Effects of weed harrowing and undersown clover on weed growth and spring cereal yield

Weed competition and nutrient scarcity often restrict organic cereal production, especially where the availability of livestock manure is limited. While harrowing of annual weeds and legume cover crops can be used, these methods are both executed in early spring and may hinder each other. Two cycles of a 2‐year crop rotation were carried out in south‐east Norway (60°42′N, 10°51′E, altitude 250 m) with weed harrowing and undersown cover crops (WHCC) at two fertiliser rates (40 and 100 kg nitrogen ha^?1). The effect of the WHCC treatments was measured by weed density and species, weed biomass, changes in weed seedbank and grain yield. The weed density depended on the interaction between WHCC, fertiliser and year. On average, pre‐emergence weed harrowing reduced weed density by 32% and weed biomass by 49%, while pre‐ and post‐emergence weed harrowing reduced weed density by 59% and weed biomass by 67% compared with the untreated control. Spergula arvensis became more abundant at low rather than at high fertiliser rates. On average, white clover cover crop sown after pre‐emergence weed harrowing resulted in the highest yields for both oat (+12.1%) and wheat (+16.4%) compared with the untreated control. Despite differences in weed population density and biomass among WHCC treatments within years, the weed biomass, weed density and seedbank increased for all WHCC treatments over the 4‐year period. More research is required into improving the efficacy of mechanical and cultural weed suppression methods that organic systems rely on.     

Effect of chemical and cultural methods of weed control on the yield and growth of maize

Abstract

Traditional sorghum cultivars in the tropics are generally photoperiod sensitive, flowering just as or after the rains cease, so that their grains fill and mature during dry weather. Improved cultivars have been developed which flower and mature earlier in the season, when soil moisture levels are generally more favourable for grain filling, which potentially gives higher grain yields. However, the earlier flowering often results in the exposure of developing grain to wet conditions in which it can deteriorate rapidly. Grain moulds are a major component of the sorghum grain deterioration complex, and have become a widespread problem of improved sorghums in temperate and tropical regions. Many fungi have been isolated from mouldy grain, the most commonly occurring genera being Fusarium and Curvularia, and vary from those such as F. moniliforme Sheldon which are pathogenic on young developing inflorescences, to many saprophytic fungi which develop on the mature grains. The review covers terminology, causal agents, time of infection, predisposing factors, effects on yield and quality, control measures, resistance screening procedures and progress and recommendations for further research particularly in resistance.     

Influence of Chromolaena odorata and Mucuna pruriens fallow duration on weed infestation

Summary Fallow management is a major strategy for weed control and soil fertility restoration in tropical farming systems. From 1995 to 1998, weed infestation was evaluated in plots managed under 0, 1, 2 and 3 year fallow durations of (1) a natural bush fallow dominated by Chromolaena odorata ; (2) a planted Mucuna pruriens fallow; and (3) a modified bush fallow without C. odorata . The study was conducted at the Nigerian Institute for Oil Palm Research (NIFOR), Benin City, Nigeria. The 3 × 4 factorial experiment was set up in a split plot arrangement. The three fallow types were the main plots and the four fallow durations were the subplots. Each year, the subplots were planted to maize ( Zea mays , cv. TZSR-W) as appropriate and harvested 14 weeks after planting for yield comparison. Continuous cropping and the modified natural bush fallow increased weed diversity and biomass. Irrespective of fallow type, weed infestation was more gradual in the first year of cropping after fallow than in subsequent cropping years. Regardless of cropping intensity, C. odorata and M. pruriens fallows promoted broad-leaved weeds, chiefly Ageratum conyzoides , Tridax procumbens and Phyllanthus amarus , whereas the modified bush fallow promoted grasses. Maize grain yield was higher in the C. odorata and M. pruriens fallows than in the modified bush fallow, but the yield difference diminished with cropping intensity.     

