Phosphorus Nutrient Characteristics of Different Maize (Zea mays L.) Inbreds for Tolerance to Low-P Stress

Phosphorus nutrient characteristics of different maize inbred lines to low-P stress were studied at stages of seedling, steming, earing, silking under pot culture. In the periods of seedling and steming, P uptake efficiency was the main contributor to P tolerance, and the relative P content in P-tolerant genotypes, 99180 and 99239 were higher than that in sensitive genotype, 99152. At earing stage, P-tolerant genotypes, compared to P-sensitive ones, had higher accumulation of P in upper leaves. When came to the silking stage, P uptake and redistribution efficiency of P-tolerant genotypes were higher than those in 99152. The results also suggested that there are different mechanisms of P nutrient uptake and distribution in different P-tolerant genotypes. Inbred line 99239, according to the investigation, was considered as an efficient stock in the P-uptake while 99180 fallen to the efficient stock of P redistribution.

Effects of Floating Ring Bearing Manufacturing Tolerance Clearances on the Dynamic Characteristics for Turbocharger

The inner and outer oil film dynamic characteristic coefficients of floating ring bearings（FRBs） change due to the manufacturing tolerance of the floating ring, journal and intermediate, which leads to high-speed turbocharger＇s vibration too large and even causes nonlinear vibration accident. However, the investigation of floating ring bearing manufacturing tolerance clearance on the rotordynamic characteristics is less at present. In order to study the influence law of inner and outer clearance on turbocharger vibration, the rotor dynamic motion equations of turbocharger supported in FRBs are derived by analyzing the size relations between floating ring, journal and intermediate for the inner and outer oil film clearances, the time transient response analysis for combination of FRBs clearance are developed. A realistic turbocharger is taken as a research object, the FE model of the turbocharger with FRBs is modeled. Under the conditions of four kinds of limit state bearing clearances for inner and outer oil film, the nonlinear transient analyses are performed based on the established FE dynamic models of the nonlinear rotor-FRBs system applied incentive combinations of gravity and unbalance force, respectively. From the waterfall, the simulation results show that the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different under the four kinds of bearing manufacturing tolerance limit clearances, and fractional frequency does not appear in the turbocharger and the amplitude is minimum under the ODMin/IDMax bearing manufacturing tolerance clearances. The turbocharger vibration is reduced by controlling the manufacturing tolerance clearance combinations of FRBs, which is helpful for the dynamic design and production-manufacturing of high-speed turbocharger.

Macrosomia in non-gestational diabetes pregnancy:glucose tolerance test characteristics and feto-maternal complications in tropical Asia Pacific Australia

Objective:To look into the glucose tolerance test characteristics and determine complications in non-gestational diabetes pregnant subjects.Methods:From 2006 to 2009 all non-gestational diabetes mellitus(non-CDM)pregnant women who delivered macrosomia at the North Australia's Townsville Hospital were retrospectively reviewed by extracting data from clinical record.Glucose tolerance tests results were analysed in the light of an earlier diagnosis of non-GDM.Results:Ninety-one non-CDM mothers with macrosomia were studied and compared with 41normoglycemic subjects without macrosomia.Of the subjects with non-GDM macrosomia,45(49.4%)had normal SO g glucose challenge test(GCT)without further testing,another 8(8.8%)had abnormal GCT but normal 75 g oral glucose tolerance test(OGTT).A total of 4(4.4%)subjects had normal GCT and OGTT.Interestingly.14 out of 16(87.5%)subjects who were tested with OGTT owing to past history of macrosomia had normal results but delivered macrosomic babies.Only 12 subjects had both GCT and OGTT,the rest of the cohort had either of the two tests.Subjects with non-CDM macrosomia had higher frequency of neonatal hypoglycaemia 34%as compared to 10%in nonmacrosomic babies(P=0.003).Other feto-maternal complications were similar in both groups.Conclussions:No significant pattern of glucose tolerance characteristics was identified in nonGDM mothers with macrosomic babies.In spite of being normoglycemic significant neonatal hypoglycaemia was recorded in non-GDM macrosomic babies.Further prospective studies on a larger population are needed to verify our findings.

