Thiocarbamate fungicides: reliable tools in resistance management and future outlook

Among contact fungicides, dithiocarbamates have remained successful and are used worldwide. These organic sulfur fungicides, viz. mancozeb, maneb, zineb, ziram, thiram, metiram and propineb, have helped growers manage several economically important plant diseases. Their multi‐site mode of action and broad‐spectrum disease control make them some of the most common partners in mixtures of a number of single‐site fungicides as part of resistance management strategies. Indeed, it was the part played by ethylene‐bis‐dithiocarbamates such as mancozeb in delaying the evolution of phenylamide resistance in several oomycete phytopathogens that laid the groundwork for mixture strategies to become a cornerstone of anti‐resistance management in plant disease control. Dithiocarbamates, however, do not have systemic action, are only surface protectants and have to be applied prior to pathogen infection. Dithiocarbamates will likely continue play a key role as reliable resistance management tools to prolong the efficacy of single‐site fungicides. The primary metabolite ethylene thiourea produced by some of these fungicides is considered a reproductive and endocrine disrupter in animals. Therefore, dithiocarbamates need to be used at reduced rates or in slow‐release formulations. © 2017 Society of Chemical Industry     

联合施用不同植物物质和鸡粪对土壤碳氮含量和蔬菜产量的影响

The use of plant materials as soil amendments is an uncommon practice amongst major farming communities in Ghana, although it is necessary for soil fertility improvement. An examination of the effects of soil amendments is necessary to encourage the use of under-utilized organic resources in Ghana. Thus, a field experiment was conducted using 8 different tropical plant materials mixed with chicken manure as soil amendments for growth of tomato as a test crop. The plant materials included Leucaena leucocephala, Centrosema pubescens, Sesbania sesban, Gliricidia sepium, Mucuna pruriens, Pueraria phaseoloides, Azadirachta indica, and Theobroma cacao. There were two other treatments: one with equivalent amounts of chemical fertilizers and the other with no-fertilizer input (control). Plant materials were mixed with chicken manure to obtain a uniform carbon-to-nitrogen (C:N) ratio of 5:1. Except the no-fertilizer control, all treatments received the same amount of nitrogen (N). To clarify the decomposition pattern of the plant materials in soil, an incubation experiment was conducted using only the plant materials before the field experiment. The Gliricidia treatment released significantly more mineral N than the other plant materials in the incubation experiment. However, the tomato fruit yield was not enhanced in the Gliricidia treatment in the field experiment. The known quality parameters of the tested plant materials, such as total N, total carbon (C), C:N ratio, and total polyphenols, had minimal effects on their mineralization dynamics. Azadirachta showed the best synergistic effect with chicken manure through significantly increasing soil microbial biomass and fruit yield of tomato. This result provides insights into the possible adoption of Azadirachta in combination with chicken manure as a soil amendment in small-scale agricultural holdings.     

全玻璃真空管太阳能集热器对流换热试验与模拟

以可再生能源总能系统为研究背景,通过搭建太阳能辅助燃料电池试验平台,逐步完成不同涂层材料、内置导流板太阳能集热器自然对流试验研究;在试验验证基础上,分别建立太阳能集热器自然对流和强迫对流三维数学模型,应用场协同和火积理论分析流动和传热数据。自然对流研究表明,吸收率在0.95~1.0、发射率在0.06~0.16时,随吸收率升高,发射率降低,热效率升高1.71%,火积增量逐渐增大;加装导流板后,真空管内部混流消失,底部流动得到强化,实验热效率提高2.17%;确定全玻璃真空管热水器导流板合理板厚为2 mm,合理板长为距离真空管底部60~100 mm,合理位置为中心线以上16~20 mm;强迫对流研究表明,横双排集热器雷诺和努赛尔数、火积增量均高于竖单排集热器,火积耗散低于竖单排集热器。确定太阳能辅助燃料电池集热场在中低温条件下,自然对流采用内置导流板集热器,强迫对流采用横双排集热器。     

都市郊区乡村景观多功能权衡-协同关系演变

针对景观功能相互表征的科学性和景观多功能间关系定量化问题,采用Spearman秩次相关系数分析和双变量空间自相关相方法,对上海市青浦区184个行政村1980-2015年的乡村景观多功能间权衡-协同关系变化特征进行研究,结果表明:1)农业生产功能不能取代经济发展功能,青浦区经济发展功能已成为主导的功能形态。2)该区乡村景观多功能间权衡-协同关系时空差异显著,表现为:生产功能-生活功能以协同为主,空间上沿中轴线扩散;生产功能-生态功能以权衡为主,空间上从中部向东部扩散;生活功能-生态功能权衡-协同关系较为均衡,权衡区由中部向东部扩散,协同区由西部向北部和南部扩散。农业生产功能与经济发展功能、经济发展功能与生态调节功能/环境维衡功能为该区不可回避的矛盾;经济发展功能与景观美学功能间权衡关系显著,且两者关系格局呈东部权衡西部协同,且权衡区的数量递增;经济发展功能与空间承载功能呈现东部权衡和西部协同,且协同区呈增长趋势;景观美学功能与生态调节功能/环境维衡功能间权衡区集中在青东区域,协同区分布于青西区域,且权衡区数量先增后减,协同区先减后增。3)时空结合的分析方法能准确全面的反映乡村景观多功能间权衡-协同关系演变特征。     