土壤湿度对三氮苯类除草剂药效的影响及优化方案

以稗草为生物测定材料,运用二次正交旋转组合设计,以土壤湿度和除草剂用量二因子为决策变量,对稗草的抑制率为目标函数,研究土壤湿度对三氮苯类除草剂药效的影响。结果表明,适当的土壤水分是三氮苯类除草剂发挥药效的重要因素,药效随土壤湿度的提高而提高。不同的土壤湿度对不同除草剂药效影响各异,高湿条件下,湿度差异对药效影响大小依次为嗪草酮、西草净、扑草净、莠去津,低湿条件下则相反。除草剂用量与土壤湿度存在最佳发挥药效的组合。     

Chemical composition and phytotoxic activity of the volatile oil of invasive Xanthium italicum Moretti from Xinjiang, China

Aerial parts of Xanthium italicum in an air tight container greatly inhibited root elongation of radish,implying that this invasive plant could release biologically active volatile organic compounds(VOCs)into the environment to affect other plants' growth.This phenomenon was further studied by evaluating the phytotoxic effects of X.italicum essential oil against two dicot plants,amaranth(Amaranthus mangostanus L.)and lettuce(Lectuca sativa L.),and two monocot plants,wheat(Triticum aestivum Linn)and ryegrass(Lolium multiforum),and analyzing the chemical composition of the oil.Among the 4 test species,amaranth was the most sensitive plant,0.5μl/mL essential oil application resulted in a 50% reduction on root elongation,and 2.5 μl/mL essential oil almost completely inhibited its seedling growth.Wheat was the least sensitive species,whose root growth was reduced to 36% of control by 5 μl/mL essential oil.The essential oil exerted moderate inhibitory effect on both lettuce and ryegrass.Compared to a commercial herbicide-Harness,X.italicum oil exhibited stronger phytotoxicity on amaranth,lettuce and wheat,but weaker activity on ryegrass.The chemical composition of the essential oil isolated by hydrodistillation from the aerial parts of X.italicum Moretti was analyzed by GC/MS.Thirty two compounds were identified,representing 94.89% of total oil,which was found to be rich in monoterpene hydrocarbons(60.71%).The main constituents of the oil were limonene(51.61%),germacrene B(6.98%),δ-cadinol(5.94%),β-pinene(5.23%),α-caryophyllene(5.1%)and bornyl acetate(3.15%).Bioassay revealed the dominant constituent-limonene,was unlikely the responsible phytotoxic compound due to its low biological activity;rather,there might be other oil constituent(s)that either act alone,or work together,and possibly assisted by synergistic effect,to display the phytotoxic activity.Our results suggested that X.italicum might produce allelopathic VOCs to facilitate its invasion success.This is the first report on the phytotoxic activity and the chemical composition of the essential oil of X.italicum Moretti from China.     

Effects of density and sowing pattern on weed suppression and grain yield in three varieties of maize under high weed pressure

We tested the hypothesis that improved weed suppression by maize can be achieved through increased crop density and spatial uniformity. Field experiments on three varieties of maize sown at three densities (5, 7 and 10.5 seeds m^?2) and in two spatial patterns (grid pattern and rows) under very high weed pressure from Brachiaria brizantha were performed in 2012 and 2013. We measured weed biomass 1 month after sowing and at harvest, and grain yield at harvest. Density, variety and sowing pattern all had strong and significant effects on both weed biomass and yield. On average, weed biomass was reduced (by 72% in the first year and 58% in the second year), and grain yield was increased (by 48% and 44%) at the highest density in the grid pattern compared with standard sowing practices (medium density, row pattern). There was a significant density × variety interaction, which is evidence for genetic differences in the response of the varieties to density in characteristics that influence weed suppression. The variety that suppressed weeds best at high density had the lowest variation in the angle of insertion of the oldest living leaf at harvest (leaf 6), supporting the hypothesis that reduced phenotypic plasticity may be advantageous for weed suppression under high density and spatial uniformity. Increased density and uniformity can contribute to weed management in maize in many cases, potentially reducing the need for herbicides or mechanical weed control.     

