Effects of variation in temperature and light intensity at different times on growth and yield of spring wheat

Spring wheat grown in pots outdoors was transferred to growth rooms for various periods to study the effect of increasing the temperature from 14-4 to 20-3 ^oC (Expt 1) or from day/night values of 15-0/15-2 to 20-0/15-2 ^oC (Expt 2) and of increasing the amount of visible radiation in a 16 h day from 424 to 792 J cm^-2 (Expt 1) or 374 to 740 J cm^-2 (Expt 2). There were no interactions between temperature and radiation. In Expt 1 neither the increase in temperature nor extra radiation, applied for 14 days immediately after the appearance of double ridges on the stem apex, or 14 days later, increased grain yield at maturity. Warmth early, but not late, increased dry weight, leaf area and the number of floret primordia immediately after treatment, but these effects had disappeared by anthesis, 30 days later. Dry weight but not leaf area was increased by extra radiation but the effects had disappeared 2 wk after treatment. An increase in temperature imposed for 16 days starting 5 or 21 days after anthesis (Expt 2) increased dry weight of the ear and decreased that of the rest of the plant immediately after treatment, and decreased leaf area at all times. When plants from the two temperatures were put together in the same conditions, ear growth of plants that had been in the warm was slower than that of plants from the cold treatment, so that the difference in ear weight observed after 16 days of treatment reversed and grain yield was decreased by warmth applied in either period; the component of yield decreased by warmth was grain size. Additional radiation in either post-anthesis period increased dry weight of all parts of the plant and had negligible effects on leaf area. Final grain yield was increased by c. 15% because the individual grains were larger. Early treatment also increased grain number slightly. The effects of treatment during the two post-anthesis periods were similar in size, and additive.     

播期对春小麦生长发育及产量的影响

为了给陇中半干旱区春小麦高产栽培提供依据,2010年在甘肃定西进行了春小麦分期播种试验,并对不同播期条件下春小麦生长发育及产量形成进行了分析。结果表明:随着播期的推迟,春小麦播种-抽穗期日数减少、全生育期明显缩短;5月下旬之前,越早播种的春小麦LAI越大,5月下旬之后,播种愈晚春小麦LAI越大。早播春小麦LAI峰值靠前,晚播峰值滞后;6月下旬之前,播期早的春小麦叶绿素含量高于播期晚的,6月下旬之后播期愈早叶绿素含量下降愈快;不同播期春小麦群体生长率和净同化率在孕穗-抽穗期后差异显著,表现为3月18日播期最大,4月7日播期最小。各播期干物质累积在拔节期后表现为快速递增趋势。在拔节期前,早播处理的干物质积累速率较慢。随着播期的推迟,单株干物质最大积累速率出现时间提前,籽粒最大灌浆速率出现时间推迟,千粒重表现为先升后降;灌浆3个阶段各参数受播期影响比较显著;早播春小麦产量最高。     

田间增温对半干旱区春小麦生长发育和产量的影响

在中国气象局兰州干旱气象研究所定西气象和生态环境试验站,利用开放式红外增温系统设置增加0 ℃(对照)、1 ℃、2 ℃3个温度梯度,模拟田间增温对春小麦生长发育、产量及产量构成因素的影响.结果表明: 冠层温度增加1～2 ℃,春小麦的全生育期比对照缩短7～11 d.生育前期增温使株高增高,叶面积指数增大;从拔节期开始增温使株高和叶面积指数降低,且增温2 ℃处理的效应大于增温1 ℃处理.温度升高导致叶绿素含量降低,尤其是灌浆后期到乳熟期.增温1～2 ℃,产量较对照降低25.4%～45.5%,主要是由于穗粒数和穗粒质量显著减少.增温处理明显降低了春小麦田间土壤贮水量,0～100 cm土壤贮水消耗量随温度的增加呈逐渐增加趋势,而在100 cm以下深层土壤变化趋势不明显.     

