安徽省沿江棉区两种栽培方式下棉田杂草发生与危害研究

初步研究了安徽省沿江棉区直播棉田和移栽棉田杂草发生和危害。运用杂草群落的重要值(MDK)和相对多度(RA),结合K类中心聚类法分析两种模式棉田杂草发生和危害程度。在直播棉田和移栽棉田中,杂草发生种类和杂草演替规律差异不大。一般是以禾本科杂草牛筋草、马唐为重要杂草,由铁苋菜、狗尾草、马齿苋、通泉草、反枝苋和异型莎草等主要杂草组成的杂草群落;直播棉田杂草在棉花蕾期发生密度较大,对棉花的危害程度也较大。两种栽培方式下,不除草棉田的棉花前期株高、叶片数、果枝数和果节数显著低于常规除草棉田;后期的株高、单株铃数、单铃重显著低于常规除草棉田,皮棉产量减少极显著。     

Goosegrass (Eleusine indica) density effects on cotton (Gossypium hirsutum)

Goosegrass is one of the worst agricultural weeds on a worldwide basis. Understanding of its interference impact in crop field will provide useful information for weed control programs. Field experiments were conducted during 2010–2012 to determine the influence of goosegrass density on cotton growth at the weed densities of 0, 0.125, 0.25, 0.5, 1, 2, and 4 plants m–1 of row. Seed cotton yield tended to decrease with the increase in weed density, and goosegrass at a density of 4 plants m–1 of row significantly reduced cotton yields by 20 to 27%. A density of 11.6–19.2 goosegrass plant m–1 of row would result in a 50% cotton yield loss from the maximum yield according to the hyperbolic decay regression model. Boll production was not affected in the early growing season. But boll numbers per plant were reduced about 25% at the density of 4 plants m–1 of row in the late growing season. Both cotton boll weight and seed numbers per boll were significantly reduced(8%) at 4 goosegrass plants m–1 of row. Cotton plant height, stem diameter and sympodial branch number were not affected as much as cotton yields by goosegrass competition. Seed index, lint percentage and lint fiber properties were unaffected by weed competition. Intraspecific competition resulted in density-dependent effects on weed biomass per plant, 142–387 g dry weight by harvest. Goosegrass biomass m–2 tended to increase with increasing weed density as indicated by a quadratic response. The adverse impact of goosegrass on cotton yield identified in this study has indicated the need of effective goosegrass management.     

Effects of plant density and mepiquat chloride application on cotton boll setting in wheat–cotton double cropping system

Sowing cotton directly after harvesting wheat in the Yangtze River Valley of China requires early mature of cotton without yield reduction. Boll-setting period synchronisation and more yield bolls distributed at the upper and middle canopy layers are also required for harvesting. The objective of this study is to quantify the individual and interaction effects of plant density and plant growth regulator mepiquat chloride(MC) on temporal and spatial distributions of yield bolls, as well as yield and yield components. During the 2013–2016 cotton growing seasons, the experiments were conducted on a shortseason cotton cultivar CRRI50 at Yangzhou University, China. Various combinations of plant density(12.0, 13.5 and 15.0 plants m~(–2)) and MC dose(180, 270 and 360 g ha~(–1)) were applied on cotton plants. The combination of 13.5 plants m~(–2) and 270 g ha~(–1) MC resulted in the greatest boll number per unit area, the highest daily boll setting number and more than 90% of bolls positioned within 45–80 cm above the ground. In conclusion, appropriate MC dose in combination of high plant density could synchronize boll-setting period and retain more bolls at the upper and middle canopy layers without yield reduction in the system of direct-seeded cotton after wheat harvest, and thus overcome the labor-intensive problem in current transplanting cropping system.     