钾肥种类和施钾时期对油葵产量及品质的影响

为分析钾肥种类和施钾时期对油葵产量以及品质的影响,选取油葵杂交品种陇葵杂3号,采用2因素3水平（2个钾肥种类：氯化钾（F1）、硫酸钾(F2);3个施钾时期：全部种前基施（T1）、 50% 基施+50%现蕾期追施（T2）、 25%基施+50%现蕾期追施+25%花期追施（T3））随机区组试验设计,于2014-2016年在甘肃省景泰条山农场进行田间试验。结果表明：KCl和K₂SO₄这两个钾肥品种的盘径、千粒重、粗脂肪含量、产油量、亚麻酸含量间没有明显的差异。与施用K₂SO₄相比,施用KCl的产量在2014年显著增加,F1T2的产量较F2T2增加了4.96%,F1T3较F2T3增加了4.06%。出仁率、油酸含量在2015年和2016年显著增加,F1T1的出仁率较F2T1在2015年和2016年分别增加了1.50%、2.99%,F1T2的出仁率较F2T2在2015年和2016年分别增加了1.76%、19.7%;2015年F1T2的油酸含量较F2T2增加了5.92%;2016年F1T3的油酸含量较F2T3增加了9.09%。粗蛋白含量在2014年和2016年显著降低,F2T3的粗蛋白含量较F1T3在2014年和2016年分别增加了9.95%、8.87%。粗蛋白产量在2016年显著降低,F2T3的粗蛋白产量在2016年较F1T3增加9.29%。亚油酸含量在2015年和2016年显著降低, F1T3的亚油酸含量较F2T3在2015年和2016年分别增加了3.17%和3.03%。施钾时期对油葵的盘径、亚麻酸含量没有显著影响,但对油葵的千粒重、出仁率、产量、蛋白质含量、蛋白质产量、粗脂肪含量、产油量、油酸、亚油酸影响显著。钾肥的最佳施用时期为基施。油葵产量与盘径、千粒重、出仁率均有显著的正相关关系,油酸和亚油酸之间存在负相关关系。     

培肥措施对侵蚀坡耕地春玉米产量与土壤养分的影响

针对宁南山区坡耕地土壤养分流失严重和作物产量较低的问题,通过剥离表层土壤0、10 cm和20 cm模拟不同侵蚀程度,研究单施化肥(NP)、有机无机配施(M+NP)和单施有机肥(M)、不施肥(CK)4个培肥措施对春玉米产量、耕层土壤有机质、碱解氮、土壤有效磷和土壤速效钾含量的影响,从而提出侵蚀坡耕地增产和培肥效果俱佳的施肥模式。结果表明,相对于CK处理,M和M+NP处理均能改善不同侵蚀程度下坡耕地春玉米的穗长、穗行数、穗粒数和百粒重等农学性状,达到增产目的。随着坡耕地土壤侵蚀程度的增加,春玉米的各产量构成因素和产量都出现显著降低趋势。相对于0 cm土层,表土剥离10 cm和20 cm侵蚀处理下春玉米分别显著减产了26.4%和38.5%。在同等侵蚀条件下,施肥措施能显著增加0~20 cm土壤碱解氮、有效磷和速效钾含量,而对土壤有机质含量影响不大;但随着土壤侵蚀程度的增加,土壤有机质和速效氮、磷、钾养分平均含量呈降低趋势。施用有机肥或有机无机配施还能降低土壤砂粒比例,提高粘粒含量,有效地改善土壤物理结构。     

不同秸秆还田量对旱地土壤水肥和玉米生长与产量的影响

以阜新地区为例,开展不同秸秆还田量对旱地土壤水肥和玉米生长与产量的影响研究。试验设计0 kg·hm^-2,6 000 kg·hm^-2,12 000 kg·hm^-2,18 000 kg·hm^-2、24 000 kg·hm^-2共5个处理,3次重复,共15个小区,小区面积(4 m×15 m)为60 m²。研究结果表明,对照CK不施用秸秆处理,深耕加秸秆的方法,土壤含水量显著增加,除了对照之外,各个处理剂量之间的差异并不明显,且呈先上升而后下降趋势。说明秸秆在土壤中始终处于水分的非饱和状态,并不是秸秆剂量越大越好。各个层次土壤容重与对照相比变化较明显,其中10～20 cm深处土壤容重变化最大,各个处理土壤容重表现出随秸秆还田量增加土壤容重降低值减少的趋势,下降幅度为12 000 kg·hm^-2>6 000 kg·hm^-2>18 000 kg·hm^-2。秸秆还田处理,提高了植物的叶绿素含量,促进了植物的光合效率,以12 000 kg·h m^-2处理较好。不同处理对玉米产量影响差异显著,达到了5%的显著水平,施入量在0～12 000 kg·hm^-2之间,玉米产量呈上升趋势,超过18 000 kg·hm^-2产量呈下降趋势,因此建议推广剂量为12 000 kg·hm^-2。     