林业推广服务与技术应用的效率及协同度研究

为探索制约林业科技成果转化的关键因素,了解当前林业推广现状、特征和存在的问题,结合二阶段DEA-HR模型和GIS对28个省(市、区)的林业推广效率及其参与主体的协调情况进行测算,分析林业推广服务效率与林业技术应用效率的时空变化,针对其协调情况进行了类别划分和评价。结果表明,林业推广服务效率为0.328～0.573,其中纯技术效率偏低;林业技术应用效率值在0.622以上,其中规模效率偏低。林业推广服务的高效率地区数量由7个增加到10个,林业技术应用的高效率地区数量由17个增加到2015年的25个。"协调且有效"的区域有13个,"协调且无效"的区域有3个,"不协调且有效"的区域有6个,"不协调且无效"的区域有6个。研究表明,林业推广服务效率低于林业技术应用效率,纯技术效率是制约林业推广服务效率的重要因素,规模效率是制约林业技术应用效率的重要因素;林业推广服务与林业技术应用两阶段效率在空间分布格局上呈现不同的变化,但高效率地区的数量均有所增加,呈现良好的发展态势;林业推广参与主体的协调类别呈现不同的分布特征,且不协调的原因各异,其中"协调且有效"的区域偏多,且分布呈集聚效应。     

基于金融协同发展的安徽省战略性新兴产业绩效研究

基于安徽省2000—2015年时间序列数据利用DEA模型对安徽省战略性新兴产业绩效进行分析,以协同度模型分析区域金融发展水平与战略性新兴产业复合系统协同度,以二者复合协同度作为自变量,对战略性新兴产业绩效进行回归分析。研究发现：安徽省战略性新兴产业整体绩效呈波动状态,资金综合运用效率不高;金融子系统与战略性新兴产业子系统有序度均呈明显上升趋势,但二者复合系统协同度不高;区域金融发展水平与战略性产业复合系统协同度对战略性新兴产业绩效有显著的正向影响。     

基于高时空分辨率遥感数据协同的作物种植结构调查

[目的]充分发掘遥感影像的空间、时间和光谱等特征谱信息,探索地块基元支持下的多源遥感数据作物种植信息自动识别方法,为作物种植结构信息的快速、精细化调查提供借鉴.[方法]以广西扶绥县为研究区,通过对高空间分辨率影像的多尺度分割和对象廓线编辑,提取精细农田地块信息;以地块为基元获取覆盖作物生育期内的时序光谱特征;基于时序光谱及其变化定义与作物长势状况相关的描述参量,形成静态光谱与动态过程特征结合的多维特征空间,结合作物的物候节律特征构建作物种植信息提取模型,实现主要农作物种植结构信息的提取.[结果]依据上述方法绘制出广西扶绥县甘蔗、水稻和其他作物农田及草地、林地、水体、城镇建设用地等的精细地块图,其中,提取广西扶绥县甘蔗和水稻作物的总面积分别为82420.01和6806.67 ha,作物提取的总体分类精度为86.8%,Kappa系数为0.84.[结论]提取的广西扶绥县作物种植结构的成果满足使用精度要求,可为精准农业补贴投放、农业灾害定损等政策制定提供依据,而技术方法对于作物种植结构信息的快速、精细化调查具有借鉴意义.     

协同创新：农业高校提升人才整体效能的新路径

在当今这个注重整体开发人才、团队协作攻坚的时代,高校应更致力于提升人才的整体效能.但农业高校在实践中遭遇了困境,校内合作意识不强、学科壁垒森严;校外缺乏合作愿景、行业条块分割.协同创新是农业高校提升人才整体效能的新路径.农业高校要把握好社会需要整体开发人才和国家实施高校协同创新战略的现实良机,积极开展校内和校外的协同创新,让协同的团队建构共同愿景,乐于协同;并且在健全的协同机制的保障下,有效地进行协同,从而提升人才的整体效能.     

黏细菌活性代谢产物的互动筛选

【目的】研究互动筛选在黏细菌活性代谢产物筛选中的效果,以期为有效地获得高效、低毒的黏细菌活性产物提供支持。【方法】在构建互动筛选抗真菌模型的基础上,对分离自陕西秦巴山区的黏细菌代谢产物进行互动筛选和非互动筛选,比较代谢产物初筛、复筛后的阳性率,并对筛选结果进行验证,最后对筛选的黏细菌阳性菌株的16SrDNA序列进行比对和同源性分析。【结果】利用互动筛选模型经初筛和复筛分别获得阳性产物25和19个,阳性率分别为2.23%和1.69%;而非互动筛选模型经初筛和复筛获得的阳性产物分别为20和4个,阳性率分别为1.78%和0.36%。互动筛选试验的重现性为100%,而非互动筛选试验的重观性为50%。对互动筛选出的19个代谢产物的15株黏细菌来源菌株进行鉴定发现,菌株83的16SrDNA序列与亲缘关系最近的Myxococcus virescens strain DSM 494的同源性仅为96%,可能为新菌种。【结论】互动筛选方法能够有效提高黏细菌活性产物筛选的阳性率,且重现性好。本研究所分离菌株83可能为1种新菌种,有望从中发现新的活性产物。