Optimization of sowing date and seeding rate for high winter wheat yield based on pre-winter plant development and soil water usage in the Loess Plateau,China

Sowing date and seeding rate are critical for productivity of winter wheat(Triticum aestivum L.).A three-year field experiment was conducted with three sowing dates(20 September(SD1),1 October(SD2),and 10 October(SD3)) and three seeding rates(SR67.5,SR90,and SR112.5) to determine suitable sowing date and seeding rate for high wheat yield.A large seasonal variation in accumulated temperature from sowing to winter dormancy was observed among three growing seasons.Suitable sowing dates for strong seedlings before winter varied with the seasons,that was SD2 in 2012–2013,SD3 in 2013–2014,and SD2 as well as SD1 in 2014–2015.Seasonal variation in precipitation during summer fallow also had substantial effects on soil water storage,and consequently influenced grain yield through soil water consumption from winter dormancy to maturity stages.Lower consumption of soil water from winter dormancy to booting stages could make more water available for productive growth from anthesis to maturity stages,leading to higher grain yield.SD2 combined with SR90 had the lowest soil water consumption from winter dormancy to booting stages in 2012–2013 and 2014–2015; while in 2013–2014,it was close to that with SR67.5 or SR112.5.For productive growth from anthesis to maturity stages,SD2 with SR90 had the highest soil water consumption in all three seasons.The highest water consumption in the productive growth period resulted in the best grain yield in both low and high rainfall years.Ear number largely contributed to the seasonal variation in grain yield,while grain number per ear and 1 000-grain weight also contributed to grain yield,especially when soil water storage was high.Our results indicate that sowing date and seeding rate affect grain yield through seedling development before winter and also affect soil water consumption in different growth periods.By selecting the suitable sowing date(1 October) in combination with the proper seeding rate of 90 kg ha–1,the best yield was achieved.Based on these results,we recommend that the current sowing date be delayed from 22 or 23 September to 1 October.

Effect of Irrigation System, Tillage System, and Seeding Rates on Wheat (<i>Triticum aestivum</i>L.) Growth, Grain Yield and Its Water Consumption and Efficiency

A field trial was conducted at a private farm in AL-Hashimiya district Babylon Governorate—the republic of Iraq during the 2016-2017 and 2017-2018 growing seasons. This study was conducted using two irrigation methods, sprinkler and surface irrigation, for each of them had three Tillage methods (zero-tillage, medium-tillage, deep-tillage) and each tillage system had four seeding rate of wheat yield (120, 180, 240, 300) kg∙ha-1. Results indicated that the consumptive water use was 557.5 and 535.9 mm for surface irrigation and 460.9 and 442.6 mm for sprinkler irrigation in the 2016-2017 and 2017-2018 growing seasons. Sprinkler irrigation significantly increased the flag leaf area with no significant effect on plant height. However, the minimum tillage and seeding rate (240 kg∙ha-1) significantly increased the plant height and flag leaf area in both growing seasons. For the grain yield, the sprinkler irrigation, minimum tillage, and seeding rate (240 kg∙ha-1) also increased the plant height and flag leaf area by 13%, 10, % 11%, 11%, 12%, and 14% in both growing seasons, respectively, through an increased number of spikes/m2, the number of grain spike-1, and 1000-grain weight in both growing seasons, respectively. Interestingly the grain yield was increased by 33% and 32% in both growing seasons under the effects of these three factors altogether, respectively. It can be concluded that these factors act synergistically, resulting in a significant improvement in the wheat grain-yield of, less consumptive water use, and high water use efficiency.