Effect of Coat Characteristics on Physiological Traits and Heat Tolerance of West African Dwarf Sheep in Southern Nigeria

This experiment was conducted to investigate the effect of coat characteristics on physiological traits and heat tolerance of dwarf sheep in southern Nigeria. A total number of twenty West African dwarf male sheep with an average weight of 9.00 ± 0.52 kg and aged 10 months old were used for the experiment. The dwarf sheep were assigned to four treatment groups in a completely randomized design with five sheep per treatment group. The compared treatment groups were TA (black coat colour sheep with low coat depth and short hair length), TB (black coat colour sheep with high coat depth and long hair length), TC (light brown coat colour sheep with low coat depth and short hair length) and TD (light brown coat colour sheep with high coat depth and long hair length). The results obtained in the study showed that midday was significantly (P 0.05) affected by morning, midday and evening. Rectal temperature (40.09℃), respiratory rate (21.01 breaths/min), pulse rate (87.49 beats/min), heat tolerance coefficient (97.10%), haemoglobin (9.04 g/l), blood cell (10.84 × 106/μl), white blood cell (12.06 × 106/μl) and glucose (50.10 mg/dl) were significantly (P 0.05) did not occur in total protein, albumin and globulin among treatment groups. It is concluded that coat characteristics have significant effects on physiological indices and heat tolerance in Nigeria.

A Comparative Study on Pb Tolerance and Enrichment Characteristics among Different Species of Compositae

In order to find landscape plants purifying Pb pollution of soil,a pot experiment was conducted to study Pb resistance and enrichment characteristics of six species of Compositae plants( Aster ageratoides,Rudbeckia hirta,Cosmos sulphureus,Gynura bicolor,Calendula officinalis,Bidens pilosa) in different soil Pb concentrations. The results showed that the dry weight of aboveground part in the six plants decreased with the increase of soil Pb concentration. The tolerance index( TI) of C. sulphureus,G. bicolor and C. officinalis was greater than 0. 5 in all concentrations,and the root tolerance index( RTI) was greater than 0. 9,which were better resistant to Pb stress. The maximum Pb content in aboveground part of R. hirta was 1 783 mg/kg,and the enrichment and transport coefficients were all greater than 1. When the soil Pb concentration was 500 mg/kg,the total Pb accumulation in the aboveground part of R. hirta was 2. 507 mg/plant. Finally based on the integrated observation of the enrichment coefficient,transport factor and repair potential index,it believed that R. hirta can be used to restore Pb contaminated soil at low concentration.

Quality Characteristics Distribution and Its Simulation Based on Asymmetric Tolerances

The application of normal distribution for quality characteristics has its limits on the condition that specification interval is asymmetric. In this paper, the compound normal distribution N(L,σ12,σ22) was proposed and simulated, the property of the parameters Lσ1 and σ2 was studied. The distribution was further applied toangle quality process control.

Experimental study on the effects of climatic characteristics on people's adaptability to thermal environment

In order to find out how the climatic characteristics affect people＇s adaptability to thermal environments,experimental studies in a climate chamber are conducted on the effects of transition seasons（from spring to summer）and the occupants＇ native areas on indoor thermal sensations.Results reveal that people＇s tolerances to cool and warm indoor environments are different in the transition season.When the outdoor temperature is higher,the occupants have a weaker tolerance to a cool indoor environment,but a stronger tolerance to a warm indoor environment.Besides,it is found that the occupants＇ thermal sensations depend on both the climatic characteristics of the season and their native areas.The people from southern China present a greater tolerance to both warm and cool indoor environments than those from northern China.The reason can be explained according to the occupants＇ adaptability to the climatic characteristics and the indoor thermal environments of their native areas in different climate zones.

Effects of High Temperature Stress on Microscopic and Ultrastructural Characteristics of Mesophyll Cells in Flag Leaves of Rice

The microscopic and ultrastructural characteristics of mesophyll cells in flag leaves of two rice lines （a thermosensitive line 4628 and a thermo-resistant line 996） under high temperature stress （37℃ during 8：00-17：00 and 30℃ during 17：00-8：00） were investigated using an optical and a transmission electron microscopy. The membrane permeability and malondialdehyde content increased under the high temperature stress, and the increase of both variables was greater in the line 4628 than in the line 996. Under the high temperature stress, the line 996 showed tightly arranged mesophyll cells in flag leaves, fully developed vascular bundles and some closed stomata, whereas the line 4628 suffered from injury because of undeveloped vascular bundles, loosely arranged mesophyll cells and opened stomata. The mesophyll cells in flag leaves of the line 4628 were severely damaged under the high temperature stress, i.e. the chloroplast envelope became blurred, the grana thylakoid layer was arranged loosely and irregularly, the stroma layer disappeared, many osmiophilic granules appeared within the chloroplast, the outer membrane of mitochondria and the nucleus disintegrated and became blurred, the nucleolus disappeared, and much fibrillar-granular materials appeared within the nucleus. In contrast, the mesophyll cells in flag leaves of the line 996 maintained an intact ultrastructure under the high temperature stress. From these results, it is suggested that the ultrastructural modification of the cell membrane system is the primary plant response to high temperature stress and can be used as an index to evaluate the crop heat tolerance.

