【作者】 田鹏鹏；

【导师】 张兴；

【作者基本信息】 西北农林科技大学 ， 农药学， 2008， 硕士

【摘要】 田间药效试验表明,树干注射4%吡虫啉注干液剂可以有效的防治多种蛀干及食叶类树木害虫。目前关于吡虫啉注射后在树体中吸收分布规律的报道甚少。为科学、合理的利用该药剂防治树木虫害,本文测定了树干自流式注药过程中不同条件下树体对4%吡虫啉注干液剂的吸收;研究了树干注射后吡虫啉在垂柳树体内的分布及持续动态;并通过室内生测,探讨了树干注射吡虫啉对华北大黑鳃金龟成虫的防治效果。主要研究结果如下:1.在晴朗无风的天气条件下,树干自流式注药法中不同条件下树体对药剂吸收结果表明,注药孔孔径及树种对药剂吸收影响较大,其次为树干基径和季节,注药器通气孔孔径对药剂吸收的影响不显著。5 mm注药孔孔径下树体对药剂的吸收显著高于2、3 mm注药孔,注药后10 h树体对药剂吸收一般可达6～8 mL。两种通气孔孔径(0.5、1 mm)下树体对药剂吸收的速度差异较小。9种树种对药剂的吸收能力依次为:毛白杨>白梨>李>侧柏>水杉>悬铃木、国槐、垂柳>合欢。树干基径对药剂吸收的影响因树种而异,国槐表现为基径较大的树体对药剂的吸收能力较强,侧柏与之相反,毛白杨不同基径树体对药剂吸收的差异不显著。5月份树体对药剂的吸收能力高于9月份。2.树干注射后吡虫啉在垂柳体内具有良好的传导性能。在树冠不同高度不同方位叶片中吡虫啉含量差异较大。树冠上层叶片中吡虫啉含量整体高于下层叶片,注药孔上方叶片中吡虫啉含量较树冠其他方位高。在树干木质部吡虫啉向上纵向输导能力较强。在树干基部南侧打孔注药,注药后1 d树干下部南侧木质部中吡虫啉含量高达20.30μg?g-1,是其他三个方位的10倍左右,而在树干中、上部不同方位间的含量差异相对较小。随着传导时间的延长,吡虫啉在树干木质部中快速向上部移动,注药后3 d树干中部含量达到最大,注药后6 d时树干上部含量最大。在树干韧皮部,注药后1 d仅在树干东侧韧皮部中有吡虫啉分布,注药后3 d树干不同高度各方位均有吡虫啉分布,至注药后13 d时树干韧皮部的吡虫啉总含量达到最高。吡虫啉在树干韧皮部的含量低于树干木质部。3.树干注射后垂柳叶片中的吡虫啉总残留量最大,其次为小枝木质部、小枝韧皮部、树干木质部,树干韧皮部的含量最低。在树体不同部位吡虫啉总残留变化趋势不同。在树干木质部吡虫啉总残留呈现逐渐下降的趋势,注药后5 d吡虫啉总残留最高,至注药后30 d处于较低水平。叶片中的吡虫啉总残留呈现先上升后下降的趋势,注药后25 d时达到最高值。树干韧皮部中的吡虫啉总残留量变化幅度较小,在注药后20～40 d保持较高水平高。注药后70 d各组织中吡虫啉总残留量分布相对均衡,处于较低水平。树干注射后吡虫啉及其衍生物在柳树体内持续期较长,有利于对树木害虫发挥长效控制作用。4.垂柳树干注射吡虫啉对华北大黑鳃金龟成虫有较强的击倒作用,持效期较长。结果表明不同时期注射吡虫啉后采摘垂柳叶片饲喂试虫,24 h死亡率呈现波动变化,其中注药后10 d致死率最高为76.67%;不同时期注药对试虫均表现出较强的击倒作用,击倒率均高于65%。叶面喷雾和树干注射施用吡虫啉对华北大黑鳃金龟成虫的LC50值(叶片中吡虫啉含量)分别为6.3368μg?g-1和3.6439μg?g-1,表明树干注射对试虫的毒杀作用更强。可见,4%吡虫啉注干液剂在树体内具有良好的吸收传导性能,田间持期长,是一种具有良好应用前景的树木注干药剂。更多还原

