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1.
Proximal remote sensing is being widely studied as a noninvasive method to partially automate diagnostics of plants and insects. The hypothesis that proximal remote sensing can be used to differentiate specimens of adult beet leafhoppers (Circulifer tenellus) that were nonviruliferous or viruliferous for beet curly top virus (BCTV) was tested. A key aspect of applications of proximal remote sensing is the ‘robustness’ or repeatability of input reflectance data. Many factors may contribute to low input reflectance data robustness; these include: (i) issues related to the consistency of proximal remote sensing conditions (light intensity and spectral composition, ambient temperature), (ii) insect specimen preparation (projection angle, storage and handling), and (iii) insect specimen characteristics (age, growing conditions, variety/biotype, host plant). This study demonstrates that nonviruliferous and viruliferous specimens of adult beet leafhoppers possess unique body reflectance features and, therefore, can be differentiated. However, insect specimen preparation (removal of wings and placement) markedly affected the classification accuracy. Addition of experimental noise to input reflectance data was conducted to simulate varying degrees of input reflectance data robustness. The potential of developing reflectance-based diagnostic tools for detection of plant pathogenic viruses in insects is discussed, with an emphasis on input data robustness.  相似文献   

2.
植物发生病虫害时,叶绿素水平会出现不同程度的下降,这种下降通常表现为近红外波段的反射率下降,在近红外遥感图像上可以探测到这种变化。通过一元回归分析证实了虫害水平与植物近红外影像色调具有显著相关性,研究了反射率测定及相关分析中采样位置与植物病虫害水平信息的关系,并对区分虫害类型是否有助于提高相关性等进行了比较研究。最后通过给出描述虫害水平与植物近红外影像色调关系的定量表达式和开发出相应的采样分析软件,使遥感技术大面积、快速监测城市绿化植物虫情成为可能。  相似文献   

3.
近年来, 随着计算机、互联网、物联网、人工智能、传感器、遥感等技术的快速发展, 智能虫情测报灯、智能性诱捕器、昆虫雷达、无人机遥感、卫星遥感、智能识别App等现代智能农作物病虫监测装备及重大病虫害实时智能监测预警系统建设方面取得了比较明显的进步。本文综述了我国近5年在利用光谱遥感、昆虫雷达、图像识别等技术进行农作物病虫害监测预警研究和应用方面取得的重要进展, 分析了各类技术存在的不足与难点, 提出了未来发展的方向, 以期为充分利用空天地多源数据实现农作物病虫害精准预报提供指导。  相似文献   

4.
害虫遗传学控制策略与进展   总被引:1,自引:1,他引:0  
随着分子生物学和基因工程技术的发展,利用遗传学方法控制害虫种群成为人们研究的热点之一。研究者已经尝试利用基因突变、转基因和雄性不育等遗传学技术,培育遗传改造的害虫品系,释放后来控制自然界害虫的种群密度。但由于这些遗传学方法本身存在局限性,研究者开始探索利用低毒高效的荧光纳米材料基因载体携带外源核酸或农药分子进入昆虫或植物细胞从而干扰害虫的发育或行为的新策略。本文综述了害虫遗传学控制的2大策略种群替代和种群抑制的实现方法及其研究进展,并提出了利用新型荧光纳米粒子传送基因或药物的害虫遗传学控制新策略。  相似文献   

5.
本文回顾了利用极轨气象卫星遥感资料进行草地估产的研究工作成果 ,自80年代开展研究以来 ,已实现了 RS- GIS- GPS的结合与自动化、系统化、业务化的目标。介绍了应用极轨气象卫星进行草地遥感估产的原理与方法 ,并以内蒙古锡林郭勒盟乌拉盖地区与东乌珠穆沁旗为例 ,探讨了草地生产力的有关问题。确定了乌拉盖地区的北纬 4 6度以北是植被指数最高的草地区域 ,生产力较高 ,北纬 4 6度以南植被指数与生产力较低。  相似文献   

6.
A research summary is presented that emphasizes ARS achievements in application technology over the past 2-3 years. Research focused on the improvement of agricultural pesticide application is important from the standpoint of crop protection as well as environmental safety. Application technology research is being actively pursued within the ARS, with a primary focus on application system development, drift management, efficacy enhancement and remote sensing. Research on application systems has included sensor-controlled hooded sprayers, new approaches to direct chemical injection, and aerial electrostatic sprayers. For aerial application, great improvements in on-board flow controllers permit accurate field application of chemicals. Aircraft parameters such as boom position and spray release height are being altered to determine their effect on drift. Other drift management research has focused on testing of low-drift nozzles, evaluation of pulsed spray technologies and evaluation of drift control adjuvants. Research on the use of air curtain sprayers in orchards, air-assist sprayers for row crops and vegetables, and air deflectors on aircraft has documented improvements in application efficacy. Research has shown that the fate of applied chemicals is influenced by soil properties, and this has implications for herbicide efficacy and dissipation in the environment. Remote sensing systems are being used to target areas in the field where pests are present so that spray can be directed to only those areas. Soil and crop conditions influence propensity for weeds and insects to proliferate in any given field area. Research has indicated distinct field patterns favorable for weed growth and insect concentration, which can provide further assistance for targeted spraying.  相似文献   