Performance of a Variable Tillage System Based on Interactions with Landscape and Soil

Understanding tillage system interaction with landscape variability is important in prescribing appropriate tillage systems that are profitable and environmentally sound. A three-year (1997–1999) study was conducted on a gently sloping, poorly drained lacustrine landscape to evaluate tillage, landscape, and soil interactions on grain yield. Tillage systems investigated were a reduced tillage (RT) system [no-tillage after soybean (Glycine max (L.) Merr), fall chisel plowing after corn (Zea mays (L.) var. mays)], and a conventional tillage (CT) system (fall chisel plowing after soybean and fall moldboard plowing after corn). Fall primary tillage was followed with a pre-plant field cultivation in the spring. Runoff and pollutant losses from the two tillage systems were also measured under a 63 mm h^–1 simulated rainfall. Runoff and pollutant (total solids, chemical oxygen demand, total P, dissolved molybdate reactive P) losses were similar, or lower (6.6, 8.0, 7.7, 5.5, and 4.1 times, respectively) in the RT than the CT system. Tillage system, landscape elevation, and soil type interactions on crop yield varied depending upon whether it was a wet or dry growing season. Using the interactions, soybean yield differences among the modeled fixed-RT, fixed-CT, and variable tillage (VT) systems in a wet year were less than 0.1 Mg ha^–1. During a dry year, corn yield was higher in the RT and the VT systems than in the CT system. When no new purchase of tillage equipment(s) is necessary to implement the RT, VT, or CT system, the modest yield benefits during relatively dry years, plus the improved runoff water quality by using reduced tillage system in all or part of the landscape, would justify the use of RT and VT systems over the CT system in the lacustrine landscape.     

土壤耕层重构与灌水对棉田水分含量及棉花产量性状的影响

为探明土壤耕层重构与灌水对棉花生育性状及产量的影响,采用随机区组设计,于2015和2016年在河北省农林科学院棉花研究所威县试验站设置5个处理,分别是CK(旋耕),常量底墒水(675m~3/hm~2);T1,旋耕,高量底墒水(1 200m~3/hm~2);T2,土壤耕层重构,高量底墒水;T3,土壤耕层重构,高量底墒水,花铃期超量灌水(1 800m~3/hm~2)模拟涝灾;T4,土壤耕层重构,高量底墒水,中后期不灌水;2016年降雨量偏大,各处理只灌底墒水。调查测定不同生育时期不同耕层土壤水分含量、棉花生育性状和产量性状。结果表明:T1在干旱年份(2015年)能提高籽棉产量,在多雨年份(2016年)增产效果不明显。耕层重构提高棉田土壤20cm以下土层蓄水保墒与缓冲调节能力,在暴雨(模拟)条件下不致形成涝灾,在干旱条件下深层土壤水分上移供棉花生长需求。T2棉花苗期与蕾期生长慢,花铃期生长快,具有明显的后发优势,干旱年份(2015年)与多雨年份(2016年)分别较对照籽棉产量增加27.0%与8.7%,T4处理2年较对照分别增产14.6%与10.1%;T3与T2处理2年产量差异均不显著,表现出较强的耐涝能力。土壤耕层重构是棉田节水增产的有效耕作措施,具有抗旱耐涝作用,可有效提高棉花产量。     

