合浦县木薯旱地高产栽培技术及发展建议

SUN Yi-xiang(Institute of Agricultural Sciences of Hepu County, Hepu, Guangxi 536100)     

植物源农药苦参碱对部分桑园害虫的毒力及田间防治效果

为了探讨从传统中草药苦参中提取的苦参碱用于桑树害虫防治的可行性,用2%苦参碱稀释药液对部分桑园害虫进行室内毒力测定和田间防治试验,并检测其对家蚕的安全性。结果表明,2%苦参碱对桑尺蠖、桑毛虫、棉大造桥虫、红腹灯蛾、白毛虫有较强的毒力,其LC50分别为23.55、28.73、28.52、30.71、25.61 mg/L,以1 500倍稀释药液对上述5种害虫室内处理24 h后的死亡率为92.18%～96.78%,并且具有较好的田间防治效果,24 h虫口退减率为89.81%～96.00%;对桑园微型害虫桑蓟马和朱砂叶螨也有较强的毒力和防治效果,1 500倍稀释药液室内处理24 h后的死亡率分别为95.52%、98.07%,田间防治24 h虫口退减率分别为90.61%、92.55%;对桑螟、野桑蚕的毒力较低,LC50分别为364.47和351.01 mg/L,1 500倍稀释药液对2种害虫室内处理24 h后的死亡率仅有3.13%和3.83%,田间防治24 h虫口减退率分别为18.06%、8.70%。用2%苦参碱的2 000倍、1 500倍、1 000倍稀释药液喷施桑树后,对家蚕的安全间隔期分别为4、8、32 h,安全间隔期后采摘桑叶喂蚕,对家蚕的生长发育和产茧量性状无不良影响。根据试验结果初步认为:苦参碱对桑园害虫防治具有选择性药效,如果桑园害虫的优势种群为桑尺蠖、棉大造桥虫、桑毛虫、红腹灯蛾、白毛虫、桑蓟马、朱砂叶螨,可以考虑采用苦参碱进行防治。     

引自国际马铃薯中心的品种资源在青海对晚疫病的田间抗性鉴定

在青海省海拔2000～2500m和2500～3000m两个不同生态区域设置抗性观测圃,调查评价从国际马铃薯中心(CIP)引进的60份资源田间晚疫病抗性,资源D9在整个生育期表现出免疫症状,15个资源表现为高抗,18个资源表现抗病,同时还对晚疫病菌流行生理小种的毒性基因进行动态监测。     

华山新麦草易位系抗黄矮病的鉴定

小麦黄矮病在田间由麦蚜传播大麦黄矮病毒(BYDV)感染引起。为给优质抗BYDV小麦新品种提供重要种质资源,采用堆测法种植材料,利用饲毒蚜虫接种病毒BYDV-GAV的方式,对27份华山新麦草易位系材料进行了抗病性鉴定,比较了接种病毒后各材料的病情指数及其千粒重。结果表明,27份华山新麦草易位系中,5份材料的病情指数介于13.56～18.89,表现为抗BYDV-GAV;9份材料的病情指数是介于27.78～48.89,表现为感BYDV-GAV;其余13份材料的病情指数均大于50.0,表现高感BYDV-GAV。不同华山新麦草易位系对BYDV-GAV抗性差异较大,筛选出的5份抗黄矮病材料可为培育优质抗病毒新品种提供重要种质资源。     

Deposition of spray drift behind border structures

Windbreaks present a porous obstacle to the approaching airflow, forcing air to flow through the windbreak at a reduced speed and accelerate over the top. In this research, windbreaks were considered as border structures to mitigate spray drift. Air flows, with an interspace between it, particles are filtered from the flow by deposition on the windbreak. Hence there is a reduction in deposition in the downwind sheltered area (the ‘quiet zone’) behind the windbreak. Peak deposition in the sheltered area can occur at minimum wind speeds. The deposition profiles of spray drift behind various border structures were measured. In the first part, drift tests were performed in a wind tunnel. Artificial screens with various heights and open areas were tested. A row of plastic Christmas trees and natural canopies were also tested. Subsequently, drift experiments were performed under field conditions in a grassland with the artificial screens and a row of Fagus sylvatica trees. The artificial screens reduced spray drift deposition in the sheltered region, but significant deposition peaks were found behind the screens. The natural structures had potential to reduce drift deposition when their height was at least equal to the height of the spray nozzle(s). The drift deposition at short distances behind the natural structures was higher than deposition behind artificial structures, but conversely peaks in deposition in sheltered areas were not created by the natural structures.     