Effects of soil fumigation on disease incidence, growth, and yield of spring wheat

Plots were fumigated with various amounts of D-D or 85% dazomet dust and sown with spring wheat given various amounts of nitrogenous fertilizer. Dazomet increased yield and decreased take-all disease in the first crop after application, but increased the disease in the second crop. Although D-D increased take-all slightly, it increased yield in 1966, but in 1967 it decreased yield and its use was associated with a severe ear deformity. Fumigation had little effect on eyespot, sharp eyespot, root browning (Fusarium spp.), or browning root rot (Pythium spp.), but decreased nematode damage where nematodes were numerous.     

地膜覆盖对土壤水温和春小麦产量形成的影响

通过大田试验研究了地膜覆盖对土壤水温状况及春小麦产量形成的影响．结果表明,地膜覆盖对土壤的增温作用在春小麦生育期内呈“U”型变化,地膜覆盖可以通过防止蒸发和提升土壤深层水分至作物可利用层来增加土壤中有效水含量,利于作物利用．地膜覆盖的增温保墒作用利于作物前期生长和水分利用,在生育后期覆膜,作物根系发育受到抑制,作物蒸散量和水分利用效率下降,影响产量的形成．对照(CK)、播前灌水(W)、全程覆膜(M)、播前灌水 覆膜30d(WM30)、播前灌水 覆膜60d（WM60)及播前灌水十全程覆膜(WMw)6个处理的产量分别为2554、2424、2750、3138、3305、3123kg·hm^-2,最佳覆膜时间在40—60d．     

Effects of elevated carbon dioxide, ozone and water availability on spring wheat growth and yield

Spring wheat (Triticum aestivum L. cv. Dragon) was exposed to elevated carbon dioxide (CO₂), alone (1995) or in combination with two levels of increased ozone (O₃) (1994) or increased irrigation (1996) during three successive growing seasons as part of the EU ESPACE‐wheat programme and conducted in open‐top chambers (OTCs) and ambient air (AA) plots at Östad, 50 km north‐east of Göteborg, Sweden. Doubling the CO₂ concentration had a positive effect on grain yield in all 3 years (+21, +7 and +11%, respectively), although only statistically significant in 1994. That year was characterised by a warm and dry summer in comparison with 1995 and 1996, in which the summers were more humid and typical for south‐west Sweden. In 1994, the CO₂‐induced increase in grain yield was associated with an increase in the duration of the green leaf area, a positive effect on straw yield and on the number of ears per square metre and a negative effect (?13%) on grain protein concentration. Harvest index was unaffected by the elevated CO₂ concentration. The only statistically significant effect of elevated CO₂ in 1995 was a decrease in the grain protein concentration (?11% in both CO₂ concentrations), and in 1996 an increase (+21%) in the straw yield. In 1996 the soil water potential was less negative in elevated CO₂, which is likely to reflect a lower water consumption of these plants. Addition of extra O₃ significantly affected the grain yield (?6 and ?10%, respectively) and the 1 000‐grain weight negatively (?3 and ?6%). Statistically significant interactions between CO₂ and O₃ were obtained for the number of ears per unit area and for the 1 000‐grain weight. The 1 000‐grain weight was negatively affected by O₃ in low CO₂, but remained unaffected in the high CO₂ treatment. There was a significant decrease (?6%) in the grain protein concentration induced by elevated irrigation. The chambers, compared with AA plots, had a positive effect on plant development and on grain yield in all 3 years.     

