2008年山西省小地老虎暴发原因分析及防治技术探讨

从虫源基数、气候条件、生态因素、耕作习惯等方面出发,对2008年山西省小地老虎暴发原因做了深入分析。同时结合生产中的经验教训,对小地老虎的防治技术进行了探讨。     

运城地区农田鼠害的发生与防治

对运城地区农田鼠类种群结构、分布、危害情况进行了调查。结果表明,运城地区农田害鼠种群结构为达乌尔鼠、仓鼠、花鼠、子午沙鼠、黑线姬鼠、岩松鼠、中华鼢鼠,优势种为达乌尔鼠、仓鼠,主要发生在山地丘陵、坡地、旱地,且以小麦、油料作物、果树受害最重。并提出了相应的防治方法。     

杀螨药剂防治苹果红蜘蛛田间药效试验

苹果红蜘蛛(以山楂红蜘蛛为主)是山西省苹果树上为害叶片的重要害虫,为了筛选出防效好的无公害药剂,对15%哒螨灵乳油等7种农药进行了田间药剂试验。结果表明,15%哒螨灵乳油杀螨虫效果最佳,25%四螨嗪油杀孵效果最好。因此,施药应根据田间苹果红蜘蛛成螨、若螨、卵不同虫态分布比例状况,选用有效的药剂进行轮换防治。     

桑黑枯型疫病防治新药剂的开发与应用

近几年桑黑枯型疫病在江苏盐城市的蚕桑重点乡镇暴发为害。本试验用已筛选出对桑黑枯型疫病有较好抑制作用的抗菌素进行了开发应用研究。结果表明,安全有效药剂应首选盐酸环丙沙星,其次为盐酸恩诺沙星。使用药剂的经济有效浓度为100 mg/kg,最低有效浓度为12.5 mg/kg,药剂间复配未见有增效作用。用中性偏碱的沟渠中蓄存水稀释药剂,降低防治效果。用喷施两种抗菌素的桑叶喂蚕,未见有叶质降低现象。通过在防治适期内喷施100 mg/kg的盐酸环丙沙星、盐酸恩诺沙星等药剂,配合其它农业防治措施,在盐城市的3个蚕桑重点乡镇的4个中试点上近100 hm2桑园有效地控制了危害。     

莘县保护地土壤养分含量与盐渍化状况分析

通过对保护地栽培的施肥状况、土壤养分含量、pH值和土壤含盐量进行调查和分析,结果表明,保护地施肥过量,养分在土壤中大量积累,土壤次生盐渍化问题比较突出,造成土壤pH值降低,土壤电导率、含盐量增高,已影响到作物的正常生长。结合实际情况提出了相应的防治对策。     

Examining the effects of balloon control ring on ring spinning

The ring spinning process has been used to produce fine and high quality staple fibre yarns. The stability of the rotating yarn loop (i.e. balloon) between the yarn-guide and the traveller-ring is crucial to the success and economics of this process. Balloon control rings are used to contain the yarn-loop, by reducing the yarn tension and decreasing the balloon flutter instability. Flutter instability here refers to the uncontrolled changes in a ballooning yarn under dynamic forces, including the air drag. Due to the significant variation in the length and radius of the balloon during the bobbin filling process, the optimal location for the balloon control ring is not easily determined. In order to address this difficulty, this study investigates the variation in the radius of a free balloon and examines the effect of balloon control rings of various diameters at different locations on yarn tension and balloon flutter stability. The results indicate that the maximum radius of a free balloon and its corresponding position depend not only on the yarn-length to balloon-height ratio, but also on yarn type and count. A control ring of suitable radius and position can significantly reduce yarn tension and decrease flutter instability of free single-loop balloons. While the balloon control rings are usually fixed to, and move in sinc with, the ring frame, results reported in this study suggest that theoretically, a balloon control ring that always remains approximately half way between the yarn-guide and the ring rail during spinning can lead to significant reduction in yarn tension.     

天敌对稻飞虱的控制作用及其种群田间消长规律

针对目前辽宁省稻飞虱发生频繁、为害严重等现状,通过调查研究摸清稻飞虱不同种类的危害发生规律,以及稻飞虱天敌种类及其田间消长规律。这些调查研究,可为通过生态调节增强稻田天敌的作用和控制稻飞虱的为害提供理论和实践指导,从而控制或减少稻飞虱的暴发。     

黑龙江省和吉林省马铃薯晚疫病菌对氟啶胺和甲霜灵的敏感性变化

2006-2008年在黑龙江省和吉林省共分离获得61株马铃薯晚疫病菌,测定了这些菌株对交配型、氟啶胺和甲霜灵的敏感性。交配型测定结果显示所有菌株都显示A1交配型。甲霜灵测定结果显示10个菌株(16.4%)显示为敏感性,11个菌株(18.0%)显示为中抗,40个菌株(65.6%)显示为抗性。这说明吉林省和黑龙江省发生的晚疫病菌已对甲霜灵产生抗性。氟啶胺敏感性测定结果表明,不同地区、不同年份分离的马铃薯晚疫病菌对氟啶胺的敏感性无显著差异, 其敏感性呈连续的单峰曲线分布, EC50在0.203 3~0.783 7 μg/mL之间, 最不敏感菌株是最敏感菌株的3.85倍, 平均值为(0.4781±0.0163)μg/mL, 未出现敏感性下降的抗药性群体, 因此可作为马铃薯晚疫病菌对氟啶胺的敏感性基线;83.6%的供试菌株对甲霜灵的敏感性下降, 甲霜灵与氟啶胺之间不存在交互抗药性。测定氟啶胺对马铃薯晚疫病的盆栽防治试验结果表明,氟啶胺可湿性粉剂、氟啶胺悬浮剂和烯酰吗啉能很好地控制晚疫病,防治效果分别为85.71%、87.00%、82.19%,而甲霜灵的为23.92%。     

嘧霉胺对梨黑斑病菌(Alternaria alternata)的毒力及其药效评价

采用菌丝生长速率法测定了嘧霉胺对梨黑斑病病原菌链格孢菌(Alternaria alternata)的毒力,并进行其对梨黑斑病的田间药效试验。结果表明：嘧霉胺对梨黑斑病菌菌丝生长抑制的EC50为0.126 8 μg/mL ;40%嘧霉胺可湿性粉剂250～500 mg/L对梨黑斑病的防效为66%～82%,且该药剂在本试验剂量范围内对梨树安全。     

氯虫•噻虫嗪不同剂型对水稻二化螟、稻纵卷叶螟的防治效果及施用技术

2007-2008年,应用氯虫•噻虫嗪不同剂型防治水稻二化螟、稻纵卷叶螟的田间试验结果表明：0.6%氯虫•噻虫嗪颗粒剂对二化螟的效果较好,但难以控制稻纵卷叶螟危害;40%氯虫•噻虫嗪水分散粒剂可有效防控以上2种虫害且持效期长达30 d。同一时期同等剂量下,各施用1次0.6%氯虫•噻虫嗪颗粒剂、40%氯虫•噻虫嗪水分散粒剂,前者撒施处理对其药效均显著低于后者茎叶喷雾处理。