Shoot and root traits in drought tolerant maize(Zea mays L.) hybrids

This study aimed to investigate the differences in shoot and root traits, and water use and water use efficiency（WUE） in drought tolerant（DT） maize（Zea mays L.） hybrids under full and deficit irrigated conditions. A two-year greenhouse study was conducted with four hybrids（one conventional hybrid, 33D53AM, two commercial DT hybrids, P1151 AM, N75H, and an experimental hybrid, Exp HB） grown under two water regimes（I（100） and I（50）, referring to 100 and 50% of evapotranspiration requirements）. Under water stress, the hybids P1151 AM, N75, and Exp HB showed more drought tolerance and had either greater shoot dry weight or less dry weight reduction than the conventional hybrid（33 D53 AM）. However, these three hybrids responded to water stress using different mechanisms. Compared with the conventional hybrid, the two commercial DT hybrids（P1151 AM and N75H） had a smaller leaf area, shoot dry weight, and root system per plant. As a result, these hybrids used less water but had a higher WUE compared with the conventional hybrid. In contrast, the experimental hybrid（ExpHB） produced more shoot biomass by silking stage at both irrigation levels than all other hybrids, but it had relatively lower WUE. The hybrids demonstrated different drought response mechanisms that may require different irrigation management strategies. More investigation and validation are needed under field conditions and in different soil types.

Neutronic analysis of silicon carbide cladding accident-tolerant fuel assemblies in pressurized water reactors

In resonance with the Fukushima Daiichi Nuclear Power Plant accident lesson, a novel fuel design to enhance safety regarding severe accident scenarios has become increasingly appreciated in the nuclear power industry. This research focuses on analysis of the neutronic properties of a silicon carbide(SiC) cladding fuel assembly, which provides a greater safety margin as a type of accident-tolerant fuel for pressurized water reactors. The general physical performance of SiC cladding is explored to ascertain its neutronic performance. The neutron spectrum, accumulation of ^(239)Pu, physical characteristics,temperature reactivity coefficient, and power distribution are analyzed. Furthermore, the influences of a burnable poison rod and enrichment are explored. SiC cladding assemblies show a softer neutron spectrum and flatter power distribution than conventional Zr alloy cladding fuel assemblies. Lower enrichment fuel is required when SiC cladding is adopted. However, the positive reactivity coefficient associated with the SiC material remains to be offset. The results reveal that SiC cladding assemblies show broad agreement with the neutronic performance of conventional Zr alloy cladding fuel. In the meantime, its unique physical characteristics can lead to improved safety and economy.

Grey Correlation Analysis of Physiological Traits Related to Drought Tolerance in Pennisetum sp.

The drought resistance of Pennisetum sp. was analyzed under different drought stress conditions simulated by various concentrations of PEG-6000. Changesofa series of indexes such as chlorophyll content, water content, relative electrical conductivity of osmotic solution, MDA content, proline content, soluble polysaccharide content and soluble protein content in the leaves were measured.The correlation of these indexes with the drought resistance of Pennisetum sp. was an- alyzed by the method of grey correlation analysis. The results showed that the chlorophyll, water content, relative electrical conductivity and soluble protein con- tentexhibited obvious negative correlation with the stress concentration, which de- creasedfollowing the increase of PEG-6000 concentration. The soluble polysaccha- ride contentshowed an increasing trend,the MDA content showed a rise at first fol- lowed by a declinetrend, while the prolinecontent was just opposite to MDA. The changes of the 3 indexes showed obvious positive correlation with thestress con- centration. The correlation of these indexes with the drought resistance of Pennise- tum sp. were ranked as follows： leaf water content （0.980 8）, chlorophyll content （0.967 9）, MDA content （0.876 0）, soluble polysaccharide content （0.839 5）, soluble protein content（0.827 5）, relative electrical conductivity of osmotic solution（0.670 8）, and proline content（0.571 3）.