Delayed sowing can increase lodging resistance while maintaining grain yield and nitrogen use efficiency in winter wheat

Lodging resistance of winter wheat(Trnticum aestivum L.) can be increased by late sowing.However, whether grain yield and nitrogen use efficiency(NUE) can be maintained with delayed sowing remains unknown. During the 2013-2014 and 2014-2015 growing seasons, two winter wheat cultivars were sown on three dates(early sowing on October 1, normal so,wing on October8, and late sowing on October 15) to investigate the responses of lodging resistance, grain yield,and NUE to sowing date. No significant differences in lodging resistance, grain yield, or NUE between early and normal sowing were observed. Averaging over the two cultivars and years,postponing the sowing date significantly increased lodging resistance by 53.6% and 49.6%compared with that following early and normal sowing, respectively. Lodging resistance was improved mainly through a reduction in the culm height at the center of gravity and an increase in the tensile strength of the base internode. Late sowing resulted in similar grain yield as well as kernel weight and number of kernels per square meter, compared to early and normal sowing.Averaging over the two cultivars and years, delayed sowing resulted in a reduction in nitrogen uptake efficiency(UPE) by 11.0% and 9.9% compared to early and normal sowing, respectively,owing to reduced root length density and dry matter accumulation before anthesis. An average increase in nitrogen utilization efficiency(UTE) of 12.9% and 11.2% compared to early and normal sowing, respectively, was observed with late sowing owing to a reduction in the grain nitrogen concentration. The increase in UTE offset the reduction in UPE, resulting in equal NUEs among all sowing dates. Thus, sowing later than normal could increase lodging resistance while maintaining grain yield and NUE.

Planting Date, Seeding Rate, and Cultivar Impact Agronomic Traits and Semolina of Durum Wheat

Durum wheat (Triticum durum Desf.) is a market class of wheat subject to price discounts in the marketplace if quality standards are not met. This study was conducted in order to determine how certain agronomic practices might impact durum wheat quality. The effects of planting date (PD), cultivar, and seeding rate on agronomic and semolina quality traits were investigated in field trials conducted near Hettinger and Minot, ND in 2014 and 2015. The interaction of PD and cultivar was significant for many of the traits evaluated. There was a significant PD X cultivar interaction or PD and cultivar effect for yield in all environments. Planting date X cultivar interacted for test weight at all environments. In general, a delay in PD resulted in a significant decrease in yield and test weight for all cultivars. However, Carpio yielded more than other cultivars in high yielding environments while the yield and test weight of Joppa was more adversely affected by delays in PD. Seeding rate did not have a consistent effect on any agronomic or quality trait. Protein content, kernel yellow pigment content, falling number (FN), and vitreous kernels were more dependent on cultivar, regardless of PD and environment. Semolina extraction, gluten index (GI), and wet gluten (WG) values tended to decrease with a delay in PD. These data continue to support cultivar selection as a critical component for obtaining high-yielding, high-quality durum wheat. However, PD and environment can impact certain agronomic and end-use traits, regardless of cultivar grown.

Effect of row spacing and direction of sowing on yield and yield attributing characters of wheat cultivated in Western Chitwan, Nepal

A field experiment was conducted to study the growth and productivity of wheat as affected by row spacing and direction of sowing at Rampur, Chitwan, Nepal during the 2007-2008 wheat growing season. The experiment was carried out in 3-factors factorial randomized complete block design comprising two varieties (Gautam and BL-2800), three row spacings (15, 20 and25 cm) and two row directions of sowing (east-west and north-south). The effects of variety and row direction of sowing on grain yield were significant (p < 0.05), but the grain yield was not affected by the row spacing treatment. BL-2800 variety produced higher grain yield (3.53 t·ha-1) as compared to Gautam (3.11 t·ha-1). Both wheat varieties yielded about 11% higher (p < 0.05) grain in the north-south sowing as compared to the eastwest sowing.