The effect of soil type and farm size on the variability of weed infestation in maize (Zea mays L.) fields in the south-west region of Poland

Weeds are a primary factor limiting maize yield. Their occurrence and abundance are affected considerably by environmental factors and farming practices. The variability of weed number in maize depending on the soil type and farm size was investigated. Farms of different sizes vary in farming practices, which affects weediness. Based on this assumption, farm size was considered as indirect factor affecting weed abundance. An investigation of 45 farms that differed in size (5–15 ha, 15–50 ha, >50 ha) and soil type (chernozem, distric cambisol, haplic luvisol) was conducted. Thirteen dominant weed species persistently occurring in maize fields in south-western Poland were examined. Regardless of the soil type and farm size, the most abundant weed species were Echinochloa crus-galli and Chenopodium album. In addition to these species, the most numerous weeds on chernozems were Setaria viridis and Solanum nigrum, while on haplic luvisols and distric cambisols, the most numerous were Viola arvensis and Elymus repens. Additionally, on haplic luvisols, Anthemis arvensis was abundant. Small farms were stronger infested by weeds than large farms due to the implementation of extensive weed-supressing practices, especially low herbicide use. Soil type affected the number of weeds to a greater extent than did farm size.     

灌淤土小麦／玉米间套不同供磷水平群体产量和根系生长形态分析

采用根箱法在不同供磷水平下,对春小麦和玉米在间作和单作情况下的产量和根系形态进行了比较研究。结果表明,适量的供磷能促进小麦、玉米产量的提高,过高反而减少。在施纯P2O50.1 g/kg土(P1)、0.2g/kg土(P2)0、.3 g/kg土(P3)的3个供磷水平下,P2水平和P3水平比P1水平总体产量增长55.09%和40.17%;籽粒产量增长51.28%和56.27%。单作小麦生物产量提高了35.89%~41.11%,穗粒重提高了21.71%~65.79%。随供磷水平的增加,整个根系根重基本上呈现出先增加后减少的趋势,但均高于低磷水平。单作小麦和间作玉米的根长在0~50 cm的土层中随供磷水平的增高,呈增长趋势,相对于低磷水平其增长幅度分别为11.78%~31.16%和39.83%~53.76%,而单作玉米根长呈先增加后减少的趋势。     

沟灌方式和有机肥配合对甜糯玉米产量和土壤有机碳组分及酶活性的影响

为探明有利于提高甜糯玉米鲜穗产量和土壤质量的水肥供应模式,开展了3种有机肥料(牛粪FC、生物有机肥FB和猪粪FP)和2种有机无机N比例(70%无机N+30%有机N(1),60%无机N+40%有机N(2))下,3种沟灌方式(常规沟灌CFI,交替隔沟灌AFI和隔沟灌溉FFI)配合对甜糯玉米产量和土壤有机碳组分及酶活性影响的田间试验。结果表明:FFI时,与FB相比,FC和FP甜糯玉米鲜穗产量分别提高1.6%和2.3%,且FC处理提高土壤易氧化有机碳(ROC)和微生物量碳,FP处理提高土壤可溶性有机碳(DOC)含量。各沟灌方式下,与FC1相比,FC2不同程度提高甜糯玉米鲜穗产量、土壤过氧化氢酶和脲酶活性、有机碳(SOC)、ROC和DOC含量,其中土壤ROC和DOC含量分别提高14.5%~37.9%和24.3%~78.5%。与CFI相比,FC1时,抽雄期AFI和FFI土壤ROC、灌浆期AFI和成熟期FFI土壤DOC显著提高;FC2时,抽雄期FFI土壤有机碳提高10.3%,抽雄期和灌浆期AFI和FFI土壤ROC提高19.8%~31.5%,灌浆期和成熟期FFI土壤DOC分别提高57.9%和26.1%。玉米鲜穗产量与灌浆期土壤脲酶活性、SOC、ROC和DOC,以及SOC与ROC之间呈显著相关关系,其中鲜穗产量与DOC之间相关系数为0.834。因此,60%无机N+40%牛粪N与隔沟灌溉或交替隔沟灌结合是有利于提高甜糯玉米鲜穗产量和土壤质量的水肥供应模式。     