气候变暖对高寒阴湿地区春小麦生长发育和产量的影响

利用甘肃省岷县农业气象观测站1987—2004年的观测资料,探讨了气候变暖对高寒阴湿雨养农业区春小麦生长发育和产量的影响。结果表明：近18年来该地区气候变化呈明显的暖干化趋势,并且变暖的幅度和速率远远大于全国近50年的平均值,春小麦对气候变暖的响应表现在生长期缩短、产量增加;春小麦整个生长过程中,温度升高对各发育阶段的影响不完全一致,各阶段变暖对产量及产量构成要素的影响也存在差异,开花-乳熟期的温度增加和产量的相关性最大,达到极显著水平（P＜0.01）;出苗-拔节期、开花-成熟期的温度增加以及拔节-孕穗期的温度降低,是引起每穗籽粒数增加而不孕小穗率减少,最终导致产量增加的直接原因;春小麦生长期间日平均气温每升高1 ℃,生长期缩短约9.2 d,产量增加约26.2%;预计随着未来气候进一步变暖该地区的春小麦生长发育和产量将会继续受到影响。     

Effect of variation in ear temperature on gibberellin content of wheat ears

When the ears of wheat were grown after anthesis at temperatures different from the rest of the plant the gibberellin content of the ears increased more rapidly at higher ear temperatures, whilst the plant temperature had little effect. This greater rate of gibberellin accumulation was associated with a greater rate of ear dry weight increase. Wheat ears detached from the plant increased their gibberellin content over 4 days when provided with sucrose and ewfkaurene.     

底墒与磷肥互作对春小麦产量形成的影响

研究了浇底墒水和施磷肥对春小麦产量形成的影响.实验设4个处理对照(CK);耕作层施磷(P);浇30 nm底墒水(W);施磷加浇30mm底墒水(PW).测定土壤含水量、根系生物量、地上生物量和测产等.结果表明,WP处理根重和中下层分配比例均较高.与W处理相比,WP处理利用底墒并没有增加,但水分利用效率和产量均增加.决定产量的主要因素是小麦早期小穗和小花形成的数量和质量.W和WP两个浇底墒水的处理,其土壤水分利用量平均为34.6 mm,略高于所浇的底墒水的量(30 mm).CK、P、W、WP等4个处理的籽粒产量分别为91 7.7,1191.1,2516.5,2734.1 kg/hrm2,水分利用效率分别为0.186,0.192,0.172,0.207 g/(mm.m2).     

苗期刈割伤害对春小麦生长及产量的影响

通过1996年大田试验研究了黄土高原半干旱区春小麦苗期（三叶－心期）受到不同强度刈割伤害（模拟动物的采食）后的补偿作用,结果,在大田试验条件下,受轻度刈割（刈割一半叶面积,H0,H1）,春小麦的补偿效应大于受重度刈割（刈割全部叶面积T0,T1）春小麦的补偿效应,且都低于未受刈割处理（对照,CK0,CK1）,即CK0＞H0＞T0;CK1＞H1＞T1,刈割处理后,灌溉一次水（CK1,H1,T1）虽可增强其补偿能力,促进小麦的生长,但仍为低补偿。     

Effects of net blotch on growth and yield of spring barley

The effect of net blotch on the growth and yield of cv. Beatrice spring barley was examined in a greenhouse experiment. Separate inoculations at growth stages 21 and 34 reduced green leaf area, root weight, leaf sheath and stem weight and tiller number. The early inoculated plants, which responded and recovered more rapidly than later treated ones, suffered a loss in grain yield and this was related to the amount of disease, the loss in green leaf area and the reduction in unit leaf rate.     

Effects of inoculation with Septoria nodorum on yield components of spring wheat

Spring wheat, cv. Kolibri, was artificially inoculated with spore suspensions of Septoria nodorum, from the time of full expansion of the third leaf to the end of flowering and the effect on yield components recorded. Most components were reduced by increasing severity of infection and grain weight losses of 56 and 35% were produced on single-stemmed and tillering plants respectively, by the most severe infection. The effects on components of yield differed considerably between the main stems and the tillers and an increase in grain number on moderately infected tillers partly compensated for reductions in yield on the main stem.     

