高。综上,深耕基础上,浅耕配施复合肥和饼肥是豫中区适宜的种植模式。     

Response of Triticale Grain Yield and Yield Components to Number of Cuttings in a Mediterranean Environment

In six field experiments conducted over 2 years, the effect of one or two cuttings on grain yield of triticale (× Triticosecale Wittmack) were investigated. In addition, the relationships between triticale grain yield its components were analysed.
Grain yield of the uncut plots invariably exceeded the plots with one or two cuttings, regardless of the environment or year. The reductions in grain yield caused by one cutting ranged from 27 % to 60 % under rainfed conditions and 18 % to 20 % under irrigation. With two cuttings the reduction was 45 % to 70 % for rainfed, and 35 % to 48 % for irrigated conditions.
The yield components which most influenced grain yield of triticale under cutting treatment were the number of ears m⁻² in all six experiments and the number of grains per ear under rainfed conditions. At the rainfed sites in 1989 cuttings diminished the number of ears m⁻² mainly by increasing plant mortality. Nevertheless, at the rainfed sites of 1990 and at the irrigated site of both years, the reduction in the number of ears m⁻² with cuttings was due principally to a lower survival of tillers per plant.     

微量元素喷施对冬小麦籽粒产量和品质的影响

通过对不同生育期小麦叶面喷施不同浓度微量元素,探究冬小麦对微量元素的吸收和利用.采用大田试验,设置1倍(B1)、50倍(B2)、100倍(B3)和500倍(B4)四个浓度处理(等量水为对照),喷施时期为苗期(A1)、苗期+拔节期(A2)、苗期+拔节期+扬花期(A3)、拔节期(A4)、拔节期+扬花期(A5)和扬花期(A6...     

冬小麦田间水分反应特性产量评价指标研究

摘要：【目的】为全面有效地评价冬小麦品种对水分的反应特性。【方法】根据2007年和2008年不同小麦品种大田灌水试验的结果分析了抗旱系数(DC)、抗旱指数(DRI)、干旱产量指数(DYI)、丰水产量指数(WYI)、产量-水分高效利用指数(YWI)、水分适宜指数(WAI)和产量系数(YC)的适用性。【结果】DC反映品种的水分敏感性;DRI适合筛选旱地产量高且灌水增产不显著的品种;DYI较好的反映干旱条件下的产量,WYI能够反映不同品种的灌水效率差异,YWI适合筛选干旱条件和灌水条件下产量较高的种质。WAI适合参试品种间相对比较,但对同一品种适水性的评价效果因品种而异。产量系数(YC)适于组内筛选抗旱品种、高产品种和某灌水条件下水分高效型品种。【结论】初步提出多指标评价品种水分反应特性的方法和统一的分级标准。提出在合理选用对照种和明确水分鉴定条件的前提下,采用干旱产量指数修订值鉴定品种的抗旱性,用丰水产量指数修订值鉴定各水分条件下品种的水分高效性,用各水分条件下品种的平均产量相对值鉴定品种的高产性,采用阶段敏感指数鉴定不同生育期的水分敏感性,采用产量系数修订值鉴定品种的适水性。     

播种期和种植密度对小麦新品种豫农202产量构成的影响

合理的播种期和种植密度有助于挖掘小麦品种的产量潜力。利用裂区试验研究了播种期和种植密度对小麦新品种豫农202产量及其构成因素的影响。结果表明：播种期对小麦新品种豫农202的产量及其构成因素影响较小,除对穗数的影响达显著水平外,其它均不显著。种植密度则影响较大,除对千粒重的影响不显著外,其它均达到显著或极显著水平,特别是对穗数和穗粒数影响的显著程度非常高。在不同的播种期下各种植密度间产量差异较大,但产量构成因素差异较小。在不同播种期和种植密度下,穗数对产量的直接影响较大,其次是穗粒数,千粒重的直接影响很小。该品种的适宜播种期应该在10月8日至10月25日,早播情况下选择120万/ hm2基本苗较合适,中晚播情况下选择240万/ hm2。     

