Effect of forage removal at the first detectable node stage on the growth of winter and spring triticale

The effect of forage removal on the growth of five winter and five spring triticale genotypes was studied in 1992 and 1993 in field experiments in north-eastern Spain. When cut, winter triticales produced more biomass and leaf area than spring types owing to their higher tillering capacity. The leaf area index (LAI) at anthesis was similar in both groups in both clipped and uncut plots, but spring triticales had a greater leaf area on the main stem than winter types. Winter types had a greater leaf area on the tillers than spring types. Spring and winter types had a similar physiological response to forage removal, except for modifications in flag leaf area. In spring types triticale flag leaf area was reduced by clipping, whereas in winter types flag leaf area was increased. Forage removal resulted in less dry-matter accumulation in all plant parts, maximum weight of the plant being reduced by about 20% and the rate of growth by around 13%. LAI at anthesis decreased by 37% as a result of clipping, and the leaf area duration from anthesis to maturity decreased by 36%. The duration of growth increased after clipping. Heading, anthesis and maturity dates were delayed by clipping, but grain filling duration was not affected.     

Yield and quality of winter and spring triticales for forage and grain

In field experiments conducted over 2 years in Mediterranean conditions, five winter and five spring triticales were evaluated for forage and grain production in the same cropping season. The experiments had two treatments, namely harvesting for grain only, and dual-purpose forage and grain production. In the latter treatment, forage was cut when the first node was detectable (Zadoks' stage 31), without removing the apical meristems. Grain was harvested when ripe (Zadoks' stage 92) in both cut and uncut plots.
Environmental conditions affected grain production and protein content more than forage yield and quality. Winter triticales yielded about 43% more forage than spring types, but after forage removal the spring types yielded about 36% more grain than winter triticales.
Reductions in grain yield after clipping were more pronounced in winter (32%) than in spring (19%) types. Forage crude protein content was significantly higher in the spring types studied (24.6%) than in the winter types (23.5%), the opposite being true for fibre content (20.7 and 21.6% respectively). Grain crude protein content did not differ between grain and dual-purpose treatments, but was higher in the spring triticales (12.8%) than in the winter types (11.9%). There was more variability for the measured traits within the winter triticales studied than within the spring types.     

Triticale and other small grain cereals for forage and grain in Mediterranean conditions

In field experiments conducted over 2 years, triticale was compared with barley, bread wheat and oats for its dual-purpose (forage and grain) capability.
The effect of spring forage removal on grain yield ranged from small yield increases (in the triticale and barley genotypes that otherwise lodged) to a 53% decrease, and was dependent on species, genotype, stage of development when cut, and time for recovery before grain harvest. A key factor influencing grain yield after early cutting was the number of spikes that developed.
The complete types of triticale were better than the one substituted type tested for dual purpose but, as there is variability among them, selection for good mixed aptitude is possible.
The production of the best triticale averaged over 2 years 3 t of forage DM ha^-1 (with 684 kg of crude protein ha^-1) and then 4–3 t of grain ha^-1. In this instance, neither the grain yield nor the number of spikes per plant were reduced after clipping, in spite of the fact that the shoot apices were removed.
Plant height and lodging were reduced by a forage cut. In triticale, the number of days to heading was increased even more when the cut was late, but no effect was observed in barley.     

Contribution of main stem and tillers to durum wheat (Triticum turgidum L. var. durum) grain yield and its components grown in Mediterranean environments

Under terminal drought conditions, cereal varieties with limited tillering have been suggested to be advantageous, because they have fewer nonproductive tillers, thereby limiting water consumption prior to anthesis. In this study, four field trials were conducted over two growing seasons in southern Spain, under rainfed and irrigated conditions. Twenty-five genotypes were studied to evaluate the contribution of the main stem (MS) and tillers to grain yield and its components. Significant differences were found among genotypes for these contributions under non-stressed environments, but these differences were not significant under water-stress conditions. The contribution of the MS to plant grain yield was higher than that of tillers (68% vs. 32%) and was stable between years in irrigated trials. However, in the rainfed trials, MS contributed differently depending on year-to-year climate variations. Thus, under favorable weather conditions the contribution of MS to grain yield was higher than in the unfavorable year (85% vs. 59%). In irrigated environments, MS and tiller grain yield depended on the number of grains per spike, spikelets per spike, and thousand kernel weight (TKW). Under water-limited conditions, MS yield depended on the number of grains per spike and grains per spikelet, whereas the number of spikelets and TKW had less influence on MS grain yield. Furthermore, under water-stress conditions, high tillering genotypes showed yield levels similar to the genotypes with restricted tillering. Additionally, there was no significant evidence of a positive or negative effect of maximum tiller number on grain yield under rainfed conditions.     

