Overwintering and epidemiology of Puccinia dracunculina,the causal agent of rust in open tarragon fields

Rust, caused by Puccinia dracunculina, is the main foliar disease of open‐field tarragon (Artemisia dracunculus) crops in Israel. As not much is known about the biology or epidemiology of this pathogen, the long‐term objective of the current study was to accumulate the knowledge needed to develop an effective, environmentally friendly means of adequately managing the disease. Puccinia dracunculina is an autoecious brachy‐form pathogen, but it is not known whether the life cycle is completed under field conditions in Israel. Field observations and greenhouse studies revealed that although the telial stage is produced, the pathogen overwinters in the uredinial stage. In vitro experiments were used to quantify the temperature and wetness requirements for urediniospore germination and to calculate the daily duration of conducive weather (DDCW); DDCW was defined as the number of hours during which temperature ranged between 15 and 25°C and RH was >90%. Cumulative DDCW values (CDDCW) were a good predictor of disease under natural conditions in two growing seasons. Disease onset occurred when CDDCW values reached a level of 10 and the relationship between log CDDCW values and season‐long severity values (in logit) was highly significant, explaining 90·6% of the variation.     

Influence of weather factors on sorghum earhead bug Calocoris angustatus Lethierry incidence

Abstract

Weather parameters during the same week and one, two, three or four weeks before were correlated with the population of earhead bug, Calocoris angustatus on different earhead stages of two hybrids, CSH 5 and K‐Tall, in main and ratoon crops. The weather factors in the different weeks contributing to the insect population varied with the stage of earhead, the hybrid and the nature of the crop (main or ratoon). In the main crop, the insect population at pre‐flowering, milky, dough and maturity stage was influenced by weather parameters one week before, the same, two and three weeks before respectively. Morning relative humidity was important in both hybrids at all stages, with a few exceptions. In the ratoon crop, the pre‐flowering and maturity stage populations were influenced by the weather parameters of the same week. The populations at milky and maturity stage were influenced by parameters four weeks and one week before the observations respectively. The factors influencing the population on CSH 5 and K‐Tall varied. In most cases morning relative humidity had a positive influence.     

降尘空间分布与沙尘天气日数关系研究

降尘是沙尘暴、浮尘、扬沙等沙尘天气过程的反映,文中以甘肃省10个监测点15年(1986-2000年)降尘监测数据及沙尘天气日数数据,讨论降尘空间分布与沙尘天气日数之间的相关性,建立降尘与沙尘事件之间的回归方程。结果表明:在沙尘暴区和非沙尘暴区,降尘与沙尘天气的回归方程不同,前者沙尘暴系数(1.32)小于后者沙尘暴与扬沙和的系数(1.66),可以判断后者较之前者降尘量受沙尘暴和扬沙日数影响更大,可以突现出后者沙尘天气主要以浮尘为常态形式出现。前者浮尘系数远大于扬沙系数(3.72>0.21),表明前者降尘量受浮尘影响大于扬沙。前者常数项(291.6)明显大于后者(235.2),这代表两地区降尘量的背景值的不同。回归方程很好地解释了不同地区降尘与沙尘天气日数之间的关系。将降尘与沙尘天气日数的回归方程应用到研究区,求得研究区各气象站点降尘数据,结合GIS空间插值,绘制出该研究区降尘空间分布图。     

红外靶标自动探测器的研制及试验

当前红外靶标自动探测器对绿色作物喷药时,存在对作物和非作物(土壤、枯枝等)都施药的缺陷,造成了药液的浪费和环境的污染。该文探讨用红外探测技术实现对靶标的自动探测,同时以颜色传感器为辅助对绿色靶标进行识别,实现红外靶标自动探测器仅对绿色靶标进行喷雾的目的,试验结果表明:所建立的红外靶标自动探测器可对绿色作物靶标进行自动探测,探测的最远距离为85～88cm;探测距离的远近受叶片覆盖率与照度2因素的影响,植物冠层叶片覆盖率越大时,探测距离越远;叶片表面的照度越高时,探测距离越远;叶片覆盖率越大且照度越大时,探测距离越远且工作越稳定,为绿色作物精准施药提供了一种控制思路及方法。     