7.
国内外蝗虫研究发展动向初探   总被引:14,自引:1,他引:14  
蝗虫是广泛分布于世界各地尤其是中低纬度地区的一种昆虫,其分布广泛性和危害严重性使之成为多门学科重要的研究对象之一。本文比较系统地总结了当前国内外蝗虫研究状况和近新进展,初步探讨了蝗虫研究中的若干新领域与新技术,对开展相关研究有一定的借鉴意义。  相似文献   

8.
利用遥感指数反演土壤水分已成为监测干旱的重要手段之一,而单一的遥感干旱指数对于反演土壤水分存在一定局限,本研究从7种不同MODIS遥感干旱监测指数中选取适宜的5种并结合径向基函数神经网络(RBFNN)协同反演江苏省2018年冬小麦需水关键期的土壤相对湿度。结果表明:与单一的遥感干旱指数相比,协同RBFNN的遥感干旱指数反演的模型效果更好,与10 cm和20 cm深度的实测土壤相对湿度的相关系数分别达到0.5161和0.4307,能综合多种通道的遥感信息反映当地土壤水分的变化;同时研究利用RBFNN对2017年5月江苏冬小麦10 cm深度土壤相对湿度进行反演,得到的土壤相对湿度分布图与实测土壤墒情结果较为接近,说明利用RBFNN反演模型有效。研究结果提高了土壤湿度的反演精度,为当地农业干旱的实时监测提供了新思路。  相似文献   

9.
During 1999-2001, ARS scientists published over 100 papers on more than 30 species of insect pest and 60 species of predator and parasitoid. These papers address issues crucial to the three strategies of biological control: conservation, augmentation and introduction. Conservation biological control includes both conserving extant populations of natural enemies by using relatively non-toxic pesticides and increasing the abundance of natural enemies in crops by providing or improving refuges for population growth and dispersal into crops. ARS scientists have been very active in determining the effects of pesticides on beneficial arthropods and in studying movement of natural enemies from refuges into crops. Augmentation involves repeated releases of natural enemies in the field, which can be inoculative or inundative. Inoculative releases are used to initiate self-propagating populations at times or in places where they would be slow to colonize. ARS scientists have studied augmentative biological control of a variety of pest insects. The targets are mostly pests in annual crops or other ephemeral habitats, where self-reproducing populations of natural enemies are not sufficiently abundant early enough to keep pest populations in check. ARS research in augmentative biological control centers on methods for rearing large numbers of healthy, effective natural enemies and for releasing them where and when they are needed at a cost less than the value of the reduction in damage to the crop. ARS scientists have researched various aspects of introductions of exotic biological control agents against a diversity of pest insects. The major issues in biological control introductions are accurate identification and adequate systematics of both natural enemies and target pests, exploration for natural enemies, predicting the success of candidates for introduction and the likelihood of non-target impacts, quarantine and rearing methods, and post-introduction evaluation of establishment, control and non-target impacts. ARS scientists have published research on several general issues in biological control. Among the most important are the mechanisms affecting mate- and host-finding and host specificity.  相似文献   

10.
The development of detection of insect infestations from aircraft was reviewed. It started with visual observation and written records, and developed to photographic recording with color films and infrared films, then to enhancement of photographic images. Aerial photography was used to detect simulated insect defoliation in corn fields. Several guide-lines were established: defoliation on top of plant was easily detected while that on the base of plant was less so; aero infrared film with a Wratten 89B filter gave the best results, morning flight at the scale of 1: 15,840 is to be recommended, and row direction, plant growth stage and time elapse since defoliation were not important factors. The multiple uses of aerial photography in agricultural monitoring were proposed, and the research needed to implement the proposed scheme was outlined. The potential and limitations of remote sensing from spacecraft such as the Earth Resources Technology Satellite and the SKYLAB were discussed.  相似文献   

11.
多源遥感数据融合及其在土地资源调查中的应用   总被引:3,自引:0,他引:3  
多源信息融合的目的就是要充分集成不同来源数据的优点,尽可能多地获取地物信息,以大大提高解译精度和可信度。本文结合国土资源部“典型县耕地资源分布与生态退耕遥感监测”规划的前期预研究项目,利用ETM和SPOT等多源遥感数据,探讨不同遥感信息融合过程中的处理方法与关键技术,在对比分析所使用的各种数据优缺点的基础上,阐述了数据纠正、配准、融合的技术过程和出现的问题,列出本项目为遥感影像解译所归纳的主要地类的特征图谱。利用高分辨率遥感数据融合较低分辨率数据,进行土地利用变化分析,及时准确获取变化信息,为有关部门进行土地的规划、管理提供科学依据就有着十分重要的意义。  相似文献   