The effect of height and frequency of mowing on the yield and composition of perennial ryegrass—white clover swards in the autumn to spring period

Ninety-six plots (3 × 2 m) of well-established perennial rye grass/white clover pasture were mown to heights of 2·7 (Low) or 3·96 (High) cm (rising plate meter) at 14-, 28-, 84- or 112-d intervals in autumn-winter. A 7-, 14- and 28-d mowing interval was superimposed in spring on each autumn–winter mowing interval treatment with the low and high mowing heights altered to 2·92 and 4·80 cm, respectively.
With the low cutting height, accumulated herbage DM was more than doubled (1806 ± 79 kg DM ha^-1) compared to a 'high' (754 ± 49 kg DM ha^-1) cutting height in autumn–winter and this was due to increased harvesting efficiency rather than growth as estimated by leaf extension. Although defoliation interval had no effect on DM yield, the grass component increased and clover decreased. The composition effect carried over into spring. On average, 3·5 tillers were produced over winter for each ryegrass tiller present in autumn and tiller densities were higher in spring. Tillers produced over autumn–winter contributed more than 60% of ryegrass growth by early spring.
In early spring (16–30 September), the low cutting height increased herbage DM yield, in mid-spring (1–14 October) it reduced DM yields particularly in combination with short defoliation intervals, while in late spring (14 October to 11 November) cutting height had no effect on DM yields.
Over the entire spring period there was a very marked effect of defoliation interval on DM yields.     

不同小麦品种植株光合器官受损对单穗籽粒产量的影响及其补偿效应

为了比较不同小麦品种植株绿色器官的光合功能受损对穗粒重的影响及其补偿效应,用剪叶、包穗、包穗下节的方法对8个冬小麦品种在8种处理下的单穗籽粒产量进行了研究。结果表明,小麦扬花后,各部分绿色器官的光合功能受损对单穗籽粒产量的影响在品种间存在一定差异。包穗使各品种穗粒重损失22.33%～53.11%,多数品种间差异显著;包穗下节及同时剪上三叶片,各品种穗粒重损失4.44%～25.87%和10.08%～30.59%,品种间也有一定的差异;剪旗叶各品种穗粒重损失5.23%～14.42%,品种间差异多不显著;各处理对粒重和穗粒数均有影响。在此条件下,不同品种其植株各部分光合器官对穗粒重的影响各有特点,并且植株个体对穗粒重、粒重的损失能产生一定的补偿效应。不同品种产生补偿效应的能力有一定差异,同一品种在不同处理条件下的补偿效应也不相同。参试各品种中,小偃6号在所有处理条件下的穗粒重损失率都较小,补偿效应明显。     

四川小麦分蘖冗余及理想群体构成研究

为探究四川小麦分蘖冗余及理想群体构成,以5个典型冬小麦品种为材料,在分蘖始期至拔节期每2d剪一次分蘖,设置3个处理[仅保留主茎,剪除所有分蘖(B0);保留主茎和1个大分蘖(B1);保留主茎和2个大分蘖(B2);不剪分蘖(CK)],对成熟期小麦株高、穗部性状和单株产量进行调查分析。结果表明,5个品种间各性状对剪除分蘖的反应表现较一致。单株穗数以B0处理最低(1.00穗),B1、B2和CK处理单株穗数在同一水平(1.96~1.98穗);B0处理下穗粒数(49.5粒)、千粒重(53.2g)、穗长(11.3cm)、有效小穗数(17.7个)较CK显著增加,但株高(86.5cm)和单株产量(2.54g)均最低;B2处理的单株产量(4.27g)介于B1(4.39g)和CK(4.13g)之间,但与二者差异均不显著;B1处理下株高(88.1cm)适中,主茎和分蘖的穗长(11.0、10.6cm)增加,有效小穗数(17.8、16.4个)增多,最终主茎和分蘖的穗粒数(47.4、39.5粒)显著高于B2(44.2、34.7粒)和CK(43.8、36.0粒),主茎和分蘖的千粒重(50.7、52.5g)略高于B2(50.3、50.9g)和CK(49.6、51.3g),穗数、穗粒数、千粒重协调,单株产量(4.39g)最高。因此认为,保留主茎1个分蘖处理消除了冗余分蘖对资源的浪费,减少了内耗,是四川小麦优质、低耗、高产的最佳茎蘖组合。     