豫北地区冬小麦生产对气温变暖的响应

利用豫北地区沁阳市农气站1981-2010年气温资料和1984-2010年冬小麦观测资料,采用统计和相关性分析方法,研究该地区冬春季极端气温、冬小麦物候期和产量构成因素的变化以及该区域冬小麦生长对冬春季极端气温变化的响应。结果表明,近30年来,豫北地区冬、春季平均最低气温增温速率分别为1.4℃/10年和1.3℃/10年,冬季增温速率较高;冬季平均最高气温的变化趋势不明显,春季平均最高气温升高显著,其增温速率为0.7℃/10年。冬小麦返青期的年际变化趋势不明显,抽穗期和成熟期分别以4.0天/10年和2.9天/10年的趋势显著提前,抽穗期提前的趋势较大,全生育期天数以4.6天/10年的趋势显著缩短。冬小麦有效穗数的变化趋势不明显,但穗粒数以4.4粒/(穗?10年)的速率显著减少,千粒重以4.9 g/10年的速率明显增加。相关性分析表明,冬季平均最高气温每升高1℃返青期提前2.7天;春季平均最高气温和最低气温每升高1℃抽穗期分别提前2.8天和3.4天,成熟期分别提前2.6天和2.5天,全生育天数分别缩短3.5天和3.6天。冬季平均最低气温每升高1℃有效穗数和穗粒数分别减少20.5穗/m2和2.4粒/穗;春季平均最高气温每升高1℃千粒重增加2.0 g;千粒重与春季平均最低气温呈抛物线关系,当最低气温超过13℃时,千粒重开始下降。豫北地区近30年来冬春季极端气温变暖的趋势明显,该区域极端气温变暖对冬小麦生产的影响较为显著。     

Effects of Temporary Water Stress After Anthesis on Grain Yield and Yield Components in Different Tiller Categories of Two Spring Wheat Varieties

Water stress might limit grain yields of cereals under humid conditions. The objective of this study was to investigate the effect of a temporary water shortage at three different stages after anthesis on the grain yield and yield components of different tiller categories in two spring wheat varieties. A pot experiment with controlled water supply and rain shelters was conducted in 1984 and 1985 in Kiel, N. W. Germany. The water stress (pF 2.9 to 3.4) was imposed either between anthesis to early milk development of the caryopsis (WS1) (EC 65 to EC 72 according to Z adoks scale), early milk development to late milk development of the caryopsis (WS2) (EC 72 to EC 77) and late milk development to maturity (WS3) (EC 77 to EC 92). The control had a constant water supply throughout the growing season of between pF 2.2 to 2.5.
The water stress treatment WS1 significantly reduced the single plant yield by 10 % (1984) and 15 % (1985) in one variety (Selpek), whereas the other variety was unaffected. The response of both varieties to the two later treatments was smaller and insignificant.
In the first year the yield decrease in the variety Selpek after the WS1 treatment was mainly caused by a lower number of ears per plant compared with the untreated control (WS0). In the second year (1985) additionally a lower grain weight of the second category shoots caused by a reduction of the number of kernels per ear contributed to the decrease of the single plant yield. The yield component thousand grain weight could not compensate for the reduction in the number of kernels per ear.     

分层供水施磷对冬小麦磷效率及产量的影响

研究分层供水施磷对冬小麦磷效率及产量的影响,为指导旱地施磷提供一定理论和实践依据。试验设整体湿润(W1)和上干下湿(W2) 2 种水分处理,不施磷(CK)、表施(SP)、深施(DP)3 种施磷处理,供试品种选用水分敏感型（‘小偃22’）和抗旱型（‘长旱58’）。研究结果表明：磷肥施用深度对冬小麦磷根效率比、磷肥利用效率、磷肥偏生产力(PFPP)及产量的影响随土壤水分和品种而异。2 种水分条件下,‘小偃22’DP较SP处理磷肥利用率、PFPp均显著降低(P＜0.05),磷根效率比及产量则差异不显著;W1 处理下,‘长旱58’DP较SP处理除磷根效率比外其他指标均显著降低(P＜0.05),W2 处理下则相反,上述指标均显著增加(P＜0.05)。本试验结果表明,土壤水分供应不足时,磷肥深施有利于提高抗旱性较强冬小麦品种对磷素的吸收利用能力,从而提高磷肥利用率及产量。     