Comparison of yield performance between direct-seeded and transplanted double-season rice using ultrashort-duration varieties in central China

Labor scarcity requires double-season rice to be planted by direct seeding as an alternative to transplanting. Only ultrashort-duration varieties can be used in direct-seeded, double-season rice(DSD) in central China where thermal time is limited. Whether ultrashort-duration varieties grown in DSD can be as productive and efficient in nitrogen(N) use as transplanted double-season rice(TPD) remains unclear. Field experiments were conducted in Hubei province, central China with two establishment methods(DSD,TPD) and three N rates in the early and late seasons of 2017 and 2018. Nitrogen treatments included zero-N control(N0), total N rate of 60 kg N ha;with equal splits at basal, midtillering, and panicle initiation(N1), and weekly N application at 15 kg ha;from seeding/transplanting to heading(N2). Both early-and late-season rice under DSD matured within 95 days, on average 9 days shorter than rice under TPD. The grain yield of DSD was comparable to or higher than that of TDP in both seasons, although the daily yield was significantly higher under DSD than under TDP. Before heading, DSD had higher leaf area,stem number, intercepted radiation, and radiation use efficiency than TPD, which compensated for the negative effect of short growth duration on biomass production. Total dry weight and harvest index under DSD were comparable to or higher than those under TDP. In general, the recovery efficiency of fertilizer-N under DSD was higher than that under TPD, but the reverse was true for physiological N use efficiency. Thus, there was no significant difference in agronomic N use efficiency between DSD and TPD. These results suggested that DSD with ultrashort-duration varieties is a promising alternative to TPD in central China for maintaining high grain yield and N fertilizer use efficiency with less labor input.

播期和播量对小麦临农4357生长发育及产量的影响

以小麦新品种临农4357为材料,采用播期和播量二因素裂区设计,2021—2023年在山西省襄汾县燕村试验田研究小麦生育进程、小麦群体构成、籽粒产量及产量构成因素的变化规律,以明确播期和播量对该品种的群体结构、籽粒产量及产量构成因素的影响。结果表明,随着播期的推迟,临农4357各生育时期均相应延后,且全生育期时间有所缩短;而播量的增减对小麦的生育期则无显著影响。随着播期的推迟,各生育时期的茎、穗数逐渐减少,且差异显著;随着播量的增加,各生育时期的茎、穗数则显著增加。播期的推迟导致成穗率上升,而播量的增大则使成穗率下降。在植株形态方面,播期的推迟使得株高降低,穗长变短,结实小穗数减少;而播量的增大则导致株高增加,穗长变短,结实小穗数也减少。不同播期和播量对产量及其构成因素的影响显著或极显著。对于产量构成因素而言,其影响程度大小依次为播期>播期×播量>播量。临农4357的最佳播期为10月7—13日,相对应的适宜播量为195~240 kg/hm^(2)。进一步相关性分析结果表明,千粒质量与籽粒产量之间存在显著正相关关系(r=0.473),成穗数与籽粒产量之间则存在极显著正相关关系(r=0.569)。此外,播量是引起成穗数变化的主要因素,而播期则是影响穗粒数、千粒质量和籽粒产量变化的主要因素。

有机与常规栽培条件下不同春小麦品种产量与品质的差异

为了解有机和常规栽培条件下不同春小麦品种产量与品质形成的差异,进而筛选适宜有机栽培的优质高产春小麦品种,以北方春麦区主栽的10个品种为供试材料,通过大田试验,采用主成分分析与聚类分析相结合的品质-产量综合评价方法,系统分析了有机与常规栽培模式下不同小麦品种籽粒品质和产量的综合表现。结果表明,不同品种间,籽粒产量、籽粒蛋白质品质指标、容重、出粉率和面团流变学特性指标的差异均达显著水平(P<0.05)。与常规栽培相比,有机栽培下10个品种的穗数、穗粒数、千粒重和产量依次降低了15.1%、42.9%、12.5%和21.4%;蛋白质含量、湿面筋含量、沉降值、容重和出粉率分别降低了32.9%、44.0%、52.9%、8.2%和1.0%;吸水率、面团稳定时间、面团形成时间、拉伸面积、面团延展性和最大抗延阻力分别降低了11.5%、36.2%、40.3%、1.0%、20.5%和10.2%。通过主成分分析,从11个品质指标中提取出4个主成分,累计贡献率达到了91.17%,其中贡献较大的指标有蛋白质含量、湿面筋含量、沉降值、拉伸面积、出粉率、最大抗延阻力。根据品质主成分综合得分和产量聚类,在两种栽培模式下筛选出5个兼顾优质和高产潜力的品种,其中龙麦26无论在有机还是常规栽培下,籽粒产量和品质均表现较好,适宜在河套灌区推广种植。

