华北地区夏玉米田马唐治理的生态经济杀除阈期研究   总被引：1，自引：1，他引：1  

姜德锋  由振国  李孙荣 《植物保护学报》1997,24(1):89-94

作者于1992～1994年研究夏玉米田马唐(Digitaria sanguinalis L.)治理的生态经济阈期,借助计算机进行数学模拟,建立夏玉米的相对产量与马唐的相对干扰生长时间、相对出苗时间的函数关系。苗后马唐干扰生长的相对时间即相对天数(Xu)与夏玉米相对产量(Yu)的关系式为: Yu=101.5/{1.0 0.01756EXP[—(—0.0876Xu 0.0004888Xu~2)]}…………(1)苗后马唐出苗的相对时间与玉米相对产量的关系式为: Yd=100.73/{1.0 0.96EXP[—(0.06346Xd-0.00006859Xd~2)]}……………(2) 根据生态经济杀除阈期的定义和(1)、(2)两公式计算可知:夏玉米田马唐防除的生态经济杀除阈期的始期应从夏玉米苗后生育期总天数的11.8％开始,结束于夏玉米苗后生育期总天数的53.9％。例如华北地区夏玉米全生育期总天数一般是95天,夏玉米苗后生育期总天数(T)约为88天,故夏玉米田马唐防除的生态经济杀除阈期约在夏玉米苗后10.6—47.5天之间。  相似文献   

Phaeosphaeria sp.HD-06菌株对马唐的致病性分析及初步鉴定     

邹德勇  杨智越  杜春梅 《植物保护》2020,46(4):98-104

为了得到能够有效抑制马唐Digitaria sanguinalis生长的生防微生物,在农田采集马唐种子,进行萌发试验,观察种子的萌发状况,从发病的种子和马唐幼苗基部分离致病菌,通过形态学观察以及ITS序列分析对致病菌进行鉴定。结果从罹病的马唐幼苗基部分离得到一株致病菌HD-06,该菌株的发酵液用水稀释至60%浓度时,对马唐种子的萌发抑制率和幼苗发病率均达到100%,这说明菌株HD-06对马唐有较好的生物防治作用。根据其形态学特点及ITS序列分析结果,鉴定菌株HD-06为暗球腔菌属Phaeosphaeria的真菌。这些结果为深入研究其对马唐的防治作用奠定了基础。  相似文献   

斑唇马先蒿挥发油的超临界萃取及GC-MS分析     

王劼  陈保业  晁玉龙  邓娟  孙菁  袁园园  周玉碧 《甘肃农业大学学报》2017,52(2)

【目的】探究斑唇马先蒿挥发油的最优超临界萃取条件及其化学组成.【方法】通过正交试验筛选斑唇马先蒿挥发油的最优萃取条件.将最优萃取条件下得到的挥发油,经柱色层族组成分离为非极性、弱极性和极性3种馏分,并进行了GC-MS分析.【结果】斑唇马先蒿挥发油最优萃取条件为:压力25 Mpa,温度45℃,CO2流量16mL/min.斑唇马先蒿挥发油中共鉴定出127种化合物,其中非极性馏分、弱极性馏分、极性馏分的主要组成成分分别为烷烃类、酯类和脂肪酸类.在其挥发油成分中,脂肪酸类化合物占绝对优势,总相对含量为62.698%;其中亚麻酸(18.497%)的相对含量最高,其次为正十六烷酸(15.698%)和亚油酸(7.286%).【结论】本研究获得的斑唇马先蒿挥发油的最优萃取条件温和,效率高,其挥发油的化学成分种类丰富.  相似文献   

UV-B radiation increases paraquat tolerance of two broad-leaved and two grass weeds in relation to changes in herbicide absorption and photosynthesis   总被引：1，自引：0，他引：1  