Seed Yield and Yield Contributing Characters as Influenced by N Supply in Rapeseed-mustard

Brasisca Juncea , cv. Pusa Bold, and B. campestris , cv. Pusa Kalyani, were raised under field conditions with varying levels of N supply from 0–120 kg ha^-1. The production profile of branches and pods thereon was measured, per unit area basis, throughout the crop ontogeny. At maturity, data on the yield contributing characters, viz. pod dry weight, pod number, seed number per pod, 1000 seed weight, seed wall ratio and seed yield in different order branches, was recorded.
The branching pattern and the number of pods produced on different order branches, in the two species, was favourably modified by the increasing levels of N supply. Primary and secondary branches contributed to the seed yield to an extent of 80 % of the total yield. Nitrogen treatment had no significant effect on 1000 seed weight. B. juncea exhibited significantly higher yield over B. campestris. N supply up to 120 kg ha ^-1 linearly increased seed yield in both the species. However, it exerted a negative effect too partitioning of assimilates from pod wall to seed. The study indicated that rapeseed-mustard, grown under short winter-season environment with adequate soil moisture, has the potential for higher N-fertilizer optima exceeding 120 kg ha ^-1.     

Effect of Varied N-fertilization on Yield Formation of Winter Wheat under Particular Consideration of Mainstems and Tillers

Two-year field trials with winter wheat in nine N-fertilizer treatments were conducted in southern Bavaria to investigate the basis of yield stability and yield superiority of N-fertilization strategies with emphasis on N-application during stem elongation. In measurements of individual plants the contribution of mainstems and tillers to yield formation was examined. While grain yield showed only slight differences, significant differences between harvest indices were observed among the fertilizer treatments. High harvest indices were regularly recorded in low stand densities. Individual plant analysis proved that early N-application led to high stand densities which intensified reduction processes during ear development. N-fertilization with emphasis on stem elongation lessened reduction processes. Low yield of tillers was mainly attributed to a low grain number per ear. Differences in grain yield between mainstems and tillers could not be modified by means of N-fertilizer treatment. Highest yields on mainstems as well as on tillers were recorded in N-fertilizer treatment with emphasis on stem elongation. This study demonstrates that an excessive initiation of yield components causes an unproductive consumption of resources which is detrimental to yield formation. It is concluded that optimum N-fertilizer treatment should aim at plant stands with strong individual plants which can be achieved by emphasis of N-fertilization during stem elongation. The stimulation of the initiation of yield organs is of minor importance as compared to a decrease of reduction process.     

水分运筹对豫北冬小麦生育后期光合特性及产量的影响

为探讨豫北地区冬小麦合理的水分运筹模式,以‘周麦18’为供试材料,设置了全生育期不浇水（CK）、越冬水（W1）、越冬水＋拔节水（W2）和拔节水（W3）4种水分运筹方式,研究了水分运筹对冬小麦生育后期旗叶光合特性及籽粒产量的影响。结果表明,W3处理下,小麦生育后期,旗叶气孔导度和光合速率较高,蒸腾作用和胞间CO2浓度较低。从产量因素来看,W3处理下的有效穗数及穗粒数均较高,最终产量（10183.4 kg/hm2）显著高于其它处理。因此,在豫北地区,足墒播种的基础上,小麦生育期灌拔节水有利于提高籽粒的产量和水分利用效率。     