播期对不同穗型冬小麦生长及产量的影响

为提高冬小麦产量,开展播期对不同穗型冬小麦生长及产量影响的研究。本研究以大穗型品种‘泰农18’、中穗型品种‘山农18’和多穗型品种‘红地95’为试验材料,设置9月30日、10月10日、10月20日、10月30日4个播期,对不同播期条件下的株高、叶面积指数、茎蘖数、产量及产量三要素进行测定。结果表明,随着播期推迟,‘泰农18’、‘山农18’、‘红地95’的株高呈下降趋势,叶面积指数、单位面积茎蘖数、穗数、穗粒数、千粒重和产量均呈现先上升后下降的趋势。产量在播期为10月10日时最高,分别为9.38 t/hm^(2)、8.94 t/hm^(2)、9.22 t/hm^(2),播期为10月30日时最低,分别为7.26 t/hm^(2)、7.32 t/hm^(2)、7.74 t/hm^(2),比最高处理分别下降22.6%、18.1%、16.1%。通过对3个品种产量和三要素之间的通径分析可知,播期主要影响大穗型品种‘泰农18’的穗粒数,中穗型品种‘山农18’的千粒重,多穗型品种‘红地95’的单位面积穗数。综合比较,3个品种的最适播期均为10月10日,晚播可造成株高、叶面积指数、茎蘖数下降,产量降低。

拔节期和花后渍水对不同品种小麦产量及相关农艺性状的影响

为给小麦抗逆高产栽培提供参考,以22个小麦品种为材料,于2018—2019和2019—2020年度分别开展拔节期和花后渍水处理,以自然生长条件为对照,分析渍水对籽粒产量及其相关农艺性状的影响,筛选耐渍高产品种并明确其耐渍高产机制。结果表明,拔节期和花后渍水处理造成小麦籽粒产量分别下降29.6%~59.1%和7.9%~49.1%,均显著降低穗粒数、千粒重、花后干物质积累量和乳熟期LAI。根据两年度不同水分处理下平均籽粒产量和渍后产量的降幅,筛选出相对高产耐渍品种扬麦25及耐渍性较突出品种宁麦22和生选6号。相关性分析表明,不同水分处理下穗粒数、乳熟期LAI、旗叶RuBPCase活性以及花后和成熟期干物质积累量与籽粒产量均呈显著正相关。渍水处理下穗粒数降幅、千粒重降幅、花后干物质积累量降幅、乳熟期LAI降幅与产量降幅均呈显著正相关。花后光合面积大、光合速率高的品种,通过多生产光合物质以供应籽粒灌浆,促进产量形成;渍水导致的光合面积减少和物质生产能力降低是制约高产稳产的关键因素。因此,渍水胁迫下改善小麦生育中后期叶片光合生产能力,尤其是绿叶面积,有助于降低穗粒数和千粒重的渍后降幅;渍水条件下高叶片光合生产能力和穗产量可作为高效筛选高产耐渍品种的依据。