春小麦品种农艺性状的主成分分析与聚类分析

为给春小麦育种中品种资源的合理利用提供依据,选取国内外43个春小麦品种为试验材料,根据株高、主茎穗长、主茎穗小穗数、单株有效穗数、主茎穗粒数、抽穗期、散粉期、成熟期、单株粒数、单株粒重和千粒重11个农艺性状进行主成分及聚类分析。结果表明,通过主成分分析将11个农艺性状简化为彼此互不相关的5个主成分,即籽粒产量因子、成熟因子、有效穗数因子、穗长因子和千粒重因子,提供的信息量占全部信息量的90.05%。利用这5个主成分因子进行系统聚类,将43个春小麦品种划分为7大类群,其中第4类群的品种综合产量性状好。分类结果与品种系谱基本一致。     

水旱生态型冬小麦品种杂种优势分析

为了了解冬小麦水旱生态型杂种优势表现,在雨养条件下,选用水旱两种生态型的小麦品种各4个,组成4×4不完全双列杂交,分析了F_1代株高(X_1)、穗下茎长(X_2)、单株穗数(X_3)、穗粒数(X_4)、千粒重(X_5)、单株生物产量(X_6)、单穗重(X_7)、单株粒重(Y)等8个主要农艺性状的杂种优势及各性状优势间的相关性,并进行了通径分析。结果表明,F_1杂种优势普遍存在。单株粒重的平均优势最高,其次是单株生物产量。产量三要素平均优势以千粒重优势最高,单株穗数次之,穗粒数优势最低。各性状不同组合的杂种优势间存在较大变异。各个性状优势对产量优势的贡献排序为X_3>X_4>X_5>X_6>X_7>X_2>X_1。其中,单株穗数对产量优势的直接效应最高,穗下茎长和单株生物产量对籽粒产量主要起间接作用,与单株粒重优势相关达显著和极显著水平。试验表明,旱地小麦高产育种应注意选育分蘖力强,成穗率高,穗下颈较长,具有一定株高和生物产量的品种,在保持一定穗数的基础上,协调好千粒重与穗粒数及其它农艺性状的关系。     

耕种方式对华北地区冬小麦群体质量及产量的影响

为探讨华北地区耕种方式对冬小麦群体质量和产量的影响,2011-2013年通过大田定位试验,分析了免耕条播、深松条播、旋耕条播、机械撒播方式下冬小麦生育进程、群体大小、干物质积累、产量及其构成的特点。结果表明,免耕条播冬小麦分蘖不足,群体数量小,干物质积累少,叶面积指数偏低,穗粒数、千粒重较低,产量低于其他耕种方式;深松条播冬小麦成熟略晚,群体较大,茎蘖成穗率高,干物质积累量、叶面积指数、成穗数和产量均高于旋耕条播,穗粒数、千粒重与之差异不明显;机械撒播冬小麦虽然存在种子有效覆盖度小、种子深浅不一、出苗率低等缺点,但分蘖优势明显,干物质积累最多,叶面积指数最大且最大值出现早,千粒重、穗粒数略有降低,成穗数极显著高于其他处理,较旋耕条播和深松条播分别增产15%和11%以上。综合来看,机械撒播有利于优化小麦群体质量,提高整体产量水平,是目前华北地区冬小麦较理想的耕种方式。     

Effect of winter grazing date on yield components of Lolium perenne (L.)/Trifolium repens (L.) hill pasture

Perennial ryegrass/white clover pastures were grazed at different times in the winter to study the effect of time of grazing on subsequent plant growth. In 1983–84, 1984–85, and 1985–86, pastures were grazed to a residual of 400 kg dry matter ha^-1 by sheep once in early December (D), January (J), February (F), March (M), or April (A) and compared with an ungrazed control (C). Rates of herbage accumulation on C in the winter were low, averaging 6, -9, and 2 kg dry matter ha^-1 in December, January, and February, respectively. Little forage production occurred during the month immediately following winter grazing. Herbage accumulation rate then increased sufficiently to replace the forage removed from winter-grazed paddocks by early spring. By May, herbage mass on grazed treatments was similar to C except for D and A which averaged 20 and 47% less forage than C, respectively (P<0·01). Herbage accumulation rates of D were unique among winter grazing treatments in never exceeding those of C. By May 1986, D yielded less perennial ryegrass compared with C (P<0·05). Grazing reduced the number of leaves per ryegrass tiller for 1 to 2 months following grazing. By May, J, F and M had numerically more tillers m^-2 and more leaves per tiller than C. Similar May yields of J, F, M, and C resulted from fewer but larger and slightly less leafy tillers of ungrazed compared with winter grazed plants.     