反枝苋对棉花的密度竞争作用

【目的】反枝苋是世界性恶性杂草之一,为安徽省沿江棉区主要杂草,而棉花对杂草竞争十分敏感。论文旨在明确反枝苋对棉花的密度竞争影响,为棉田杂草反枝苋的综合防治提供理论依据。【方法】2013—2015年在安徽省安庆市试验地,采用添加系列试验方法,棉花密度保持不变,设置8个反枝苋密度(0、0.125、0.25、0.5、1、2、4、8株/m)与棉花全生育期竞争,研究不同反枝苋密度竞争对棉花生长、子棉产量及其构成因素、纤维品质的影响。【结果】随着反枝苋密度增加,反枝苋株高、茎直径逐渐减小;相对于0.125株/m的反枝苋,反枝苋茎直径分别于1株/m(2013年和2014年)、0.5株/m(2015年)显著降低12.0%—18.6%;反枝苋株高则在2015年于0.5株/m显著减少24.2%。3年数据平均,单位面积反枝苋生物量由1 156.9 kg·hm-2(0.125株/m)逐渐增加到7 524.0 kg·hm-2(8株/m),较高密度反枝苋种内竞争明显。随着反枝苋与棉花竞争时间的延长,反枝苋株高于52—83 DAE(出苗后天数,days after emergence)逐渐超过棉花的,茎直径于18—70 DAE逐渐大于棉花的。在棉花成熟期,反枝苋株高比棉花高35.6—128.2 cm,反枝苋茎直径比棉花粗9.9—24.8 mm。反枝苋在株高和生物量上对棉花具明显优势。随着反枝苋密度增加,棉花株高变化不明显,茎直径明显减小;棉花单株铃数、果枝数和单铃重显著减少,衣分也有一定程度减小。1株/m的杂草密度导致棉花单株果枝数减少4.63%—69.18%,铃数减少20.81%—84.98%,单铃重减少3.04%—20.36%,衣分减少1.54%左右。引起子棉产量显著减产的反枝苋密度分别是0.125株/m(2013年)和0.25株/m(2014年和2015年),导致子棉减产14.0%—33.7%;子棉产量损失率与反枝苋密度符合双曲线模型,据此可预测子棉减产50%的反枝苋密度为0.2—2.8株/m。在反枝苋与棉花竞争91 DAE,0.125—0.5株/m反枝苋可显著减少棉花单株果枝数和铃数。在部分年份,棉纤维的上半部平均长度、马克隆值及断裂比强度随反枝苋密度增加有减小的趋势,且差异显著。【结论】在安徽省沿江棉区,当反枝苋与棉花全生育期竞争时,对反枝苋及棉花的株高影响不明显,对两者的茎直径产生显著影响;随着竞争时间的延长,反枝苋的株高和茎直径逐渐大于棉花的;因而反枝苋在株高和生物量上对棉花具有竞争优势。反枝苋苗期是其防治关键期。当反枝苋密度逐渐增加时,其种内竞争逐渐增强。反枝苋生物量易受环境条件影响,随着反枝苋密度增加,单位面积反枝苋生物量增加,对棉花生长和产量的抑制作用明显增强。反枝苋竞争主要通过影响棉花单株铃数和单铃重而减少棉花产量。推测本地区导致子棉减产5%的反枝苋密度为0.011—0.090株/m。     

Camera steered mechanical weed control in sugar beet,maize and soybean

In sugar beet, maize and soybean, weeds are usually controlled by herbicides uniformly applied across the whole field. Due to restrictions in herbicide use and negative side effects, mechanical weeding plays a major role in integrated weed management (IWM). In 2015 and 2016, eight field experiments were conducted to test the efficacy of an OEM Claas 3-D stereo camera^® in combination with an Einböck Row-Guard^® hoe for controlling weeds. Ducks-foot blades in the inter-row were combined with four different mechanical intra-row weeding elements in sugar beet, maize and soybean and a band sprayer in sugar beet. Average weed densities in the untreated control plots were from 12 to 153 plants m^?2 with Chenopodium album, Polygonum convolvulus, Thlapsi arvense being the most abundant weed species. Camera steered hoeing resulted in 78% weed control efficacy compared to 65% using machine hoeing with manual guidance. Mechanical intra-row elements controlled up to 79% of the weeds in the crop rows. Those elements did not cause significant crop damage except for the treatment with a rotary harrow in maize in 2016. Weed control efficacy was highest in the herbicide treatments with almost 100% followed by herbicide band-applications combined with inter-row hoeing. Mechanical weed control treatments increased white sugar yield by 39%, maize biomass yield by 43% and soybean grain yield by 58% compared to the untreated control in both years. However, yield increase was again higher with chemical weed control. In conclusion, camera guided weed hoeing has improved efficacy and selectivity of mechanical weed control in sugar beet, maize and soybean.     