播种期和密度对冬小麦品种河农822产量形成的影响

为给在近年冬前积温增加的情况下冬小麦的种植选择适宜的播种期和密度组合，以河农822为材料，于2006～2007年度在河北省藁城市进行了播种期（10月7日、13日和19日）和密度（基本苗180万、300万、420万和540万／ha）二因素裂区试验，研究了不同播种期和密度条件下小麦的产量及其构成状况。结果表明，播种期只对生育前期总茎数的影响显著，而密度对各生育时期总茎数的影响都显著。播种期对3个产量构成因素（穗数、穗粒数、千粒重）的影响均不显著，但对籽粒产量的影响显著。密度对产量及3个产量构成因素的影响均达到显著水平。播种期与密度对单位面积穗数、穗粒数和籽粒产量存在显著交互作用。3个播种期中，10月7日播期的平均产量显著高于10月19日的，但与10月13日播期的差异不显著。不同密度之间，300万、420万和540万／ha3个水平相互间的平均产量无显著差异，但均极显著高于180万／ha的产量。根据各播种期与密度组合的产量分析，10月7日为最佳播种期，其适宜密度为基本苗300万／ha；10月7日至13日为较适宜播种期范围，其相应的适宜密度为300万～420万／ha基本苗。

不同生态环境与播种期下小麦籽粒品质变异规律的研究

选用6个不同品质类型小麦品种在4个生态点进行分期播种试验,系统分析了不同生态环境下小麦籽粒产量与品质的变异特征及其与主要气候生态因子间的关系。结果表明:生态点、品种以及地点×品种互作对籽粒产量、千粒重、蛋白质、湿面筋和淀粉含量、沉降值与降落值的影响均达到显著水平;不同播种期处理对产量与淀粉含量的影响达到极显著水平,而播种期×品种互作对千粒重、降落值、淀粉含量及沉降值的效应达到显著水平;地点×播种期×品种互作仅对产量、湿面筋、淀粉含量与沉降值有显著的影响。在4个不同生态点中,南京点的籽粒蛋白质与湿面筋含量最低,但淀粉含量最高;徐州点的产量和千粒重最大;泰安点的蛋白质含量与湿面筋含量最高,沉降值最小;保定点的产量、千粒重最小,但沉降值最大。不同播种期处理下,适播与晚播的籽粒蛋白质含量、湿面筋含量、淀粉含量、沉降值与降落值都显著高于早播,而早播期的产量和千粒重最大。各小麦品种在不同地点与播种期下产量与品质性状的变异中以降落值的变异系数为最大,淀粉的变异为最小。开花至成熟期的日均温与淀粉含量呈线性负相关,与产量、蛋白质和湿面筋含量及降落值呈二次曲线相关关系;日温差与产量和千粒重呈二次曲线相关关系,籽粒蛋白质和湿面筋含量。

播期和密度对冬小麦籽粒产量和营养品质及生理指标的影响

为了研究播期和密度对冬小麦籽粒产量和营养品质及生理指标的影响,以中筋小麦中任1号为材料,在大田条件下进行不同播期和密度试验。结果表明,旗叶展开后0~28 d,早播和适播的小麦叶绿素含量高于晚播,生育后期晚播比早播和适播叶绿素含量高,叶绿素含量在不同密度处理间差异不显著。晚播比早播和适播旗叶平均含氮量分别高7%和4%,旗叶含氮量在不同密度处理间差异不显著。播期对籽粒产量及其构成因素有显著影响,籽粒产量和蛋白质产量以适播处理最高,在不同密度处理间除穗粒数差异显著外,其余均不显著。播期对清蛋白、醇溶蛋白和总蛋白含量有显著影响,对球蛋白和谷蛋白含量影响不显著,总蛋白含量以A2播期处理最高。除球蛋白外,总蛋白及其他组分含量在密度处理间差异均不显著,以B1处理最高。研究结果说明,籽粒产量和蛋白质产量以A2B2处理最高,营养品质以A2B1处理最佳。旗叶展开后21 d时,旗叶叶绿素含量与清蛋白和球蛋白含量呈极显著或显著正相关(r=0.73**,r=0.57*)。