Response of Wheat Varieties from Semi-arid Regions of Jordan to Salt Stress

This study was carried out to determine the effects of salinity levels (control, 6, 12 and 18 dS m^?1) on germination, seedling growth, some agronomic traits and proline accumulation in leaves of nine wheat varieties adapted to semi‐arid areas of Jordan. The tested wheat materials included eight durum wheat varieties (Haurani 27, Acsad 65, Om Rabbeeh, Sham 1, Safra Ma’an, Katma, Al‐Samra and F8) and one bread wheat variety (Diel Harthon). Final germination percentage, shoot and seminal root length, and all growth and yield parameters were significantly (P < 0.05) decreased by increasing salinity level. Proline content was significantly (P < 0.05) increased by increasing salinity. There were significant variety × salt interactions (P < 0.05) on final germination percentage, seminal root length, grain yield and yield‐related traits indicating that the varieties responded to salt differently. Sham 1 did not show any decrease in germination ability at the different salinity levels. Haurani 27, Acsad 65, Al‐Samra and Diel Harthon showed a nonsignificant reduction in germination potential at low and intermediate salt levels. Safra Ma’an and Al‐Samra showed the lowest reduction in seminal root length at low salt level and consequently exhibited the lowest stress susceptibility index ‘S’ values. Grain yield‐based stress susceptibility index ‘S’ indicated that Haurani 27, Acsad 65, Katma, Al‐Samra, F8 and Diel Jardoon were more salt tolerant than Om Rabbeeh, Sham 1 and Safra Ma’an. In conclusion, a similar salt tolerance was observed at different growth stages in Haurani 27, Acsad 65 and Al‐Samra. Consequently, these three varieties could be considered as salt tolerant and accordingly they are suitable for durum wheat improvement. Furthermore, Sham 1 had the highest ability to germinate at high salinity level indicating that it has a genetic potential for salt tolerance, at least at this stage of its life cycle.     

再生稻种植产量差形成的研究

为明确安徽省沿江地区再生稻种植产量差形成的原因,筛选出该地区适宜的再生稻种植品种,以9个杂交水稻品种为试材,比较分析了其头季和再生季生育期、再生力、产量及其构成因素等性状。结果表明,在产量构成因素中,造成不同品种头季稻产量差异的主要因素是单位面积上的有效穗数;导致再生季产量差异的主要因素是单位面积上有效穗数和每穗着粒数。准两优608再生季单产5.27 t/hm~2,2季综合产量高达13.59 t/hm~2,可作为该地区再生稻种植的优选品种;皖稻119和新两优6号头季产量高,再生力较强,再生季产量潜力大,可以作为该地区再生稻种植的候选品种。研究表明,生产中可通过增加单位面积上有效穗数,主攻大穗,并在维持较高结实率的基础上提高千粒质量以实现再生季产量增加和获得2季综合高产。     

旱地条件下冬小麦产量和农艺性状对养分投入的响应

以9个旱地冬小麦品种为材料,通过田间试验研究其产量及主要农学性状与养分投入水平的关系。与不施肥对照相比,在低、高水平养分投入条件下小麦籽粒产量分别提高20%和40%,生物量提高17%和35%,单位面积穗数增加11%和25%,穗粒数增加8%和10%。高产品种的生物量、单位面积穗数、穗粒数及其随养分投入增加而提高的幅度显著高于低产品种。千粒重不受养分投入水平的影响。旱地条件下,不同小麦品种的产量、生物量、单位面积穗数和穗粒数均随养分投入水平的提高而显著提高,并且存在品种间差异。高生物量、高单位面积穗数和穗粒数是旱地高产品种的重要特征,它们对养分投入的敏感响应是高产品种养分投入提高后产量提高的主要原因。     

不同穗型小麦花后物质运转及产量对氮肥的响应

在大田条件下,以多穗型小麦‘烟农19’和大穗型小麦‘兰考矮早8’两个不同穗型的冬小麦为材料,研究了不同施氮量及氮肥基追比例对小麦营养器官花前贮藏同化物再运转,花后同化物输入籽粒量,产量及产量构成因素的影响。结果表明,氮肥水平在225~300 kg/hm2范围内,多穗型小麦‘烟农19’和大穗型麦‘兰考矮早8’籽粒产量的形成均以花后绿色器官光合同化为主,其次才是花前积累干物质的再动员分配。大穗型品种‘兰考矮早8’籽粒产量的形成较多穗型品种‘烟农19’更依赖于花后绿色器官同化,积累干物质再运转分配只占籽粒产量的15%左右。两种穗型品种小麦花前贮存物质再动员分配对籽粒产量的贡献都随着氮肥后移而降低。随着施氮量的增加,运转物质对籽粒产量的贡献率呈降低趋势。综合物质运转和产量表现,‘烟农19’施氮量300 kg/hm2,基追比例5:5时较适宜;‘兰考矮早8’施氮量262.5 kg/hm2,氮肥基追比例7:3时较适宜。