直播稀植高产杂交棉农艺及冠层结构特征研究

为充分挖掘杂交棉增产潜力,采用大田创建高产试验示范田的方法,以杂交棉稀植为研究对象,以常规棉密植棉为对照,分析棉花产量形成过程中农艺性状、冠层结构指标的变化。结果表明:与常规棉密植相比,杂交棉稀植条件下皮棉产量、单株结铃数和单铃质量分别增加了7.9%～24.1%、34.8%～40.2%和14.3%～19.2%,果枝台数和倒四叶宽分别增加了18.9%、9.6%;且叶面积指数(LAI)和叶倾角(MTA)增幅分别为53.3%、23.9%～26.4%,冠层开度(DIFN)则降低了45.5%～81.1%。杂交棉稀植条件下,与皮棉产量2 500 kg·hm~(-2)棉田相比,3 000 kg·hm~(-2)棉田的单位面积株数、株高、果枝始节高度以及LAI、MTA分别增加了5.1%～15.1%、1～2 cm、2.2%、11.6%、4.8%,DIFN降低了56.7%。籽棉产量与LAI和果枝台数呈显著正相关,株高与总铃数呈显著正相关、MTA与单株结铃数和单铃质量呈显著正相关,DIFN与单位面积株数显著正相关。综上,适度稀植条件下杂交棉充分发挥了杂种优势,棉株个体生长旺盛从而弥补群体的不足,单株铃数和单铃质量的同步提高是其获得高产的主要原因;杂交棉稀植实现皮棉产量3 000kg·hm~(-2)的总铃数大于120×10~4 hm~(-2)、单铃质量大于5.31 g;果枝台数维持在10台,倒四叶宽大于18 cm;在盛铃后期叶面积指数达到峰值为4.3～4.9、MTA为52.7～53.1°、DIFN为0.011～0.015。     

关中西部麦田杂草分布及危害损失

调查结果表明,陕西省关中西部麦田杂草主要有２２种,分属１０科２２属,危害严重的有１０种。６个生态区杂草种类,优势组合分布特点有一定差异,尤以地灌区与塬区旱地存在较大差异。影响杂草分布的因素 地理条件外,还有人为传播,耕作栽培,降雨量,化学除措等。     

不同施氮时期对陆地棉叶片光合特性及产量构成的影响

在已确定棉花施氮总量的基础上,2011年进一步进行了不同施氮时期对陆地棉叶片光合特性和产量构成因素的研究。研究结果表明：在播前施150 kg·hm^-2基肥和花铃期施150 kg·hm^-2追肥的N3处理功能叶片的SPAD值和净光合速率在花铃期以后均处于较高水平,而叶面积指数则表现为蕾期和花铃期各追施150 kg·hm^-2氮肥的N4处理自花铃期保持最高水平,其次为N3处理。N3处理抑制蕾铃的脱落,其蕾铃脱落率分别比N2、N4处理低48.98%和44.44%。各处理皮棉产量以N3处理最高,达1324.7 kg·hm^-2,比施肥各处理的平均产量高出14.9%。     

几种除草剂对苎麻田杂草的防效

为了明确几种除草剂对苎麻田杂草的防除效果,进行了苎麻田除草试验。结果表明:施药后14 d对苎麻田杂草的综合株防效从高到低分别为:24%乙氧氟草醚乳油、90%乙草胺乳油、10%精喹禾灵乳油、10.8%高效盖草能乳油,防效分别为89.3%、88.5%、83.2%、82.9%;在施药后28 d,对杂草的株防效均出现一定程度下降。而对苎麻田杂草的鲜重防效从高到低分别为90%乙草胺乳油、24%乙氧氟草醚乳油、10.8%高效盖草能乳油、10%精喹禾灵乳油,其中90%乙草胺乳油和24%乙氧氟草醚乳油对杂草的鲜重防效分别达到87.1%和86.8%,显著高于10.8%高效盖草能乳油和10%精喹禾灵乳油。     

Enhancing boll protein synthesis and carbohydrate conversion by the application of exogenous amino acids at the peak flowering stage increased the boll Bt toxin concentration and lint yield in cotton