渭北旱塬不同覆盖材料对旱作农田土壤水分及春玉米产量的影响

为了探索半湿润区沟垄覆盖栽培条件下春玉米田的蓄墒效果和增产增收效应,2009—2010年在渭北旱塬采用普通地膜、生物降解膜和液态膜,设置了不同沟垄覆盖栽培模式,连续2a对土壤水分、产量和经济效益进行分析研究。结果表明,在玉米全生育期,普通地膜和生物降解膜能有效改善土壤的水分利用状况。与传统平作(对照)相比,普通地膜和生物降解膜覆盖处理,0~200 cm土壤平均贮水量分别增加了9.2%和8.6%,液态膜覆盖表现不稳定。2 a玉米平均产量普通地膜和生物降解膜分别较对照提高19.23%和17.82%(P<0.05),水分利用效率平均提高21.49%和20.25%;经济效益以普通地膜和生物降解膜最高,2 a平均纯收益分别较对照增收22.09%和20.44%,而液态膜处理的产量、水分利用效率及经济效益与对照均无显著差异。可见,覆盖生物降解膜和普通地膜有良好的蓄水保墒效果,显著增加了作物产量和水分利用效率,因此生物降解膜可以代替普通地膜应用于农业生产。     

播期对玉米生长发育和产量的影响

基于2012—2014年在辽宁省庄河市和锦州市进行的玉米分期播种试验资料,对辽宁地区玉米生长及产能受温度影响情况进行分析。试验分为5个播期,播期间隔10~15 d不等,种植密度约为4.2株·m~(-2),每个播期分为4个重复小区,分别观测玉米生长指标。结果表明:在日照和水分条件适宜的情况下,玉米在各生长发育期所持续的时间与相应期间的温度存在着负相关关系。播种~出苗阶段持续时间在日最低气温15℃以下随着温度升高而逐渐缩短,15℃以上则逐渐增加。吐丝~成熟阶段持续时间则随着播期的延后而延长。玉米在出苗~吐丝阶段,各播期温度条件相当,差别并不显著。吐丝~成熟期≥10℃的活动积温和气温日较差分别在1 500℃·d左右和8℃~8.5℃的范围内对产量的形成更加有利。     

棉隆土壤消毒联合种植密度防除油菜田杂草及对作物产量和田间光照的影响

在农田杂草的治理中,结合农艺措施来治理草害的发生,可有效减少化学除草剂的使用,实现草害的综合治理。本文采用田间试验研究了棉隆土壤消毒联合油菜不同种植密度对油菜田主要杂草野燕麦Avena fatua、苦苣菜Sonchus oleraceus的防除效果,及杂草对氮、磷、钾及水分消耗的影响。结果表明,土壤消毒联合种植密度对油菜田杂草防除效果显著,对野燕麦、苦苣菜均有良好防效,总鲜重防效达到89.8%～100.0%。采取防除措施后,杂草对田间氮、磷、钾和水分的消耗量减少85%以上,有效改善了田间的水肥和光照条件。土壤消毒联合种植密度不同处理的油菜籽产量达到3 155.0～4 920.5 kg/hm2,增产效果显著,产量较未消毒土壤区增加13.3%～76.8%,增收1 857.3～10 684.8元/hm2。研究表明采用土壤消毒结合种植密度对油菜田杂草具有很好的控制效果,适度增加油菜种植密度既能保证对杂草防效,同时也能保证产量。     

海藻酸复合磷肥对玉米产量与土壤养分的影响

研究海藻酸复合磷肥对玉米产量和土壤养分供应强度的影响可为其推广应用提供理论依据。以‘郑单958’品种玉米为材料进行连续2 a的大田试验,设置不施磷肥(CK)、磷酸二铵(DAP)、海藻酸复合磷肥(NI)、海藻酸复合磷肥减量(MI)4个处理,测定玉米产量及生长特性、植株养分含量、土壤养分含量以及磷肥利用率等指标。结果表明：NI处理在2 a间较CK处理显著增产17.1%～24.3%,在第2 a较DAP处理显著增产6.7%,生物量、株高、茎粗与叶绿素含量也显著增加。NI处理叶片全磷含量较CK和DAP处理分别显著增加66.1%和23.4%,且NI与MI处理磷素回收利用率较DAP处理分别显著增加134.5%与89.3%。NI处理土壤有效磷较CK处理在2 a间显著增加30.9%～59.9%,较DAP处理显著增加13.8%～17.2%,DAP与MI处理间无显著差异;不同磷肥处理与年份因素在土壤有效磷和全磷含量上有显著的正交互作用。相关性分析表明,土壤有效磷与玉米的产量、株高、茎粗及其叶绿素含量呈显著正相关。与磷酸二铵相比,海藻酸复合磷肥显著提高了土壤有效磷含量及其磷肥利用率,促进了玉米的生长发育、养分...     

