我国热带作物机械的发展现状与对策

热带作物机械化是农业机械化和农业工程学科的一个主要组成部分,发展热带作物机械化对全国热区农垦乃至新农村建设都具有现实意义。为此,依据历年统计数据,阐述了热带作物机械的发展现状及存在的问题,并结合当前热带作物机械行业发展形势,提出针对热带作物机械发展的建议与对策。     

Epidemiology of a Neotropical rust (Puccinia psidii): periodical analysis of the temporal progress in a perennial host (Syzygium jambos)

The epidemiology of the Neotropical rust caused by Puccinia psidii in the Indian Myrtaceae Syzygium jambos (rose apple) was investigated in central Brazil. Disease severities recorded during a 12-month period were fitted by a Fourier curve with three cyclic components or harmonics. The first, second and third harmonics accounted for 49·6, 25·9, and 1·5% of total disease measured, respectively. A highly significant linear correlation was observed between the first harmonic and the accumulated number of days having at least 6 h wetness, or a minimum of 90% relative humidity, combined with temperatures that ranged from 18 to 20°C. No significant correlation was observed between the second and third harmonics and the weather variables evaluated. Rose apple trees showed a flush of growth with new susceptible host tissue during the evaluation period, with two major outbreaks of rust of variable intensity. Host growth was fitted by a Fourier curve with two significant harmonics. The first and second harmonics accounted for 37·5 and 22·1% of total host growth measured, respectively. A highly significant negative linear correlation was observed between the first harmonic and daily maximum and minimum temperatures, rainfall, and duration of the light period. Inoculum availability was not a limiting factor for disease progress since urediniospores were present during most of the period studied. A major peak in numbers of rust spores followed the main peak of disease severity. Thus, rust epidemics on rose apple in central Brazil were shown to depend on the duration of leaf wetness in the dark, and also on night-time temperatures during that same wetness period. This study is the first example of a periodical analysis of an epidemic in a perennial crop.     

BMY牛的选育进展

总结了经历20多年选育的BMY牛所取得的进展,再通过3～5年的努力将完成BMY牛的培育,届时BMY牛将是一个适应我国南方炎热地区的热带肉牛新品种.     

生根阶段组培微环境变化对蝴蝶兰组培苗驯化的影响

在生根阶段对蝴蝶兰组培苗进行不同蔗糖、CQ浓度和光照处理后，影响蝴蝶兰组培苗的驯化过程的植株生长和光合生理。研究表明，提高组培环境中CQ浓度有效改善组培苗的光合能力利于组培苗的移栽适应性。     

Performance of Legume Mixtures under Small-plot Periodic Grazing

The potential of pastures sown with species mixtures of tropical legume species compared with single species was investigated in subhumid west Africa, over a period of three grazing seasons. Through compensation and complementation of the individual legume species, the mixtures were seasonally and temporally (seasonal refers to different seasons in a year, temporal to different years) more stable than the single species stands. Crude protein contents of individual legumes in the mixtures were higher than of the same species grown in single stands, indicating possible synergistic effects in the mixtures. The ability of legume mixtures to withstand environmental and management variations and, thus, their subsequent potential for on-farm utilization under farmers' conditions are discussed.     

建立仿生型兰花驯化园的研究

仿野生兰花的生长环境，选择适宜的林地小气候条件建立兰花驯化园，在不搭荫棚、不搭防雨棚下、使地产兰花在林内安全越冬，既达到了保护野生兰花种质资源和合理开发利用的目的，又节约了建园投资用80％～90％，为山区农民节省耕地、养兰政官提供了一条新门路。     

加快云南热作产业发展的思考

概述了云南主要热带、亚热带作物的生产现状及存在问题,提出加速该省热作产业健康发展的思路和主要措施.     

元江冬季露地切花唐菖蒲大面积栽培实验研究

１９９５年１０月至１９９６年３月利用云南元江低热河谷气候进行唐菖蒲冬季露地生产性栽培试验，证明具有开花早，花色好，新母球发育健壮以及投资成本低等优点，具有较好发展前景。     

中国热带森林的分布、类型和特点

分析了中国热带森林的分布、类型和特点。中国热带林业的几个基本数据：热带有林地总面积为1125．66万hm2；热带林分面积为1074．49万hm2；热带天然林总面积为607．38万hm2；热带人工林总面积为467.11万hm2；热带林木总蓄积为6．6亿m3。中国热带森林面积在世界各国中约占第18位。并针对中国热带森林的特点．提出了中国热带森林的经营对策。     

Forest vegetation of Xishuangbanna, south China

1 Introduction The tropical area of southern China is climatically and biogeographically located at the northern edge of tropical Asia, including southeastern Xizang (Tibet, lower valleys of the southern Himalayas), southern Yunnan, southwestern Guangxi, southern Taiwan and Hainan Island. The largest tropical area still covered by forests is in southern Yunnan. Tropical forests of southern Yunnan were little known until the late 1950s because of poor access except for some brief descrip-…