Reflectance-based assessment of spider mite “bio-response” to maize leaves and plant potassium content in different irrigation regimes     

《Computers and Electronics in Agriculture》2013

It is widely accepted that pest infestations elicit a change in plant physiology, which cause detectable changes in crop leaf reflectance. In this study, we test the hypothesis that crop leaf reflectance may also be used to forecast the risk of pest infestation before they actually occur. We collected reflectance data in 160 spectral bands from 405 to 907 nm from excised leaf pieces from field grown maize plants under 3 irrigation regimes. Leaf material was collected at weekly intervals in two growing seasons. The same leaf pieces were used in choice bioassays with carmine spider mites to assess attractiveness to mites (spider mite “bio-response”) across irrigation regimes. In one growing season, we also obtained nutritional element data (lipid, protein, soluble sugar, starch, lignin, Ca, P, Mg, K, S, and Cl) from whole maize plants. Principal component analysis showed that potassium content (K) was highly negatively correlated with spider mite bio-response. Relative reflectance at 740 nm showed a highly significant and positive trend across spider mite bio-response classes, and that potassium content showed a highly significant and negative trend across the same classes. Thus, we argue that relative reflectance at 740 nm may be used to predict both potassium content and risk of spider mite infestation. Based on extensive reviews, potassium leaf content is known to reduce susceptibility of crops to pests. The results presented provide encouraging support for remotely sensed risk assessment of pest infestations through reflectance-based monitoring of maize leaf attractiveness and highlight that reflectance based monitoring of crop susceptibility may be possible through careful management of macro element crop properties, such as potassium content.  相似文献   

A hundred and more years of plant protection in the Netherlands     

J. C. Zadoks 《European journal of plant pathology / European Foundation for Plant Pathology》1991,97(1):3-24

At the occasion of the Centenary of the Netherlands Society of Plant Pathology a reflection on past, present and future of plant protection, the subject matter of the Society, was thought to be appropriate.Developments in plant protection are projected against a general stream of thought. Three turning points are distinguished which can be seen as paradigm changes. The first occurred around 1890, when the concept of pathogenitism gained its final victory over autogenitism. The second occurred around 1940, when the public outlook on human and plant health changed drastically due to the advent of chemotherapeutants. The third occurred around 1990 when a clear change in public thinking on agriculture, environment and plant protection became apparent. The background of these changes is sketched in a personal manner.Some ideas on plant protection beyond the year 2000 are given, based upon recent developments in the Netherlands to which the Society contributed in its own way.  相似文献   

绿洲农业作物生态─—经济优势分析及布局调整     

刘卫东  刘景辉  李春林 《干旱区资源与环境》1995,(4)

本文以临河市绿洲农业为例，通过建立高产效益、生物量、等价产量、稳产性能、增产性能、综合性能、产值、光能利用率、热生产效率的隶属函数关系，用Ｆｕｚｚｙ向量Ａ和Ｆｕｚｚｙ矩阵Ｒ根据Ｂ＝Ａ·Ｒ的关系，首次分析了临河市绿洲农业粮经作物的生态经济优势。由此确定调整农作物结构数学比例关系，并结合生产实际提出了粮经作物的调整方案，为绿洲农业建设的作物初级生产力调控提供理论依据。  相似文献   

Soil tillage for crop production and for protection of soil and environmental quality: a Scandinavian viewpoint     

Inge H  kansson 《Soil & Tillage Research》1994,30(2-4):109-124

Based on experience from 35 years of tillage research in Sweden, future development of soil tillage is discussed and some research problems are identified. Tillage and seeding methods must be more carefully adapted to conditions at individual sites and occasions. Low-pressure typres, better weed control and improved seed coulters favour the increased use of reduced tillage. In order to diminish the impact of agriculture on the environment, it is necessary to develop methods for establishment of crops in the early spring or immediately after harvest, even in soils with large amounts of crop residues or high moisture content. The roles of tillage methods, and of soil compaction and structure on environmental impact of agriculture must be investigated. World food production must increase, since the world population is rapidly increasing. Therefore, it is necessary to develop improved crop production systems, including crop establishment systems, which favour efficient use of basic crop growth factors, while protecting or increasing soil productivity. Compaction, decreased organic matter content, and erosion are important long-term threats to soil productivity.  相似文献   

中国作物种质资源收集保存评价和利用成果研究回顾与展望     

方嘉禾 《中国农业科学》2007,40(Z1):2979-2987

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基于知识模型的作物适应性评价专家系统设计     

陈长青  周治国  曹卫星 《勤云标准版测试》2004,(6)