施氮量和比例对冬小麦产量和蛋白质组分的影响

为了给小麦优质高产栽培提供依据,以强筋小麦品种济麦20为试验材料,采用二因素随机区组试验设计,研究了氮肥运筹对小麦植株性状、产量和蛋白质组分的影响.结果表明.株高、穗长、穗粒数均与产量呈正相关,其中穗长与产量相关显著(r=0.607*),在不同施氮量和底追比例处理问,株高、德长、千粒重、容重和产量均有显著差异.在施氮量150~300 kg/ha范围内,穗长、穗粒数和产量有随施氮量增加而提高的趋势,其中产量在处理间差异显著,以施氮300 kg/ha的处理产量最高.氮肥底施和追施的比例对籽粒产量有显著影响,在本试验中以底追比例5:5的处理产量最高.不同蛋白质组分对施氮的反应有差异,醇溶蛋白、谷蛋白和总蛋白含量均随施氯量的增加而逐渐提高.醇溶蛋白和总蛋白含量随追氯比例的增加而逐步提高.籽粒产量和蛋白质含量时底追比例的反应有一定差异.     

返青期断根对秸秆覆盖冬小麦产量及叶片光合特性的影响

为了解返青期断根对黄土高原旱地保护性耕作下小麦产量形成及水分利用的调控作用,在陕西长武县开展旱地秸秆覆盖条件下冬小麦返青期断根试验,分析了返青期断根对冬小麦籽粒产量、地上部生物量、收获指数、产量构成三要素、拔节期群体数量、生育期耗水量、水分利用效率、花后旗叶光合特性及衰老特性的影响。结果表明,返青期断根对冬小麦地上部生物量、穗数、粒重和生育期耗水量没有显著影响。与CK(不断根)相比,返青期断根后冬小麦拔节期总茎数减少了11.9%,开花期叶面积指数、花后旗叶叶绿素含量、光合速率和蒸腾速率提高,分蘖成穗率、穗粒数、籽粒产量、收获指数和水分利用效率分别增加了14.1%、10.5%、8.2%、10.4%、17.5%和20.4%。这说明返青期断根可促进秸秆覆盖条件下冬小麦分蘖成穗,增加花后旗叶光合作用,改善穗部结实特性,提高籽粒产量和水分高效利用。     

施肥和群体密度对春小麦产量与品质形成的调控效应

为给春小麦养分科学管理提供参考,采用大田小区试验,以春小麦品种龙麦26和克旱16为材料,研究了肥料施用量对小麦不同密度群体籽粒产量与品质形成的调控效应。结果表明,施肥与群体密度对春小麦产量具有明显的互作效应。低施肥水平下,春小麦产量随群体密度的增加而增加;中高施肥水平下,产量随群体密度增加出现波动,但均高于低施肥水平的产量。群体密度的增加降低了收获穗数饱和度、穗粒数及籽粒面筋含量,但增加了籽粒容重;施肥量的增加提高了穗粒数、千粒重和面筋含量;群体密度和施肥量对小麦加工品质的影响较为复杂,且对不同基因型品种的调控效应不同。     

小麦显性矮源对株粒重及产量构成因素的影响

利用8个普通小麦品种与5个不同显性矮源进行回交产生的8套近等基因系，进行了株粒重及产量构成因素的研究，结果表明，显性矮源对有效穗数没有显著影响，对株粒重、穗粒数和千粒重都有显著的降低作用，降幅最小的是具有奥尔森矮源的近等基因系，分别降低19．6％、26．9％和10．5％；降幅最大的是具有矮变1号矮源的近等基因系，分别降低68．9％、66．7％和24．7％。携带Rht10基因的西农02和矮变1号矮源转育的近等基因系之间的株粒重、穗粒数和千粒重的差异都显著或极显著，说明它们对普通小麦品种的影响不一致。具有显性矮源的近等基因系株粒重偏低的主要原因是穗粒数减少和千粒重降低。具有显性矮源近等基因系的株粒重与株高的回归分析表明，适当提高显性矮源的株高可以提高株粒重。     

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.     

云南省不同环境对二棱大麦产量及产量构成因素的影响

对2004至2007年云南省22品种次的二棱大麦在云南省(高、中、低)3个不同海拔环境下进行产量构成因素变化及其与产量的相关分析和通径分析。结果表明产量、有效穗、千粒重和生育期在不同环境下差异达到极显著水平,穗粒数和株高差异不显著;平均产量在低海拔环境最高,高海拔环境下最低;在低海拔环境下,有效穗和千粒重都显著高于其它两个环境,生育期在高海拔环境下最长,平均比低海拔环境下长2d。相关分析表明在高海拔环境下产量构成三因素与产量的相关性大小为有效穗>千粒重>穗粒数,且穗粒数与产量负相关;在中海拔环境下穗粒数>有效穗>千粒重;低海拔环境下则为千粒重>有效穗>穗粒数。通径分析表明在中海拔环境下穗粒数对产量的直接效应最大,其余环境都是千粒重的直接效应最大;而在高海拔环境下穗粒数对产量的直接效应为负值。     