播期和密度对冬小麦豫麦49-198群体性状和产量的影响

为给豫麦49—198大面积推广选择适宜栽培措施，设置播期和密度各3个水平，通过大田裂区试验研究了播期和密度对该品种群体性状、产量及其构成因素的影响。结果表明，通过播期和密度变化可以调控群体性状，最高群体茎数随播期推迟和种植密度减小而下降，早播（10月5日）的最终成穗数较少；最大叶面积指数随播期推迟而下降，孕穗后早播的叶面积指数衰减较快；就花后干物质积累而言，播期间适播（10月12日）〉晚播（10月19日）〉早播（10月5日）。不同播期和密度处理对籽粒产量及其构成因素的影响达显著水平，并且密度对产量构成因素的影响大于播期。3个播期中，适播的产量显著高于早播，但与晚播的差异不显著；密度间以中密度（1957Y／ha）产量最高，低密度（120万／ha）最低，两者差异达显著水平，但中密度与高密度（270万／ha）的产量差异不显著。根据本试验结果可以得出，豫麦49—198维持最大叶面积指数9．5和干物质积累量21000kg／ha左右时，籽粒产量可以突破9000kg／ha，相对应的适宜播期和种植密度为10月中旬和195万～270万／ha。

播期推迟对冬小麦产量形成和籽粒品质的调控效应

为了明确推迟播期对小麦产量形成和品质的影响,选用2个冬小麦品种(轮选987和京冬8号),在大田条件下研究了播期推迟对小麦群体动态、物质积累、产量构成和籽粒品质的调控效应。结果表明,播期推迟能显著降低小麦冬前分蘖数,促进春季分蘖的发生和成穗,提高分蘖成穗率。播期对小麦植株干物质积累的影响存在基因型差异。播期推迟引起小麦产量构成因素的变化,进而导致籽粒产量下降,且京冬8号出现显著下降时对应的播期早于轮选987。播期推迟后小麦籽粒中的淀粉含量呈下降趋势,蛋白质含量呈上升趋势,同时二者的主要组成成份也随之改变。因此,冀东地区选用轮选987且适当早播(10月5日播种)可以获得高产;推迟播期至10月10日则籽粒品质提高,但要注意加强小麦生育后期的田间管理,防止粒重明显降低。

播期与密度对冬小麦西农9871籽粒产量的影响

为了研究陕西关中地区小麦播期与密度对产量的影响,采用播期与密度最优试验设计,分析了不同播期与密度处理下冬小麦西农9871产量及产量构成因素的特点。结果表明,小麦产量在7 500~9 750kg.hm-2范围内,适宜的播种期是10月8日至10月20日,播种密度为181万~248万.hm-2。穗值产价、粒值产价、重值产价随着播期的推迟呈现下降的趋势,随着密度的提高而增加。早播情况下低密度分蘖成穗多,但随着播期的推迟分蘖成穗减少,需要加大播种密度,通过提高主茎成穗数来提高小麦产量。粒值产价和重值产价比较大,在成穗数得到保证的前提下,通过增加穗粒数与千粒重能够提高小麦产量。

群体调控与氮肥运筹对强筋小麦济南17号产量和品质的影响

以强筋小麦济南 17号为试验材料 ,选择不同气候、生态条件和地力水平的菏泽市牡丹区和陵县研究播种期、播种量以及氮肥应用对小麦产量和品质的影响。结果表明 ,氮肥的施用时期和施用水平对多项品质性状都有影响。在追肥期的对比研究中 ,起身期追肥产量和有关品质指标都较低 ,综合品质差 ;拔节期以后施肥可有效地提高产量 ,并对改善品质有重要的促进作用。拔节期和孕穗期两次追肥对提高蛋白质含量、湿面筋含量、沉淀值以及面团稳定时间等具有明显的效果。在氮肥用量上 ,各项品质性状均以 75kg/hm2 的纯N处理最差 ,而在 15 0～ 30 0kg/hm2 范围内有利于提高综合品质。通过群体的调控 ,不仅对群体LAI、单位面积穗数、产量有重要影响 ,而且对品质指标如籽粒容重、蛋白质含量、湿面筋含量和面团稳定时间均有显著的作用。济南 17号小麦优质栽培的适宜播种期范围为 9月 2 8日～ 10月 14日 ,最佳基本苗范围为 15 0× 10 4/hm2 ～ 2 2 5× 10 4/hm2 。具有耐大群体的特点 ,但不宜晚播 。