Discussion on dynamic reliability tolerance design technology of electromagnetic relay

Reliability tolerance design of electromagnetic relay during its design period plays an essential role in guaranteeing the consistencies of reliability and output characteristic. The reliability tolerance design can ensure that the products would work well under the influence of disturbing factors (including internal interference, external interference, and machining dispersion). Com- pared with static characteristic, dynamic characteristic of electromagnetic relay can describe its operating process better. This article researches influence of the three kinds of disturbing factors on the dynamic characteristic of electromagnetic relay based on calculating dynamic characteristic. Then, the dynamic reliability tolerance design method of electromagnetic relay is discussed considering three kinds of disturbing factors. Conclusions reached can help to assure the reliability of electromagnetic relay from the beginning of design.

澳洲坚果种质资源耐热性调查与分析

随着全球气候变暖,在夏季持续高温干燥天气下,我国广东、广西澳洲坚果产区不耐热的澳洲坚果种质新梢叶片出现黄化现象,直接或间接影响光合作用,进而影响产量和品质。为了筛选耐热种质应对气候变化,以位于广东省湛江市的国家热带果树种质资源(澳洲坚果)圃内的145份种质资源为试材,调查不同种质的耐热性,分析比较不同程度热敏感种质的生理特性。结果表明,湛江地区6-7月下半昼(12:00-18:00)和上半夜(18:00-24:00)经历了6次较长时间的气温高峰和湿度低谷,导致热敏感种质新梢叶片黄化。不同种质新梢叶片黄化程度因其热敏感程度不同而异,供试145份种质可划分为耐热、轻度热敏感、中度热敏感、重度热敏感种质4类。随着种质热敏感程度的加剧,叶片的叶绿素(叶绿素a+叶绿素b、叶绿素a、叶绿素b)含量均显著下降而呈现褪绿黄化;超氧阴离子自由基(O_(2)^(-))大量积累,脂氧合酶(LOX)活性显著增强,丙二醛(MDA)含量显著增加,表明由活性氧积累引发的细胞膜脂过氧化加剧。与耐热种质相比,轻度热敏感种质的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性显著增强;随着热敏感程度加剧,中度热敏感种质和重度热敏感种质的SOD活性均显著低于耐热种质,POD活性仍显著增强,而中度热敏感种质和重度热敏感种质的CAT活性无显著性差异,表明细胞抗氧化代谢失调。

基于机-电-磁-流整体耦合的油阻尼断路器保护特性的容差设计

油阻尼断路器的主要特点是在电路发生短路、过载等情况时能够自动脱扣,断开电路,从而保护人员和设备的安全,常用于变电站等场所。文章在以往对油阻尼断路器油阻尼力、电磁铁静态特性、操作机构性能等研究的基础上,构建一个基于机-电-磁-流多体多自由度多场耦合的一体化虚拟样机整体耦合模型;接着对该整体耦合模型的保护特性进行了仿真与分析,通过仿真得到了不同电流倍数下动触头的分断特性,并通过实验验证了整体耦合模型和仿真结果的正确性;最后,为减小产品保护特性的分散程度,提高油阻尼断路器的稳定性,文中结合稳健容差设计技术,选取不同电流倍数下触头的断开时间作为目标函数,以极靴半径、细铁芯半径、粗铁芯半径、粗铁芯高度作为关键设计参数,通过正交试验和贡献率分析法对目标函数进行容差分配,使得触头断开时间的分散度比原来减少39.165%。研究成果将会对电器产品的研发提供理论指导。

光伏低压直流断路器电磁脱扣器静态特性分析

对于光伏发电系统的保护,低压直流断路器具有举足轻重的地位。文章对光伏低压直流断路器电磁脱扣器的静态特性进行了分析,在有限元分析软件ANSYS中建立了电磁脱扣器的三维模型,并进行加载、求解,从而得到了不同电流、不同气隙下动铁心所受电磁吸力大小的二维静态特性曲线图。之后对有限元分析软件ANSYS进行了二次开发,得到了动铁心所受电磁吸力在不同结构参数下的变化曲线并给出了相应的解释,同时根据结构参数变化对初始位置电磁吸力的影响为各参数提出了相应的公差建议。