西北干旱区不同海拔高度地区气温变化对春小麦生长的影响

基于1981—2006年西北干旱区高海拔地（民乐站）和低海拔地（张掖站）农业气象观测站的观测资料,对民乐站和张掖站的气温变化及其对春小麦生长发育和产量的影响进行了研究.结果表明：研究期间,民乐站、张掖站的气温均呈增加趋势,且高海拔地区的增温幅度大于低海拔地区;民乐站春小麦对气温变暖的响〖JP2〗应表现为生育期缩短、产量增加,张掖站春小麦对气温变暖的响应表现为生育期缩短、产量下降;春小麦生育期内日均气温每升高1 ℃,民乐站和张掖站春小麦生育期分别缩短8.3 d和3.8 d.民乐站春小麦生育期内最高气温低于30.4 ℃时,春小麦生育期和产量均小幅增加,当超过30.4 ℃时,春小麦生育期缩短、产量下降.     

增温对宁夏北部春小麦叶片光合作用的影响

为探索宁夏北部春小麦叶片光合作用应对未来气候变化的响应机制,进一步阐明气候变暖对干旱半干旱区春小麦生长的影响。采用自动控制红外线辐射器野外增温模拟气候变化的方法,以不做增温处理的春小麦冠层温度为基础温度,设置不同增温梯度(CK:0℃、T1:0.5℃、T2:1℃、T3:1.5℃、T4:2.0℃),开展气温升高对宁夏北部春小麦全生育期叶片叶面积、光合色素含量、光合特性、叶绿素荧光参数、干物重、产量等指标的影响试验。结果表明:春小麦苗期—拔节期,温度增加0.5℃时叶片叶面积、叶绿素含量、Pn(净光合速率)、WUE(叶片水分利用效率)呈上升的趋势。温度增加1.0—2.0℃时以上指标呈下降趋势,同时Ls(气孔限制值)呈上升趋势,Ci(胞间CO2浓度)呈下降的趋势,说明此时叶片Pn的下降主要是叶绿素含量的下降和气孔限制导致的。春小麦拔节期之后,叶片叶面积、叶绿素含量、Pn、WUE、Ls随温度的增加呈下降的趋势,而Ci随温度的增加呈上升的趋势,说明此时叶片Pn的下降则主要是叶绿素含量的下降和非气孔因素导致。叶绿素荧光参数表明在苗期—拔节期,春小麦对温度升高具有一定的抗逆性,能应对增温胁迫以热耗散的形式做出自我保护。拔节期以后,春小麦叶片光系统Ⅱ反应中心受温度胁迫可逆性失活,光合机构受到破坏。另外,春小麦干物重的变化趋势与叶面积等指标的变化趋势基本一致,产量及产量构成因素小穗数、穗粒数、千粒重随温度的增加显著降低,说明春小麦拔节期之前增温0.5℃有利于提高叶片光系统Ⅱ的潜在活性,增加叶片抗逆性,促进光合作用的进行,最终使光合产物累积量增多。增温梯度过大或增温时间过长则会使春小麦受高温胁迫,导致叶片光系统Ⅱ原初光能捕获、电子传递等效率降低,光合机构受到破坏,致使叶片Pn、WUE等数值下降,光合产物累积量减少,产量减少。     

Effects of elevated carbon dioxide and ozone on the growth and yield of spring wheat (Triticum aestivum L.)