S WANG  L DUAN  J LI  X TIAN  & Z LI 《Weed Research》2007,47(2):122-128

Depletion of the protective ozone layer in the atmosphere leads to increasing UV‐B radiation on the earth's surface with potential effects on the response of plants to different stresses. Abutilon theophrasti, Amaranthus retroflexus, Digitaria sanguinalis and Chloris virgata are common weeds encountered in most arable fields in China. The effectiveness of herbicides used in controlling these weeds needs to be evaluated with increased UV‐B radiation. Seedlings of these four weeds were therefore grown under ambient and elevated UV‐B radiation to compare the efficacy of paraquat, a commonly used contact herbicide. Irrespective of species sensitivity to radiation, the elevated UV‐B radiation decreased the effectiveness of paraquat. Net photosynthesis rate was adversely affected except for D. sanguinalis, while the chlorophyll content was significantly reduced in A. retroflexus and C. virgata. UV‐B treatment increased the leaf surface wax and decreased the absorption of ¹⁴C‐paraquat in A. theophrasti, D. sanguinalis and C. virgata. These results suggest that the response of weeds to paraquat or the use of the herbicide may be affected by increased UV‐B radiation, to the extent that larger doses may be required to achieve desired effects. This may have damaging consequences for the environment.  相似文献   

马唐牧草红壤氮肥的氨挥发、径流和淋溶损失     

周静  崔键  胡锋  王国强  马友华 《土壤学报》2007,44(6):1076-1082

探讨了我国南方红壤上种植牧草马唐施不同量氮肥,施氮量与土壤氨挥发、径流和1 m深土壤淋溶损失氮量的关系。结果表明,在施用N 90、160、230 kg hm-2尿素处理下,土壤氨挥发损失量分别为N0.67、1.24和5.16 kg hm-2,分别占施氮量的0.74%0、.77%和2.24%,土壤氨挥发损失量(y)与施氮量(x)呈指数递增关系:y=0.156 3e0.014 6x;径流氮素损失量分别为N 1.05、0.88和1.01 kg hm-2,分别占施氮量的1.17%、0.55%和0.44%,径流损失的氮量与施氮量之间无明显相关性;淋溶损失总氮量为2.05、2.86和4.09kg hm-2,分别占施氮量的0.91%、1.02%和1.24%,土壤淋溶损失总氮量(y)与施氮量(x)呈线性递增关系:y=0.012 2x 1.087 7。  相似文献   

施肥和种间竞争对黄顶菊入侵土壤微生物的影响     

郭艾英  杨晴  陈凤新  叶红  张风娟 《植物保护》2015,41(3):54-59

田间条件下建立了入侵植物黄顶菊(Flaveria bidentis)和伴生草本植物马唐(Digitaria sanguinalis)、益母草(Leonurus japonicus)单独种植(以下简称单种)和混合种植(以下简称混种,比例1∶1)小区,设置施氮肥和不施氮肥处理,研究两者对黄顶菊入侵土壤微生物的影响。结果表明:黄顶菊单种小区,土壤增施氮肥黄顶菊的生物量显著升高,且促进了真菌的生长,抑制放线菌、有机磷细菌和钾细菌的生长。黄顶菊与马唐竞争生长,施肥显著抑制了放线菌、有机磷细菌和钾细菌的生长,黄顶菊的竞争攻击力系数(aggressivity,以下简称AG)小于0,在竞争中黄顶菊不占优势;不施肥时细菌、放线菌、有机磷细菌的数量与黄顶菊生物量显著正相关(P0.05),且AG0,在竞争中黄顶菊占优势。黄顶菊与益母草竞争生长,施肥与否仅有机磷细菌数量显著高于裸土,且微生物数量与黄顶菊生物量都无显著相关性(P0.05),黄顶菊的AG都小于0,在竞争中不占优势。由此,黄顶菊与马唐或益母草竞争生长,增施氮肥改变了土壤微生物数量,降低了黄顶菊的种间竞争能力,不利于实现黄顶菊的入侵。  相似文献   

Survey and examination of the potential alternative hosts of Villosiclava virens,the pathogen of rice false smut,in China          下载免费PDF全文