盐胁迫对平欧杂种榛根系生理生化特性的影响

以2年生平欧杂种榛‘达维’为试验材料,在水培条件下设置对照、轻度、中度和重度盐胁迫处理(NaCl浓度分别为0、50、100和200 mmol·L^(-1)),研究不同胁迫时间(1、3和7 d)下根系渗透调节物质、膜伤害程度、抗氧化酶活性以及离子特征的变化,探讨耐盐的生理机制。结果表明:盐胁迫显著促进了可溶性糖(SS)和脯氨酸(Pro)的积累。SS随着胁迫时间的延长呈持续增加趋势,Pro在重度胁迫至3 d时显著升高,较胁迫1 d时提高25.9%。相对电导率(REC)和丙二醛(MDA)随着盐胁迫程度的增强均呈不断升高,重度胁迫下二者较对照分别显著提高32.1%和55.6%。REC和MDA随着胁迫时间的延长呈不断升高。随着盐胁迫程度的增强,超氧化物歧化酶(SOD)表现为先下降后上升,过氧化氢酶(CAT)呈不断增加。SOD和CAT对盐胁迫的响应存在时间差异,二者分别在胁迫7和1 d时达到最大值。随着盐胁迫程度的增强,Na^(+)不断升高,K^(+)波动下降,w(K^(+))∶w(Na^(+))表现为不断下降。平欧杂种榛具有一定的耐盐性。轻度胁迫下,幼苗可以通过自身生理生化特性的调节以响应和适应盐胁迫;中度胁迫下,根细胞膜开始受到伤害,但仍能通过积累渗透调节物质和增强抗氧化酶活性来应对盐胁迫;当NaCl浓度达到200 mmol·L^(-1)且胁迫超过3 d时,植物开始遭受盐害。SS、Pro、CAT活性和Na^(+)质量分数可作为平欧杂种榛耐盐性评价的参考指标。

高效氟氯氰菊酯降解菌的分离与降解特性研究

[目的]筛选降解高效氟氯氰菊酯(β-CF)的微生物菌种资源,并研究其降解特性。[方法]利用梯度压力驯化法,从曾使用拟除虫菊酯类杀虫剂的土壤中富集筛选降解β-CF的候选菌株,通过形态学和基于16S rRNA基因序列系统发育分析鉴定其分类地位,采用单因素试验研究菌株对β-CF的耐受性和降解特性。[结果]筛选获得1株以β-CF为唯一碳源生长、环境适应能力强的细菌GM4,经鉴定该菌为嗜油不动杆菌(Acinetobacter oleivorans)。菌株GM4对β-CF的耐受浓度可以达到600 mg/L,在初始浓度50 mg/L、pH 8.0、接菌量10%、温度28℃条件下培养48 h后,对β-CF降解率为99.44%。[结论]菌株GM4能高效降解β-CF,是环境中β-CF类农药残留生物修复的优良种质资源。

‘光谱’月季对Cd、Zn的富集特征和耐性机制

为进一步研究月季对Cd、Zn的富集特征和耐性机制,以‘光谱’月季(Rosa‘Spectra’)为研究对象,采用盆栽污染模拟试验,研究不同Cd含量(0、25、50、100、200 mg·kg^(-1))和Zn含量(0、500、1000、1500、2000 mg·kg^(-1))单一胁迫下‘光谱’月季的生物量和生理指标变化,以及重金属积累转运机制。结果表明:低含量Cd、Zn处理促进‘光谱’月季的生长,随着处理含量的增加‘,光谱’月季生长受到抑制,但都未致死。‘光谱’月季体内吸收的Cd、Zn主要积累在根系,含量分别为68.48、918.74 mg·kg^(-1),其中Cd主要以NaCl提取态存在,占比为25.19%~60.80%,Zn主要以HAc提取态和去离子水提取态存在,占比分别为20.20%~46.65%和12.69%~29.33%。随处理含量的增加,Cd、Zn处理组都提高了毒性较低的提取态占比,以减弱Cd、Zn对植物根系的毒害。根系中的Cd、Zn均主要富集在细胞碎屑组分,占比分别为55.01%~77.38%、52.35%~63.17%,其次是金属富集颗粒组分和热稳定蛋白组分。随处理含量的增加,‘光谱’月季根系内的Cd、Zn表现出向可溶性组分转移的特征。Cd、Zn处理下,‘光谱’月季根系细胞中均出现黑色颗粒物质,且其密度随着处理含量的增加而增大。根系细胞壁上与Cd、Zn结合的官能团均是羟基、氨基。研究表明,通过根部吸收限制、细胞壁固定、液泡区隔化将Cd、Zn转化为低活性的形态赋存,以及用细胞壁上的羟基、氨基提供结合位点,可能是‘光谱’月季应对Cd、Zn胁迫的重要机制。