12.
为了研究沙漠化地区地下水位的分布状况,利用MODIS卫星遥感数据,采用遥感一数学一模型学融合的研究方法,在实地考察沙漠化地区地下水位、土壤水分和其它辅助资料的基础上,通过土壤水分和地下水位的线性方程,提出了基于MODIS影像数据,在土壤中存在毛细管补给条件时,简便、有效地监测沙漠化地区地下水埋深的遥感模型,并在毛乌素沙漠化地区进行了实地验证。结果表明,该模型反演地下水位和实测地下水位之间的相关系数为0.868,误差较小,研究结果符合实际。认为在较大范围且地下水埋深不大于7 m的沙漠化地区,利用MODIS多波段遥感模型监测并评价地下水位分布是可行的。  相似文献   

13.
作物估产的遥感—数值模拟方法   总被引:17,自引:1,他引:17  
本文在分析遥感估产、数值模拟估产方法的基础上 ,提出了作物估产的新思路—即利用遥感与农业气象数值模拟技术相结合的办法来进行作物估产研究 ,供同行们商讨。  相似文献   

14.
15.
蝗虫灾害是人类历史上三大自然灾害之一,对农牧业、环境和经济构成严重威胁。我国是世界上遭受蝗灾最严重的国家之一,有关蝗虫学的研究有较长的历史。60年前,通过改治结合,我国控制了大规模的飞蝗Locusta migratoria蝗灾发生,取得了举世瞩目的成就。60年过去了,中国蝗虫学研究发生了翻天覆地的变化。该文主要综述了最近60年中国蝗虫学研究的发现与创新,展示蝗虫分类学、生态学、生殖与发育生物学、分子生物学、基因组学研究以及蝗虫控制技术研究等多个方面的成就。这些研究成果是世界昆虫学研究的重要组成部分。特别是近30年,我国科学家深入揭示蝗虫两型转变的遗传和表观遗传机制,在国际上产生了重要影响。飞蝗的综合生物学研究积累使飞蝗成为继果蝇之后又一个昆虫模式系统。更重要的是,我国科学家开发的真菌生物农药和群聚信息素可以作为重要的防治手段用于蝗灾的治理。  相似文献   

16.
黑河中游地区区域蒸散量的时间变化规律及其影响因素   总被引:3,自引:3,他引:0  
表面能量平衡系统是应用卫星对地观测的可见光、近红外和热红外波段资料,结合实测气象数据或大气模式输出数据,根据表面能量平衡原理估算不同尺度的地表大气湍流通量,从而估算地表相对蒸散的一种方法。本文将水文数据与遥感数据相结合,对张掖盆地1990-2004年间的区域蒸散量进行了估算,评价了区域蒸散的年际变化规律,并对其影响因素进行了分析。结果表明:张掖盆地的区域蒸散量呈逐年升高的趋势,这种增长趋势与黑河中游莺落峡、正义峡间的耗水量增加,张掖地区人口、GDP的增长及农田用地的增加有着良好的相关性。  相似文献   

17.
This multi-author paper reviews current work by USDA-ARS scientists in the field of chemical ecology. Work with pheromones, the discovery and development of the codling moth kairomone, studies on insect-plant interactions and chemically mediated tritrophic plant-insect interactions have led to practical methods for control of important insect pests.  相似文献   

18.
USDA-ARS scientists have made important contributions to the molecular genetic analysis of agriculturally important insects, and have been in the forefront of using this information for the development of new pest management strategies. Advances have been made in the identification and analysis of genetic systems involved in insect development, reproduction and behavior which enable the identification of new targets for control, as well as the development of highly specific insecticidal products. Other studies have been on the leading edge of developing gene transfer technology to better elucidate these biological processes though functional genomics and to develop new transgenic strains for biological control. Important contributions have also been made to the development and use of molecular markers and methodologies to identify and track insect populations. The use of molecular genetic technology and strategies will become increasingly important to pest management as genomic sequencing information becomes available from important pest insects, their targets and other associated organisms.  相似文献   

19.
抑咽侧体素 (ASTs) 是一类由昆虫脑神经细胞分泌,通过作用于咽侧体进而抑制保幼激素 (JH) 合成与释放的昆虫神经肽。因其具有调控昆虫生长、发育和生殖等生理过程的功能,被认为是一类潜在的害虫控制剂。本文在简介了昆虫神经肽在害虫防治中的应用基础上,综述了昆虫神经肽抑咽侧体素的发现、类别和功能,并结合本研究组的工作,重点介绍抑咽侧体素及其类似物的结构修饰和优化、活性构象及构效关系研究,同时也介绍了抑咽侧体素及其类似物的受体和作用机制研究进展。最后,展望了该领域的未来发展趋势,期望为新的生态友好型农药的研发提供一定的参考作用。  相似文献   

20.
本文用室内光谱分析法找出了苹果害螨为害等级与680nm/800nm这一比值光谱指数的定量关系,并证明这种害虫在为害苹果树时对树冠没有方位性选择。这种病虫害为害与光谱相关关系的研究结果可使为害等级鉴别客观化和定量化,并为病虫害的遥感监测提供了依据。  相似文献   

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