吉林西部新开水田生物有机肥筛选报告

为促进吉林省西部盐碱地水稻开发,筛选适宜当地新开田的生物有机肥品牌,做此试验。通过对水稻生育性状、产量、病害情况调查,总结出适合当地施用的两种生物有机肥料,以期为稻农正确选用有机肥产品提供科学依据。     

2000年茶业展望

茶是世界上消费量仅次于水的一种饮料。本文从宏观角度分析了世界茶叶生产和茶叶科学的现状,并对２０００年进行展望。全文分茶叶生产、育种、茶园管理、病虫防治、茶叶加工、茶与人体健康六个部分对此进行了讨论。     

Improving the Field Emergence Performance of Super Sweet Corn by Sand Priming

Abstract

A priming method called sand priming was developed using sand as a priming solid matrix. The effect of sand priming on improving the field emergence performance of five super sweet corn cultivars was investigated. Sand priming significantly improved field emergence performance of all super sweet corn cultivars, and there was marked improvement by priming at 20ºC for 24 hr. After sand priming at 20ºC for 24 hr, field emergence percentage (FEP) of “Green Superman”, “Huatian 1”, “Yangtian 1”, “Mitian 8”, and “Chaotian 43” was increased by 52.1%, 37.5%, 38.0%, 40.9%, and 33.3%, respectively. Their field emergence speed (FES) was 2.3, 1.8, 2.0, 2.0, and 1.8 times of the control, respectively. To further elucidate the effect of sand priming on improving the field emergence performance of super sweet corn, we analyzed the membrane system integrity, α-amylase activity and protein content. Sand priming at 20ºC for 24 hr improved membrane system integrity and α-amylase activity in all super sweet corn cultivars. Furthermore, sand priming at 20ºC for 24 hr accelerated the degradation of embryo protein after 1 d germination in “Green Superman”.     

8种农药防治烟草花叶病的田间药效试验

采用病毒必克、病毒清、抗毒丰、倍达、宁南霉素、氨基寡糖素、克威特灵、超敏蛋白8种药剂,分别在烟草苗期、大田期进行田间药效试验,结果表明:8种药剂对烟草花叶病均有一定的防治效果,其中氨基寡糖素、克威特灵、超敏蛋白的防效相对较好,平均防效分别为55.64%、53.75%、50.81%,且防效较稳定,具有一定的推广应用价值。     

7种杀虫剂防治烟蚜药效研究

[目的]筛选出对烟蚜防治效果好的杀虫剂。[方法]以虫口减退率和防治效果为评价指标,在田间对3%啶虫脒EC、5%吡虫啉EC、24%灭多威AS、0.5%苦参碱AS、灭蚜宁DP、25%噻虫嗪WG和40%氧乐果EC 7种药剂防治烟蚜进行了筛选试验,清水为对照。[结果]7种药剂中,以5%吡虫啉EC 750 g/hm2对烟蚜防治效果最好,药后3、5、7 d对烟蚜校正防效均超过90%,与除3%啶虫脒EC500 g/hm2外的其余药剂校正防效差异达到显著性水平;3%啶虫脒EC 500 g/hm2防效次之,药后5、7 d防效与0.5%苦参碱AS 1 250g/hm2、40%氧乐果EC 937.5 g/hm2差异达到显著性水平。[结论]5%吡虫啉EC与3%啶虫脒EC用于防治烟蚜速效性强,持效期长,显著优于对照药剂氧乐果的防效,是防治烟蚜的理想药剂,且对烟株安全,可在烟草上推广使用。