系统引入了知识模型概念,建立了以知识模型为特征的知识系统,将知识工程、数据库有机结合,采用正向与反向相结合的推理控制策略,建立了基于知识模型的作物适应性评价专家系统,实现了作物适应性评价的计算机辅助决策,具有较强的跟踪解释能力。用本系统对江苏省地区小麦适应性还进行了实例分析。  相似文献   

Impacts of urbanization on topsoil nutrient balances—a case study at a provincial scale from Fujian,China     

Wenzhi Cao  Hejian Zhu  Songlin Chen 《CATENA》2007

With increasing urbanization, the demands for high quality agricultural products induced changes in local cropping patterns. Although grain production still occupied a large portion in sown and planted areas, the share of sown areas declined from 67% to 44% for total grain crops, and 54% to 35% for rice between 1989 and 2002 in Fujian province. The change in crop spectrum and land use by urbanization has resulted in two extreme trends in topsoil — nutrient depletion in grain-dominated regions and nutrient overload in city suburbs. The positive correlation between nitrogen balance and local urban population in some years showed that urbanization affected nutrient balance in topsoil. The rapid changes in land use and crop spectrum caused by urbanization therefore created a challenge to the traditional soil nutrient management derived mainly from paddy fields and an urgent need for new management schemes in the province. The study provides valuable insights into nutrient management and soil sustainability in the context of rapid urbanization and population growth in Fujian.  相似文献   

Weed control and sesame (Sesamum indicum L.) response to preplant incorporated herbicides and method of incorporation     

W. James Grichar  Peter A. Dotray 《Crop Protection》2007,26(12):1826-1830

Field studies were conducted at two sesame-growing regions of Texas in 2004 and 2005 to determine weed control and sesame response to four dinitroaniline herbicides and their method of incorporation. Ethalfluralin, pendimethalin (formulated as Prowl EC), and trifluralin were applied at the X, 1X, and 2X of the suggested label dose for Gossypium hirsutum L. Pendimethalin (formulated as Prowl H₂O) was applied at the X, 1X, and 1X rate. Two methods of incorporation included rolling cultivator mixing wheels and spring tooth harrow. With rolling cultivator mixing wheels, all herbicides controlled Amaranthus tuberculatus (Moq.) J.D. Sauer at least 74% regardless of dose. The X dose of ethalfluralin and pendimethalin (formulated as Prowl EC), or the X and 1X dose of pendimethalin (formulated as Prowl H₂O) controlled Brachiaria platyphylla (Griseb.) Nash no better than 73% while all other doses of the herbicides controlled B. platyphylla at least 80%. The use of mixing wheels to incorporate the herbicides resulted in better sesame stands and less stunting than the use of the spring tooth harrow; however, sesame stands were reduced as herbicide rate increased when using mixing wheels. Ethalfluralin at the 1X dose, pendimethalin (formulated as Prowl H₂O) at the X dose, and trifluralin at the X dose produced the highest sesame yield while ethalfluralin at the 2X dose produced the lowest yield.  相似文献   

作物模型应用与遥感信息集成技术研究进展     

彭慧文  赵俊芳  谢鸿飞  房世波 《中国农业气象》2022,43(8):644

作物模型和遥感技术以各自独有的优势在作物生产监测、评估及未来预测等方面发挥着关键作用。作物模型与遥感信息集成技术在大尺度、高精准的农业生产监测、评估与预测上具有明显的应用优势和广阔的发展前景。为了促进这些技术在区域尺度上的作物产量预测、农业气象灾害影响评估及农业应对气候变化决策等方面更加广泛地应用,本文采用文献综述的方法,系统归纳了欧洲、美国、澳大利亚及中国作物模型的发展与应用,总结了当前主流的数据集成方法的原理、特点和不足,概述了作物模型与遥感信息集成技术的实际应用,探讨了提升数据集成精度存在的问题,并对未来研究方向进行展望。结果表明,国内外对于作物模型及其与遥感数据集成的研究与应用广泛而深入,利用同化方法能够有效提高作物模型模拟精度,为作物模型实现区域尺度作物生长及产量评估、气候变化对产量影响、农田管理决策等提供技术支撑。作物模型模拟结果及遥感反演数据的不确定性、数据同化策略的多样性以及尺度效应是进一步提高集成系统精度与效率的限制因素。因此,遥感数据多源融合、同化过程多变量协同、作物模型多类型耦合以及数据高性能并行计算是未来作物模型与遥感数据集成研究的发展趋势。  相似文献   

临时性水土保持技术应用于农作物保护的探讨     

李明宝  于司杭  阎梦请  郑宪 《安徽农业科学》2014,(34):12232-12234

公路工程建设的不断增多导致公路周边的水土流失问题严重,并将影响到公路旁的农作物生长.针对水土流失这一问题,提出全新的工程措施进行防治,从而达到保护水土,防止农作物被破坏的目的.  相似文献