Development of Pleospora allii on Garlic Debris Infected by Stemphylium vesicarium

Pseudothecia of Pleospora allii developed best on garlic leaf debris infected by Stemphylium vesicarium incubated at low temperature (5–10°C) and relative humidity (RH) close to saturation. RH of less than 96% prevented the formation of pseudothecia, while an incubation temperature of 15–20°C led to the early degeneration of pseudothecia. Under natural conditions, colonization by pseudothecia of unburied garlic leaf debris varied between seasons from 6.0 to 15.5 pseudothecia/mm2, whereas lower colonization levels were recorded when samples were buried. Pseudothecial maturity was reached 1–4mo after the deposition of garlic debris on the soil surface and 15 days after the burial of residues. In the later case, pseudothecia degenerated with degradation of the plant debris. Ascospore release, which required rainfall or dew periods, occurred between late January and late April depending upon the year. A high correlation was found between pseudothecia maturation and four meteorological variables. Two of which, i.e. the number of hours with RH98% and with a mean temperature of 4.5–10.5°C, and the accumulated rainfall, explained most variability (adjusted R2=0.82–0.98 depending upon the year). A multiple regression equation relating the pseudothecia maturity index with these two variables could be used to forecast the epidemic onset of Stemphylium leaf spots in Southern Spain. Temporal progress of pseudothecia maturation was best fitted by a monomolecular model.     

Reviews

Books reviewed: H.W. Arndt and Hal Hill (eds), Southeast Asia’s economic crisis: Origins, lessons and the way forward William Cline, Trade and income distribution Morris Goldstein, The Asian financial crisis: Causes, curses and systemic implications Lamont Lindstrom and James Gwero (eds), Big Wok: Storian blong Wol Wo Tu long Vanuatu     

潞江坝胡椒种植面积严重萎缩原因分析及发展建议

自20世纪80年代起,云南保山潞江坝胡椒种植面积逐渐萎缩,经调查分析,该地区冬春季节低温干旱的气候条件、管理粗放、连作障碍等导致胡椒旱衰和死亡是种植面积大幅萎缩的主要原因;作者在此基础上提出了该区胡椒产业发展的建议。     

西双版纳香荚兰荫棚种植的气象效应

根据2003年11月-2004年10月对云南西双版纳勐仑香荚兰种植基地的荫棚内外实测的气象资料, 初步分析香荚兰荫棚种植的光、温、湿效应:荫棚种植有效地遮挡了阳光直射,满足了香荚兰对光的需求; 而且荫棚内各种温度明显比棚外为高,弥补了当地年均温比原产地稍低的不足,有利于香荚兰安全过冬; 但棚内抑制植物生长的≥35℃的高温日数增加近30d,容易对香荚兰开花结荚有不利影响;荫棚对相对湿度的影响甚微。     

气象因子对马尾松飞播造林成效的影响

在对安徽省岳西、金寨、责池等11个县（市、区）1991—1992年马尾松飞播造林播区，开展飞播当年出苗调查和飞播3a后成效调查的基础上，通过收集飞播造林当年至成效调查前气象实况数据，就飞播造林成效与气象因子进行逐步回归分析，找出影响飞播造林成效的主导因子，并进行了进一步分析。     

中国东部沿海地区猛禽迁徙与天气、气候的关系研究

通过1980～1987年秋季在大连老铁山、山东省长岛县大黑山岛及青岛浮山的观察研究,确认猛禽的迁徙与气候、天气有着密切的关系。猛禽迁徙通常选择在风力三级(14 km/h)以上西北风或南风的有利天气条件下顺风或侧顺风迁徒。这种大气环流形势在天气图上的反映是地面冷锋过境后当天或次日。冷锋过境前的天气特征是偏南风或西南风,气温升高,冷锋过境后风向转为西或西北风,同时气温下降,气压升高,风速加大。5～6级西北风(30～40 km/h)天气会出现猛禽大规模迁徙过境。故在猛禽的研究中,可根据这种天气变化模式进行猛禽迁徙的预报。     

天气变化情形下基于动态时间窗的收获机应急调度技术

在小麦收获时期,若遇到天气变化,小麦可收获时间窗会发生改变,若还按原调度方案,将造成大量农田延迟收获,从而给农户带来损失。为避免或降低因天气变化给农户带来损失,本文考虑天气变化导致的农田收获时间窗变动的应急调度问题。基于天气变化导致的农田可作业时间窗实际缩短的情况,综合考虑收获机转移时间、提前到达等待时间和延迟时间,建立因天气变化导致的时间窗变动的收获机多目标应急调度模型,引入农田收获应急度函数,确定应急农田,将可作业时间窗和下雨时间有交集的农田重新根据应急度排序进行优先调度。针对此模型特点对遗传算法进行改进,设计基于改进遗传算法的收获机应急调度算法,采用两级多段编码方式及单点交叉方式,使算法可以有效避免局部最优,能够很好地实现全局收敛。通过动态改变原收获机收获路线,为应急农田优先提供收获服务,从而提高农机合作社服务能力,减少农户损失。实例仿真结果证明了模型和算法的可行性。     

Rainfall erosivity and erosivity density through rainfall synthetic series for São Paulo State,Brazil: Assessment,regionalization and modeling

Rainfall is the main cause of erosion of Brazilian soils, which makes assessing the rainfall erosivity factor (RE) and the erosivity density (ED) fundamental for soil and water conservation. Therefore, the objectives of this study were: i) to estimate the RE and ED for São Paulo State, Brazil, using synthetic series of pluviographic data; ii) to define homogeneous regions regarding rainfall erosivity; and iii) to generate regression models for rainfall erosivity estimates in each of the homogeneous regions. Synthetic series of pluviographic data were initially obtained on a sub-daily scale from the daily rainfall records of 696 rainfall gauges. The RE values were then estimated from the synthetic rainfall data, and ED was calculated from the relationship between erosivity and rainfall amounts. Monthly and annual maps for RE and ED were obtained. Hierarchical clustering analysis was used to define homogeneous regions in terms of rainfall erosivity, and regionalized regression models for estimating RE were generated. The results demonstrate high spatial variability of RE in São Paulo, where the highest annual values were observed in the coastal region. December to March concentrate approximately 60% of the intra-annual erosivity. The highest values of annual ED were observed in regions with intense agricultural activity. The definition of five homogeneous regions concerning the rainfall erosive potential evidenced distinct seasonal patterns of the spatial distribution of erosivity. Finally, the high predictive accuracy of the regionalized models obtained characterizes them as essential tools for reliable estimates of rainfall erosivity, and contribute to better soil conservation planning.     

淄博雾霾天气的气候变化特征及成因分析(英文)

对雾霾的定义、雾霾的区别与联系以及雾霾天气形成的原因进行了阐述,并提出了减少雾霾天气的解决对策,为改善城市环境空气质量提供一定的参考依据。     

本溪市区雷暴天气气候特征及其对农业的影响

根据本溪市区46年气象资料的统计分析,总结出了该地区雷暴天气气候规律和特征,并分析了该地区因雷暴天气灾害频发,造成农业诸多方面灾情,影响和破坏了粮食产量质量及农业基础设施;同时,提出利用雷暴天气规律和特征,指导农业生产活动,并提出防御对策。