超高产冬小麦四种微量元素的积累及其与产量性状的关系

为了明确超高产冬小麦锰、锌、铜、硼的吸收积累特点及与产量相关性状的关系,于2005-2006年冬小麦成熟期测定了不同小麦品种产量相关性状及植株和籽粒中锰、锌、铜、硼的含量与积累量。结果表明,成熟期不同冬小麦品种植株和籽粒中4种元素的含量和积累量存在不同程度的差异,但都表现为锰>锌>铜>硼。植株锰积累量与穗粒数呈显著正相关,植株锰含量和积累量与单株成穗数呈显著负相关。植株和籽粒锌含量和积累量与每穗小穗数、结实小穗数和穗粒数呈正相关,与不孕小穗数呈负相关,但相关均未达到显著水平。植株铜含量与每穗小穂数、结实小穗数、穗粒数和产量均为正相关,且相关达到显著或极显著水平。植株铜积累量与总小穗数、结实小穗数呈显著正相关,与不孕小穗数呈显著负相关。植株硼积累量与产量达到显著正相关水平。综合分析可知,4种微量元素在增加产量和优化产量构成因素中起着不同的作用,在小麦生产中应针对具体的限制因素确定不同微量元素肥料的施用技术。     

Winter cereals grown for grain and for the dual purpose of forage plus grain I. Production

In many rainfed regions of Euro-Mediterranean countries, current political and socio-economic developments demand research in alternative production systems to the common cereal grain monoculture. We studied the option of producing forage in winter by growing cereals for dual purpose (forage plus grain) in a Mediterranean environment. The effect of clipping on forage and grain production was assessed between 1987 and 1990 at Granada, southern Spain, in four cereal cultivars, and in one barley cultivar under three sowing systems.Winter forage yield of cereals, all clipped once at the stage of lemma primordia, was highly variable (25 to 311 g m⁻² of herbage dry matter), with considerable differences among cultivars, sowing systems and seasons. Treatments that had higher forage production were those of either longer crop duration before clipping date (with higher leaf numbers on the main stem and tiller numbers per plant) or higher plant density. Forage production was not related to grain yield reductions due to winter clipping.Averaged over cultivars, sowing systems and seasons, clipping reduced grain yield by 1%, but yielded some 127 g m⁻² of dry matter per season in a period of pasture shortage. Nevertheless, the responses to winter clipping differed among seasons. In 1987/88, clipped cereals produced more dry matter and grain than the control. In contrast, in the last two seasons, clipping reduced dry matter and grain production. Early sowing modified the response to clipping in these last two seasons. Grain yield of early sown barley was not reduced by clipping in 1988/89 and was even increased in 1989/90.The dual-purpose target for cereals could be an alternative to traditional grain monoculture in some Mediterranean environments, provided that adaptations of the traditional crop management to dual purpose, such as the optimization of sowing date and cultivar, are undertaken.     

种植密度对不同穗型冬小麦品种结实特性和产量的影响

为了明确种植密度对冬小麦结实特性和产量的影响，于2020-2021年以大穗型品种衡观35和多穗型品种济麦22为试验材料，设置4个种植密度水平，分别为每公顷基本苗180万（D180）、300万（D300）、420万（D420）和540万（D540）株，比较分析了不同种植密度下冬小麦小花结实、籽粒空间分布特征和产量的差异。结果表明，随着种植密度的降低，衡观35主茎穗上部和I分蘖穗下部、济麦22主茎和I分蘖穗中上部小穗位的结实粒数呈增加的趋势。降低种植密度促进了两个品种穗中部小穗位弱势小花、上部和下部小穗位强势小花的结实。衡观35主茎穗中上部和I分蘖穗中部小穗位的结实粒数均高于济麦22。开花期穗干重与可孕小花数呈显著正相关。低种植密度处理下开花期穗干重的增加为其获得较高的穗粒数奠定了良好的物质基础。种植密度对千粒重影响不显著，但显著降低了衡观35的穗数。由于产量构成三要素的协调作用，两个品种均在D300处理下获得了最高产量，但与其余种植密度处理间差异均不显著。综合来看，在保证穗数的前提下，适当降低种植密度会促进冬小麦主茎和分蘖穗结实，进而增加穗粒数和产量，可节约生产成本，有利于冬小麦绿色高产高效生产。