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河南栽培牧草害虫调查研究 总被引:4,自引:1,他引:4
经过3年的调查研究,初步查明河南栽培牧草害虫124种,分属9目36科。其中17种为河南新记录害虫。豆科牧草田间主要害虫数量构成因牧草种类不同呈现不同的次序性,部分害虫发生存在着明显的地理特征。本文首次报导河南主要牧草田中害虫群落构成及其地理差异以及主要害虫发生概况,并对当前栽培牧草害虫防治策略提出了讨论意见。 相似文献
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In the Netherlands the greenhouse sector is a major user of energy. It accounts for 7% of the total national energy use and for 79% of the total energy use in agriculture. In order to sustain this sector on the long term, it is important that its use of energy is lowered. One way of reducing energy use by horticultural producers is investing in energy-saving systems. The purpose of this paper is to provide a better understanding of the investment behavior of firm operators in the adoption of energy-saving systems. Research objectives of the paper are (1) to analyze factors underlying the decision to invest, (2) to explore factors underlying the optimal size of investments. Three investment theories were used to construct an empirical model of investment. Consequently, this model was estimated in a two-stage procedure to analyze the factors influencing the decision of farmers to invest and the level of investments. The paper ends with policy implications. 相似文献
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D. Shtienberg Y. Elad Ariela Niv Y. Nitzani B. Kirshner 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(8):753-763
The most serious symptom of Botrytis cinerea in tomatoes grown in greenhouses is stem rotting. Lesions on the stem may result from direct infection or from progression of the rot along infected leaves, until infection approaches the stem. In a set of experiments conducted in commercial greenhouses, an experimental greenhouse and growth chambers, the significance of the two types of stem infections was studied. In non-heated greenhouses most of the stem lesions originated from progression of the pathogen along infected petioles. The rate at which B. cinerea had progressed on infected petioles was 0.3–0.5 cm/day, an average of ca. 6 weeks was needed for a leaf infection to approach the stem. Application of Trichoderma harzianum T39 extended this time by 1–2 weeks and application of chemical fungicides by 3 weeks. Influence of the environment on the progression of B. cinerea along infected petioles was then determined. Within range of 5–30 °C, the higher the temperature, the more rapid was the rate of disease progression. The fungus progressed more rapidly on tomato petioles incubated at high vapour pressure deficit (VPD) rather than at low VPD. The source-sink relationship of the plant governed the rate of B. cinerea progression along the petioles as well: it was more rapid when the source was restricted (by shading) and slower when the sink was restricted (by removal of flowers and small fruits). The possibility that sanitation of infected leaflets would reduce the incidence of stem rotting was examined in two experiments. In plots not treated with a fungicide, the sanitation treatment substantially decreased the incidence of stem lesions and this treatment was as effective as weekly application of chemical fungicides. 相似文献
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摘要:森林生态型自然保护区是一些珍贵、稀有的动、植物的集中分布区,候鸟繁殖、越冬或迁徙的停息地,也是某些饲养动物和栽培植物野生近缘种的集中产地,具有典型性、代表性或特殊性且较完整自然生态系统。它的宗旨在于管理和保护局部生物界和自然生态环境,通过科学管理和合理利用,保证其生态功能的正常发挥,对于改善区域生态现状,促进经济社会可持续发展,具有重大而深远的意义。本文主要描述省级自然保护区管理和科研存在的问题及对策,以山东牟平?山省级自然保护区为例。 相似文献
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分析中国农业标准化生产现状,发现其中存在的问题,提出与农业信息技术结合是解决问题的途径之一。而专家系统开发工具(平台)是农业信息技术的关键技术之一,它作为一种开发专家系统的通用工具,使农业领域专家无需掌握过多的编程知识就能建造性能良好的专家系统,从而能有效克服目前农业标准化生产中存在的问题。基于此介绍了将农业标准化生产和专家系统开发平台结合起来建立农业标准化生产管理系统开发平台的建立基础、设计思路、技术路线以及平台功能,并阐述了农业标准化生产管理系统开发平台的应用前景。 相似文献