DENG Qi-de  YONG Ming-li  LI Dan-yang  LAI Chao-hui  CHEN Hong-ming  FAN Jing  HU Dong-wei 《农业科学学报》2015,14(7):1332-1337

Rice false smut is caused by ascomycete Villosiclava virens, whose potential alternative hosts have been assumed previously. Here its potential alternative hosts were surveyed and identified from 2008 to 2013 in the main rice-growing regions in China. Two common weeds in paddy fields, Digitaria sanguinalis Scop. and Echinochloa crusgalli(L.) Beauv., were found to present the similar symptoms to smut diseases in a few individuals in 2012 and 2013 in Zhejiang and Sichuan provinces of China, respectively. After the examinations of the spore morphology, their infection and extension mode in hosts, pathogen cell wall components, and molecular identification, the two pathogens were identified to be the Basidiomycetes, Ustilago syntherismae and Ustilago trichophora, respectively. So far there has been no alternative host of V. virens to be identified in China. These suggest that the alternative hosts of V. virens, if they do exist, are not possible to play an important role in the pathogen life cycle and the disease epidemics.  相似文献   

Roles of emergence time and interspecific competition on the dominance and coexistence of Setaria faberi and Digitaria ciliaris in an orchard weed community in Japan     

Matsuo Itoh  Robert J. Froud‐Williams 《Weed Biology and Management》2014,14(1):31-42

Setaria faberi and Digitaria ciliaris are summer annual grass weeds that constitute an orchard weed community in Japan. Species dominance in the weed community shifts from S. faberi to D. ciliaris with an emergence delay. The change in species dominance is assumed to be a clue to how weeds dominate or coexist in shaping the community. Population dynamics and seasonal variations in emergence and competitive ability were studied from this viewpoint. Field monitoring and pot experiments exhibited that the emergence period of the two species overlapped extensively from April to June. The emergence of S. faberi began 2 weeks earlier than that of D. ciliaris in April and declined in June as a result of the induction of secondary dormancy. The plant density of D. ciliaris was high during the whole period. The great mortality of the species was replenished with its great natality. The replacement series experiments revealed that S. faberi that had been planted in April was a better competitor than D. ciliaris, but it lost its competitive superiority in the June plantings, when D. ciliaris became a superior competitor to S. faberi. The level of seed output was greater for D. ciliaris, even when it was an inferior competitor. Therefore, the shift in species dominance appeared to be attributed to a change in competitive superiority between the two species. The early emergence of S. faberi and the high plant density of D. ciliaris might accelerate competitive exclusion. The two species coexist when they are equivalent in competitiveness.  相似文献   

马唐生防菌厚垣孢镰刀菌ZC201301的生物学特性研究   总被引：1，自引：0，他引：1  

李健  李岩  高兴祥  房锋  李美 《草业学报》2016,25(3):234-239

厚垣孢镰刀菌ZC201301对杂草马唐具有良好的生物防效,本研究通过单次单因子法对菌株ZC201301的基本生物学特性进行了进一步研究.结果表明,菌株ZC201301最适生长培养基为PDA和CAJ培养基,最适生长温度为25~30℃,最适生长pH值为6~8;菌株ZC201301在多种培养基上均能产孢,最适产孢培养基为马唐汁液培养基,日光灯照射对菌丝生长影响不显著,但是对产孢有一定抑制作用;菌丝生长最佳碳源为葡萄糖,最佳氮源为硝酸铵;菌落生长需要充足氧气,气/液小于1:1时菌丝生长受到抑制.湿度是影响ZC201301发挥生防效果的重要因子,环境湿度小于60%时生防效果下降显著.以上结果说明,该菌适宜培养,这对于其生防菌剂的制备及在田间条件下存活有重要意义.  相似文献   

几种除草剂防除棉田杂草马唐试验   总被引：2，自引：2，他引：0  

朱文达  崔海芝  何燕红  李林  唐海燕  张庆平 《湖北农业科学》2008,47(10)

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.  相似文献