Spring wheat cv. Minaret was grown under three carbon dioxide(CO₂) and two ozone (O₃) concentrations from seedling emergenceto maturity in open-top chambers. Under elevated CO₂ concentrations,the green leaf area index of the main shoot was increased, largelydue to an increase in green leaf area duration. Biomass increasedlinearly in response to increasing CO₂ (ambient, 550 and 680ppm). At anthesis, stem and ear dry weights and plant heightwere increased by up to 174%, 5% and 9 cm, respectively, andbiomass at maturity was 23% greater in the 680 ppm treatmentas compared to the ambient control. Grain numbers per spikeletand per ear were increased by 0.2 and 5 grains, respectively,and this, coupled with a higher number of ears bearing tillers,increased grain yield by up to 33%. Exposure to a 7 h daily mean O₃ concentration of 60 ppb inducedpremature leaf senescence during early vegetative growth (leaves1–7) under ambient CO₂ concentrations. Damage to the mainshoot and possible seedling mortality during the first 3 weeksof exposure altered canopy structure and increased the proportionof tillers 1 and 2 which survived to produce ears at maturitywas increased; as a result, grain yield was not significantlyaffected. In contrast to the older leaves, the flag leaf (leaf8) sustained no visible O₃ damage, and mean grain yield perear was not affected. Interactions between elevated CO₂ andO₃ influenced the severity of visible leaf damage (leaves 1–7),with elevated CO₂ apparently protecting against O₃-induced prematuresenescence during early vegetative growth. The data suggestthat the flag leaf of Minaret, a major source of assimilateduring grain fill, may be relatively insensitive to O₃ exposure.Possible mechanisms involved in damage and/or recovery are discussed. Key words: Carbon dioxide, ozone, spring wheat (cv. Minaret), leaf damage, tiller, yield     

地膜覆盖和底墒灌溉对春小麦产量形成的影响

大田试验研究了地膜覆盖和底墒灌溉对春小麦产量形成的影响.地膜覆盖利于作物前期生长和水分利用,但不利于后期干物质积累和产量的形成.底墒灌溉对春小麦干物质积累和水分利用均有不利影响.对照 CK 、覆膜 M 、底墒灌溉 W 和覆膜+底墒灌溉 MW 4个处理产量分别为2554.0、2750.1、2424.3、3123.1kg·hm-2,补灌底墒与地膜覆盖具有协同促进作用.     

Effects of aerial pollutants on the growth and yield of spring barley

Open-topped chambers were used to determine the effect of field concentrations of aerial pollutants on the growth and yield of spring barley. Experiments were conducted in the Marston Valley, Bedfordshire, where sulphur dioxide and fluoride are the major pollutants. The charcoal filtered chambers enabled pollutant concentrations to be reduced by 60–70%. Cleaning the air increased straw and grain yields. The filtration was non-selective and did not identify the injurious agent. The chambers were found to accelerate the crop's development by 7–8 days and reduce yield by suppressing tillering.     

多效抗旱驱鼠剂对田间小麦促长增产效果研究

通过多效抗旱驱鼠剂浸种与拌种的田间试验,对小麦12个生长和产量构成因素进行了测定与多元统计分析。结果表明,RPA浓度是决定促长与增产效果的关键。药剂A的700倍水溶液浸种或30-50倍液拌种对苗期促长作用最好;与对照相比,除B的700倍水溶液浸种处理小麦种子,小麦产量比对照降低2.79%,其它处理均有增产作用,增产率为4.79%-98.67%。其中以药剂A的70倍水溶液拌种和C的600倍液浸种,增产效果最为显著,增产幅度达98.49%-98.67%;对11个影响产量因子的通径分析表明,单位面积的有效穗数是决定产量增长率的首要因素。     

半干旱黄土高原地区地膜覆盖和底墒对春小麦生长及产量的影响

在年均降水量为415mm的半干旱地区黄绵土旱地上,以春小麦为供试作物进行大田实验,研究不同底墒(包括低底墒、中底墒和高底墒)下．地膜覆盖(包括不覆膜、播种后覆膜30d、覆膜60d和覆膜120d即全程覆膜)进程对作物生产的影响。结果表明．增加底墒和合理的覆膜进程均会显著增加作物的生长和产量,但底墒不同,其最佳覆膜进程不同：在低底墒时,覆膜处理反而使产量低于不覆膜处理;在中底墒时．覆膜30d产量最高,随着覆膜时间延长．产量呈下降趋势,甚至全程覆膜产量低于不覆膜处理;高底墒以覆膜60d产量最高。综合作物生长和产量,全程覆膜并没有多少实际意义。在同种覆膜处理下,随着底墒的增加,根生物量、地上干物质、叶面积及产量也增加显著,高底墒覆膜60d处理的产量在所有处理中为最高。