基于卫星遥感和自动气象站数据反演稻田气温——以安徽省为例

随着全球气温变暖和高温事件的频繁出现,水稻遭受高温影响的概率也随之增加。稻田气温是研究水稻遭受高温热害及其影响的数据基础。因此,大范围地反演稻田气温,有助于相关部门短时间内获取大范围的稻田气温数据并进行水稻高温热害的研究和决策部署。本文利用MOD09A1 8天合成数据对安徽省水稻种植区域提取,水稻种植区内的自动气象站气温数据与MOD11A1、MYD11A1 4个LST值进行多元逐步回归,得到遥感估算最高气温和平均气温方程最优,R²分别为0.728和0.825,均方根误差分别为(RSME)2.21、1.54,平均绝对误差(MEA)分别为1.73、1.15,最终完成基于卫星遥感信息和自动气象站气温数据反演稻田气温的方法的开发。将该方法应用于2017年安徽省水稻种植区的提取和气温的反演得到了很好的应用。     

鲁西南地区灯诱昆虫种类调查及优势种群动态分析

为了进一步明确鲁西南地区的农业昆虫发生种类及优势种群发生动态,2019年5—9月,笔者在山东省邹城市面坊片区和沈庄片区设置自动虫情测报灯,系统诱集昆虫并鉴定,并对该区域优势种群的发生动态进行分析。诱集结果表明：2019年鲁西南地区灯诱昆虫种类包含6目19科56种,共计53744头昆虫。发生期历时近180天,其中6月中旬—8月下旬为鲁西南地区昆虫的发生盛期,笔者并对危害当地的重要害虫优势种群进行消长动态分析。昆虫优势种群的种类调查和动态分析将有利于及时掌握当地的害虫发生情况,为今后的农业生产提供技术指导。     

埇桥区现代病虫测报体系建设现状与思路

以埇桥区为例,在调查农作物病虫测报体系队伍建设、仪器设施设备配备及测报工作开展等基本情况的基础上,提出了“以乡村为重点,夯实乡级测报站和村级测报点基础的现代病虫测报体系”的建设观点,建议进一步强化区植保站(测报站)建设,重点加强乡镇“测报站”建设,探索村级“测报点”建设和新型农业经营主体的基层“测报员”建设,共同形成埇桥区现代病虫测报网络体系。     

基于系统动力学和联合分析法的中国紧凑型电动车市场前景研究

紧凑型电动车市场的发展水平受到产品技术成熟度、基础设施覆盖率、汽油价格波动和消费者产品接受度等多方面因素的影响。本文应用系统动力学的思想,对我国紧凑型电动车市场的发展机制进行了研究,建立了包含上述影响因素系统动力学模型,并进一步借助基于联合分析法的调研,将消费者观点融入其中。在此基础上对其未来10年的市场发展前景进行了预测研究。     

水稻热带气旋灾害保险气象指数设计

利用登陆广东省的热带气旋(TC)资料、水稻发育期资料及广东省水稻生育期间TC致灾风险等级及其减产率,借用数理统计方法分析TC在水稻不同发育期登陆出现的概率。结果表明:水稻TC灾害保险赔付触发值为热带风暴或强热带风暴在早稻和晚稻后期、台风在早稻和晚稻中期或后期登陆;当热带风暴、强热带风暴在双季稻后期登陆时,水稻TC灾害保险气象指数分别为5、6、7、8,每667 m2赔付金额分别为20、24、28、32元;台风在双季稻中期和后期登陆时,水稻TC灾害保险气象指数分别为6、9,每667 m2赔付金额分别为24、36元。设计水稻热带气旋灾害保险气象指数,为开展水稻政策性农业保险提供技术支撑。     

Effects of irrigation on precipitation in the arid regions of Xinjiang,China

Soil moisture is an important parameter for the interaction between soil and atmosphere.It is the second important factor that influences climate change,next to sea surface temperature(SST).Most previous studies focused on the monsoon regions in East China,and only a few laid emphases on arid environments.In Xinjiang, which is located in Northwest China,the climate is typically arid and semi-arid.During the past 20 years,the precipitation in Xinjiang has shown a significant increasing trend,and it is closely related to oasis irrigation.This paper aims at discussing whether abnormal soil moisture in spring can be the signal to forecast summer precipitation.The effects of abnormal soil moisture due to farm irrigation in spring in arid environments on regional climate are investigated by using a regional climate model(RegCM3).The results indicate that positive soil moisture anomaly in irrigated cropland surface in May led to an increase in precipitation in spring as well as across the whole summer. The impact could last for about four months.The effects of soil moisture on the surface air temperature showed a time-lagging trend.The summer air temperature declined by a maximum amplitude of 0.8oC.The increased soil moisture could enhance evaporation and ascending motion in the low troposphere,which brought in more precipitation.The soil moisture affected regional weather and climate mainly by altering the surface sensible and latent heat fluxes.