秸秆覆盖量对土壤水分利用及春玉米产量的影响

为了探明半干旱区秸秆覆盖栽培中适宜的秸秆覆盖量,在宁南旱区进行了春玉米栽培试验。试验设1.35、0.9、0.45和0万kg/hm24个覆盖量处理,分析了不同覆盖量对土壤水分、玉米产量及水分利用效率的影响。结果表明,4年玉米生育期覆盖量从高到低0～200 cm土层平均土壤贮水量分别较CK(无覆盖)高15.47、10.79 mm和6.26 mm(P<0.05)。试验期间,2009年玉米生育期降雨量最低(为266.1 mm),各处理依次较CK增产13.10%、17.37%和5.40%(P<0.05);2010年玉米生育期降雨量最高(为433.6 mm),各处理依次较CK增产3.91%、7.58%(P<0.05)和1.70%。0.9～1.35万kg/hm2覆盖量增产效果明显,4年平均比CK增产14.23%～12.03%,水分利用效率提高了10.64%～8.87%。宁南旱区,0.9万kg/hm2秸秆覆盖量能更好地蓄水保墒,促进农田土壤水分良性循环,且对提高玉米产量和水分利用效率有显著效果。     

氮肥和密度对胡麻水分、氮素利用率及产量的影响

在大田环境下,设置氮肥(0、75、150 kg·hm^-2)和密度(4.5、7.5、10.5×10⁶粒·hm^-2)2因素共9个处理(N₀D₁、N₀D₂、N₀D₃、N₁D₁、N₁D₂、N₁D₃、N₂D₁、N₂D₂、N₂D₃)的随机区组试验,分析了不同施氮量和种植密度组合对旱地胡麻土壤含水量、贮水量、籽粒产量及产量构成因子、水分和氮素利用率的影响。结果表明,氮肥、密度各处理土壤含水量变化主要表现在苗期～青果期0～60 cm土层,以N₁D₁处理为优,最高达到15.52%;N₂...     

氮肥深施对旱作覆膜农田土壤养分含量及春玉米产量的影响

以春玉米为供试作物,于2021—2022年在甘肃省定西市进行不同深度施肥田间试验,以双垄沟覆膜种植为基础,设置3个氮肥施用深度：5 cm(D5)、15 cm(D15)和25 cm(D25),以不施氮(N0)处理为对照,共4个处理,分析不同氮肥施用深度对农田土壤养分含量、干物质积累、水分利用及玉米产量的影响,为优化施肥模式和进一步提升其节水增产效能提供理论依据。结果表明,随施肥深度的增加,农田0～40 cm土层土壤养分含量逐渐增大,D25处理较D15和D5处理的土壤有机碳、全氮、速效磷和速效钾含量分别平均提高8.67%、2.23%、22.11%和15.18%;氮肥深施可提高生育后期养分供给能力,玉米干物质积累量显著提高,D25处理播后105 d～收获期干物质积累量分别较D15和D5提高6.53%和25.30%;2个试验年份农田耗水量和水分利用效率均随着施肥深度的增加逐渐增大,D25处理分别较D15和D5平均提高10.09%和10.08%;D25处理玉米生物产量和经济产量较D5处理分别平均提高27.20%和34.93%。在西北旱作区,氮肥25 cm深施模式能为玉米提供更好的养分供给,是提高...     

绿肥与化肥配施对小麦产量和土壤肥力的影响

在甘肃河西绿洲灌区,通过田间试验研究在施氮总量不变的条件下,由绿肥代替相同含氮量的化肥对小麦产量、经济性状、土壤肥力和土壤微生物数量的影响.结果表明,第一年随着绿肥量的增加,小麦产量具有下降趋势,但绿肥收获后各处理的土壤肥力却得到显著增加；第二年随着绿肥量的增加小麦产量依次增加,以70％化肥N+30％绿肥N处理产量最高...