叶面喷施不同营养元素对冬小麦产量和品质的影响

为给叶面施肥在小麦生产中的应用提供技术参考,以不同品质类型的2个小麦品种为试验材料,采用二因素随机区组设计,研究了品种和叶面喷施不同营养元素(硼、锌、锰、铁、磷、钾、氮)对小麦产量和品质的影响。结果表明,在底肥和追肥相同的条件下,品种间产量和品质差异显著。喷施不同营养元素处理的千粒重均比对照有所提高,喷施营养元素处理间产量差异显著,其中叶面喷施硼肥产量最高。叶面喷施营养元素对面团吸水率、形成时间、稳定时间、面包体积、面包评分有显著影响,对籽粒蛋白质含量影响不显著,但对不同蛋白组分有显著影响。叶面喷施铁和锌分别提高了籽粒中铁和锌的含量,但喷锰并未增加籽粒中锰的含量。

主要栽培措施对中筋小麦皖麦44产量和品质的影响

为了给中筋小麦——皖麦44优化栽培提供参考,以此品种为试验材料,研究了播期、密度以及氮肥应用对其产量和品质的调节效应。结果表明,施氮量在0～300kg/hm2范围内,氮素与籽粒产量呈二次曲线关系,与蛋白质含量、湿面筋含量、沉淀值、面粉吸水率、面团形成时间、稳定时间和粉质质量数等呈极显著正相关,与弱化度呈极显著负相关。增施氮素能显著提高蛋白质含量、湿面筋含量、沉淀值和粉质评价值,降低弱化度,延长面团的形成时间和稳定时间。氮肥全部基施和返青追肥产量和品质指标都较低;在拔节期施肥可有效地提高产量,并促进品质改善;在抽穗期施肥能改善粉质性状。皖麦44在淮北地区中等肥力地块的适宜施氮量为150～225kg/hm2,在施足基肥的基础上,追施拔节肥效果更佳。播期和密度对皖麦44的产量有显著影响,对品质作用不明显。

氮肥运筹方式对孕穗期受渍冬小麦穗部结实特性与产量的影响

以小麦品种皖麦54为试验材料,连续两个生长季进行了氮肥运筹方式对孕穗期渍水冬小麦不同小穗位、粒位的结实粒数和粒重影响的观测。结果表明,不同氮肥运筹方式显著影响穗部结实特性,主茎穗结实特性优于分蘖穗。全部基施的氮肥运筹方式较基肥50%+拔节肥50%和基肥30%+拔节肥50%+孕穗肥20%的运筹方式显著增加了不孕小穗数,降低结实小穗数和结实粒数,2008—2010两年度全部基肥运筹方式较基肥30%+拔节肥50%+孕穗肥20%氮肥运筹方式处理不孕小穗数分别增加25.5%和29.8%,结实小穗数均降低5.7%。孕穗期渍水逆境对分蘖穗结实特性影响大于主茎穗,渍水逆境显著增加不孕小穗数,较对照处理,2008—2010两年度,不孕小穗数分别增加10.6%和4.6%;结实小穗数分别降低2.8%和1.4%。孕穗期渍水降低主茎穗结实4粒的小穗数比例和分蘖穗结实3、4粒小穗数的比例及第3、第4粒位籽粒粒重和第3、第4粒位粒重对单穗粒重的贡献率。氮肥后移运筹方式显著提高孕穗期受渍小麦主茎、分蘖穗结实小穗数和粒重,增加主茎和分蘖穗结实3、4粒小穗的比例和结实小穗第3、4粒位的粒重,提高第3、4粒位粒重对单穗粒重的贡献率,减少不孕小穗数,进而较氮肥前移处理显著提高经济产量。氮肥后移运筹方式有利于减轻孕穗期渍害对小麦穗部结实特性的影响。