In Bacillus thuringenesis (Bt) transgenic cotton, the cotton boll has the lowest insecticidal protein content when compared to the other organs. The present study investigated the effects of amino acid spray application at the peak flowering stage on the cotton boll Bt toxin concentration and yield formation. Boll protein synthesis and carbohydrate conversion were also studied to reveal the fundamental mechanism. Three treatments (i.e., CK, the untreated control; LA1, five amino acids; LA2, 21 amino acids) were applied to two Bt cultivars of G. hirsutum (i.e., the hybrid Sikang 3 and the conventional Sikang 1) in the cotton-growing seasons during 2017 and 2018. Amino acid spray application at the peak flowering stage resulted in an increase of 5.2–16.4% in the boll Bt protein concentration and an increase of 5.5–11.3% in the seed cotton yield, but there was no difference between the two amino acid treatments. In addition, amino acid applications led to increases in the amino acid content, soluble protein content, glutamate pyruvate transaminase (GPT) activity, glutamate oxaloacetate transaminase (GOT) activity, glucose content, fructose content and soluble acid invertase (SAI) activity. This study also found that Bt protein content, enhanced boll number and the weight of opened bolls were closely related to carbon and nitrogen metabolism. The Bt protein content had significant linear positive correlations with amino acid and soluble protein contents. Enhanced boll number had significant linear positive correlations with the GPT and GOT activities from 15–25 days after flowering (DAF). The weight of opened bolls from 55–65 DAF had a significant linear positive correlation with the SAI activity. These results indicate that the enhancement of boll protein synthesis and carbohydrate conversion by amino acid application resulted in a simultaneous increase in the boll Bt protein concentration and cotton lint yield.     

鄂杂棉10号产量构成因素及增产途径分析

对鄂杂棉10号的产量构成进行分析,结果表明:杂交棉产量构成因素中以成铃数对产量的正向作用最大,单铃重次之,衣分最小。因此,杂交棉鄂杂棉10号高产的主攻目标是增加成铃数,兼顾单铃重。     

几种除草剂防除棉田杂草马唐试验

采用二甲戊灵EC和氟乐灵EC两种土壤处理荆,精喹禾灵EC、高效氟吡甲禾灵EC和15%精吡氟禾草灵EC 3种茎叶处理荆对棉田主要杂草马唐进行了防除试验.结果表明,各处理对棉花没有药害,高剂量的除草剂对马唐的防效基本一致,但是低剂量的精喹禾灵防效显著地优于其它除草剂:用该5种除草剂防除棉田杂草马唐,棉花增产效果显著,同时节省人力,降低成本,从而达到节本增效的目的.     

Soil tillage methods by years interaction for dry matter of plant yield of maize (Zea mays L.) using additive main effects and multiplicative interaction model

The objective of this study was to assess soil tillage methods by years interaction for dry matter of plant yield of maize(Zea mays L.) grown in West Poland by the additive main effects and multiplicative interaction model. The study comprised four soil tillage methods, analysed in 12 years through field trials arranged in a randomized complete block design, with four replicates. Dry matter of plant yield of the tested soil tillage methods varied from 86.7 dt ha~(–1)(for no-plough tillage in 2005) to 246.4 dt ha~(–1)(for complete conventional tillage in 2012), with an average of 146.6 dt ha~(–1). In the variance analysis, 49.07% of the total dry matter of plant yield variation was explained by years, 12.69% by differences between soil tillage methods, and 10.53% by soil tillage methods by years interaction. Dry matter of plant yield is highly influenced by soil tillage methods by years factors.     

不同生态区杂交棉皮棉产量与多个性状关系的研究

[目的]研究不同生态区杂交棉在南疆地区皮棉产量与多个性状的关系,为新疆南疆地区棉花引种、育种和大田生产提供理论和生产实践参考.[方法]以来自不同生态区12个杂交棉品种(系)为材料,分别研究皮棉产量与单株铃数、单铃重、衣分、亩株数(667 m2株数,下同)、籽指、衣指、绒长、纤维伸长率、整齐度指数、马克隆值和断裂比强度之间相关性和通径分析.[结果]皮棉产量与衣分,单株铃数和单铃重达显著正相关;对皮棉产量贡献较大的因子依次是单铃重＞亩株数(667 m2株数,下同)＞单株铃数＞衣分;12份材料,综合表现较好的为湘江棉5号、鲁棉研40号和湘江棉3号.[结论]栽培上杂交棉种植应注意控制合理密度;育种上宜主要从提高衣分、单株铃数和单铃重三方面来提高皮棉产量,同时对品质性状也不能忽视;引种时要注意选择皮棉产量较高,同时纤维品质较好的品种用于当地推广.     