土壤改良剂对盐碱地万寿菊生长生理特性的影响

【目的】探究不同土壤改良剂对盐碱地万寿菊(Tagetes erecta)不同生育时期生长生理特性的影响。【方法】采用室内盆栽的方法,以兰州新区在中度盐碱地种植的万寿菊为研究对象,分析不施改良剂(CK),施过磷酸钙+硫酸亚铁(T1)、磷石膏(T2)和微生物菌剂(T3)4个处理对万寿菊3个生育时期生长生理特性的影响,并结合主成分分析和隶属函数,就3个时期对4个处理的改良效果进行评价。【结果】施用过磷酸钙+硫酸亚铁提高万寿菊叶片中的POD活性;施用磷石膏可以提高万寿菊的株高和叶片的POD活性;施用微生物菌剂能提高万寿菊的茎粗与叶片中的POD、CAT活性,叶片中的POD活性与对照相比差异显著(P<0.05)。通过主成分分析将施用改良剂处理下万寿菊的8个差异显著的指标归纳成2个主成分,累积贡献率达到92.5%;得到万寿菊的改良效果评价的主要指标:株高、茎粗、分枝数、丙二醛(MDA)、过氧化物酶(POD)和过氧化氢酶(CAT),通过隶属函数值评定不同处理下不同生育时期万寿菊的耐盐性强弱顺序为:拔节期,T3>T1>CK>T2;现蕾期,CK>T1>T3>T2;初花期,T1>T3>CK>T2。综合比对4种处理在中度盐碱地改良效果,由强到弱依次为微生物菌剂>过磷酸钙+硫酸亚铁>磷石膏>CK。【结论】施用效果最好的改良剂为微生物菌剂。本研究为园林植物在盐碱地绿化的应用方面提供了理论基础。

盖草能对不同花卉品种种子萌发特性的影响

以雏菊(Bellis perennis)、翠菊(Callistephus chinensis)、蛇鞭菊(Liatris spicata)、矢车菊(Centaurea cyanus)、白晶菊(Chrysanthemum paludosum)和硫华菊(Cosmos sulphureus)花卉种子为试材,采用不同浓度盖草能溶液处理种子,研究除草化学药剂对花卉种子萌发特性的影响,比较6种花卉种子的耐药性,以期为科学用药提供参考依据。结果表明:在试验浓度范围内,翠菊、雏菊种子在1.5 mg·L^(-1)盖草能处理下,对发芽率、发芽势、发芽指数无抑制作用;蛇鞭菊在1.0 mg·L^(-1)盖草能处理下,对发芽率和发芽指数无抑制,而发芽势则在0.5 mg·L^(-1)浓度下才未受到影响;矢车菊、硫华菊种子萌发受抑制作用明显,发芽率、发芽势、发芽指数显著降低;在不同处理下进行不同品种的综合比较,翠菊和雏菊的萌发指标均显著高于其他4个品种;翠菊种子发芽时间无延迟效果,雏菊和白晶菊影响只延迟了1 d,蛇鞭菊、矢车菊、硫华菊种子发芽时间随着浓度的升高而延迟,在1.5 mg·L^(-1)浓度处理下分别延迟了2、3、2 d;盖草能对翠菊起到促根抑芽的效果,幼芽比根对盖草能更敏感;当这6种草花种子芽长开始生长后均受到不同程度的抑制,这说明在草花种子后期发芽后,不宜再喷施盖草能除草剂防除杂草。综上所述,雏菊、翠菊种子萌发阶段属于盖草能耐受性品种,播种萌发期的适宜浓度是1.5 mg·L^(-1)以下;蛇鞭菊次之,播种萌发期的适宜浓度是0.5 mg·L^(-1)以下;白晶菊、矢车菊、硫华菊对盖草能极度敏感,不能使用盖草能作为芽前除草剂。