【Abstract】 Field efficiency trials showed imidacloprid as a trunk-injectable insecticide was found to be effective in controlling a number of borers and suck insect pests of trees. However, there are fewer reports about the uptake, translocation, and distribution of imidacloprid with trunk injection at home and abroad. In order to use this trunk-injectable insecticide for controlling insect pests of trees effectively, uptake of imiacloprid liquid formulation by trees under several factors with auto flowing trunk injection, translocation, and distribution of imidacloprid in weeping willow, and efficiency of imidacloprid on adult Holotrichia oblita Fald. in vivo bioassay after injection was determined. The main results as follows:1. Effects of several factors on the uptake of 4% Imidacloprid Liquid Formulation (ILF) by trees was studied with auto flowing trunk injection in sunshine. The results showed injection hole-diameter and tree species had highest impact on the uptake of ILF, and the lowest in injector blowhole-diameter. 5 mm injection hole performed well; generally the uptake of ILF was 6-8 mL at 10 h after injection. Diameter of injector blowhole had less influence on the uptake of ILF. The absorbability to ILF was various in 9 tree species; Populus tomentosa had a most strong ability and the least in Albizia julibrissin. Effect of trunk basal diameter on the uptake to ILF was indefinite, depending on the species, in Sophora japonica the uptake ability to ILF was greater with bigger trunk basal diameter, but in Platycladus orientalis that was reverse, in Populus tomentosa it was not significantly different between trees with different trunk basal diameter. Uptake rates were lower during maturity period (September) than peak growth season (May). All these factors are to be taken into account in order to ensure the most efficient use of auto flowing trunk injection with chemicals in agriculture and forestry.2. Imidacloprid was transmitted well in the weeping willow after trunk injection. Imidacloprid concentration (IC) varied depending on the positions of leaves located. In the upper crown IC were more than those in the lower crown as a whole. 48 h after injection, the gap of IC between upper crown and lower crown reached the maximum. The IC of the leaves upon the injection spot were more than the others sides. The results about translocation of imidacloprid in the xylem and phloem of tree trunk as follow. Imidacloprid was transmitted much effectively in the vertical direction along the xylem. IC in the south xylem at trunk height 0.5～0.9 m was as much as 20.30μg?g-1 at one day after injection, which was almost 10 times more than the other three sides. And the gap of IC among different sides decreased gradually with the trunk height ascending. As the time passed by, the distribution center of IC moved up quickly. At 6 days after injection, IC reached the maximum in the top part of trunk xylem. In trunk phloem imidacloprid was only presented in the east side at 1 day after injection. And imidacloprid was detected in all trunk phloem samples at 3 days after injection. IC reached the maximum in trunk phloem at 13 days after injection as a whole. IC in trunk phloem was less than that in trunk xylem in 20 days after injcetion. In conclusion, Imidacloprid was able to transport in both xylem and phloem.3. The results showed concentration of total imidacloprid residues varied among different tissues of weeping willow after injection. Concentration of total imidacloprid residues in the leaves was the most, next were twig xylem, twig phloem and trunk xylem, and the least in trunk phloem. The trends of total imidacloprid residues concentration in several tissues were different. It decreased gradually in the trunk xylem from 5 days after injection. The total imidacloprid residues concentration in the leaves reached the maximum at 25 days after injection, and gradually declined after immediately rising. The tatoal imidacloprid residues concentration increased slowly in the twig phloem, and reached the maximum at 30 days after injection. In trunk phloem the total imidacloprid residues concentration varied smoothly during 110 days after injection. Since 70 days after injection the total imidacloprid residues concentrations among these five tissues become equal relatively and decreased at a lower level. Imidacloprid and its metabolites after trunk injection into weeping willow could last for 110 days, which is good for controlling insect pests of trees.4. The results showed imidacloprid had strong knock down action against adult Holotrichia oblita (Fald.) with trunk injection into weeping willow, and the persistence was sustained over 80 days. Efficacy of imidacloprid after injection had less lethal effect on test insect; however it took on well at knock down action, and knock down rates of all samples on test insect were all over 65%. LC50 of imidacloprid on adult Holotrichia oblita (Fald.) applied with foliar spray and trunk injection were 6.3368 and 3.6439μg?g-1 respectively, which indicated toxicity of imidacloprid against adult Holotrichia oblita (Fald.) was stronger with trunk injection.To sum up, 4% imidacloprid liquid formulation had better uptake, translocation property and the persistence effect could last for at least 3 months. It is a new kind of trunk-injectable liquid formulation with bright prospect of application.更多还原