热除草技术现状和展望

除草剂的广泛使用引发了环境污染、生物多样性减少、杂草群落变迁和杂草抗药性等诸多问题。热除草方法是替代化学除草的潜在方法,热除草方法有火焰除草、热水除草、蒸汽除草、红外辐射除草、激光除草等。热除草是快速加热植物体内的水分使植物细胞破裂失去活性、死亡的方法。各种热除草技术的传热机制不同。重点介绍了各种热除草技术的机理和在国内外的发展现状及所适用的环境和发展方向。随着有机农作的发展,热除草技术将发展成熟并得到广泛应用。     

油-棉连作棉田油菜秸秆覆盖对棉田杂草发生及土壤杂草种子库的动态影响

在安徽省沿江棉区开展了油菜秸秆覆盖对棉田杂草发生、棉花生长及土壤杂草种子库影响的研究。结果表明,随着油菜秸秆覆盖量的增加,对棉田杂草的抑制效果增强。与未覆盖秸秆且不除草处理相比较,7000Kg/hm²秸秆覆盖量处理棉花单株铃数和子棉产量显著提高。7000Kg/hm²秸秆覆盖量处理在覆盖后30d、60d和120d逐步减少0-20cm土层杂草种子库密度,与全程除草剂处理较一致;随着覆盖量减少,对0-20cm土层杂草种子库密度降低幅度减小。全程除草剂处理降低0-5cm土层杂草种子库多样性,而油菜秸秆覆盖则可能增加0-5cm土层的杂草种子库多样性。3500Kg/hm²覆盖量+秸秆覆盖30d后喷施除草剂处理的抑草效果和增产效果与全程除草剂处理一致。因此,在安徽省沿江棉区油-棉连作棉田推荐使用3500Kg/hm²油菜秸秆覆盖量+秸秆覆盖30d后喷施除草剂。     

低酚棉的丰产育种目标及方法

本文综述了低酚棉育种的国内外研究动态及其进展,着重讨论了有关低酚棉产量及产量构成因素的育种问題。资料表明,随着遗传背景的不断改良,低酚棉与高酚棉的产量差异正在逐渐缩小,许多品种都已赶上甚至超过推广品种。本文提出了在主攻低酚棉产量时,应着重注意提高衣分,并注意单株铃数、铃重、烂铃率和单株结铃性的改良。提高衣分,应在确保较大籽指的基础上,通过提高衣指来实现提高衣分育种目标。另外,本文还对低酚棉的几种育种方法进行了讨论。     

沿江棉区杂交抗虫棉高产优质种植密度研究

[目的]研究在不同种植密度下棉花生长状况、棉铃特征和产量变化,为沿江棉区找寻高产优质的合理种植密度提供理论参考。[方法]以湘杂棉8号为试验材料,起始密度为12000株/hm2,密度梯度为9000株/hm2,共设6个处理。研究其生长周期、产量、棉铃、棉纤维等特征变化。[结果]密度对棉花的株高和其各生长周期影响不大,不同密度处理中籽棉衣分、纤维品质差异不明显,但对单铃重、＂三桃＂分布、蕾铃脱落率、僵烂比及产量等均有较大影响,且差异显著。基本规律为：棉花单铃重和伏桃比随着种植密度增加而降低,脱落率和僵烂比随着密度增加而增加;但都在处理5时表现最差。皮棉产量以处理2、3和4较高,最高的为处理3,密度最低的处理1产量最低。[结论]通过试验数据分析,在沿江棉区种植杂交抗虫棉以30000株/hm2的种植密度最佳。