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The chilli thrips Scirtothrips dorsalis (Hood) (Thysanoptera: Thripidae), a new invasive pest in the USA, is an economically important pest of certain vegetable, ornamental and fruit crops in southern and eastern Asia, Oceania and parts of Africa. These crops cannot be protected from the pest without resorting to the use of chemical insecticides. In order to forestall or delay the development of insecticide resistance in S. dorsalis, we continued our focus on the discovery of insecticides with different modes of action for rotational use. In this study we evaluated candidate insecticides to control S. dorsalis on ‘Jalapeno’ pepper, Capsicum annuum L.; these materials belong to different IRAC mode of action classes as follows: (i) 4A – neonicotinoids, i.e., imidacloprid, thiamethoxam and dinotefuran, (ii) 5 – spinosyns, i.e., spinosad and spinetoram, (iii) 3A – pyrethroids, i.e., β-cyfluthrin, esfenvalerate, ζ-cypermethrin and λ-cyhalothrin and (iv) 8D – borax mixed together with orange oil and detergents in the TriCon® formulation. In addition we evaluated the entomopathogenic fungus, Beauveria bassiana (Botanigard®) alone and in combination with the borax formulation at ½ of their usual rates of application. Each of the 3 neonicotinoid insecticides when applied either as a single foliar spray or as a soil drench significantly suppressed both adults and larvae for at least 10 days; indeed imidacloprid did so for 15 days. Dinotefuran was more effective as a foliar spray than as a soil drench. Spinosyns applied as a single foliar spray, significantly suppressed both adults and larvae through 15 days after treatment (DAT). None of the 4 pyrethroids provided significant suppression of either adults or larvae. The borax formulation suppressed adults and larvae through 10 DAT. B. bassiana significantly suppressed only the larvae at 5 DAT and not at 10 DAT. This study brings the number of insecticides known to be effective against S. dorsalis to 10 and these belong to 7 different modes of action classes. The use of such insecticides in rotation belonging to different classes will help delay the development of insecticide resistance in S. dorsalis. 相似文献
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硫磺、硫酸锌、硼砂施用量与玉米淀粉含量关系的研究 总被引:2,自引:0,他引:2
采用二次回归通用旋转组合试验设计,分析硫磺、硫酸锌、硼砂不同施用量对高淀粉玉米淀粉含量的影响。结果表明:硫磺、硫酸锌与玉米淀粉含量的关系符合二次曲线,硼砂与淀粉含量为正的线性关系;单独施用时,硫磺和硫酸锌降低淀粉含量,硼砂增加淀粉含量;硫磺与硫酸锌存在正向互作,与硼砂存在负向互作;硫酸锌与硼砂不存在互作。淀粉含量高于76.39%的施肥方案是硫磺、硫酸锌、硼砂用量分别为6.39~31.56、8.2~32.0、22.4~28.5 kg/hm2。 相似文献
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改良甲亚胺H酸法快速测定豆奶中硼砂 总被引:1,自引:0,他引:1
[目的]建立快速测定豆奶中硼砂的新方法。[方法]以市售豆奶为样品,经碱化、碳化、灰化,以5ml5%HCl溶解其灰分,使硼砂转化为硼酸根离子,用甲亚胺H酸作显色剂,在波长420n/n处测定其吸光值。[结果]试验表明,样品中硼酸浓度在0—0.500mg/ml线性良好,线性相关系数为0.9991,其加标回收率为97.04%-99.58%,相对标准偏差(RSD)为1.53%。3.69%。最低检出限浓度1.83mg/kg。与姜黄素分光光度法比较,差异无显著性(t=1.800,P〉0.05)。[结论]该法所需试验设备简单,避免了繁琐的浓缩步骤,节约了大量乙醇,灵敏度及准确性均能满足分析要求,适用于大批量豆奶中硼砂的检测。 相似文献
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A new concept for controlling parasitic weeds is described. By decomposing germination stimulants prior to action no germination of seeds can take place anymore. Ethanol fractions of the strigolactone (SL) analogues viz., the standard synthetic analogues GR 24 and Nijmegen-1, and analogues derived from tetralone and coumarine, were added to an aqueous buffer with a pH ranging from 6 to 8 and the half lifes (t1/2) of the hydrolysis were measured. Nijmegen-1 hydrolysed faster than GR 24 and the analogue from tetralone was the most stable one at all pH's. It was found that the aqueous solutions of either borax or thiourea rapidly decompose typical SL analogues, including GR 24 and Nijmegen-1, within an hour. The hydrolysis of SLs by borax was monitored with UV spectroscopy and for thiourea gas chromatography was used. This decomposition of SLs by either borax or thiourea in natural conditions would deprive the seeds of the parasitic weeds of the essential germination stimulants and as a consequence not allow them to germinate. Hence, conditions for an effective weed control are fulfilled. 相似文献
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Basoglu A Sevinc M Birdane FM Boydak M 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2002,16(6):732-735
The effects of sodium borate (100 mg/kg body weight, p.o., 15 days) from a month before expected calving until a month after calving were evaluated in dairy cows susceptible to fatty liver. Cows received either sodium borate (n = 13) or no treatment (n = 10). All cows had mild fatty livers and increased plasma triglycerides and very low density lipoprotein (VLDL) concentrations at the beginning of the experiment. The control group of cows developed significant fatty liver after calving, and 2 of them had severe fatty liver associated with clinical and biochemical abnormalities. There were no clinicopathological signs related to sodium borate administration. Serum triglycerides and VLDL concentrations before calving decreased significantly at calving and after calving in controls, and they were within the normal range only after calving. There were significant alterations during the experiment in some hematological and chemical variables between groups, within period, but they were within the normal range. Unlike treated cows, serum triglycerides and VLDL concentrations correlated with liver fat content after calving in untreated cows. Our results document that sodium borate decreases the degree of fatty liver in dairy cows during early lactation. 相似文献
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[目的]利用硼、钼及稀土微肥对五味子[Schisandra chinensis(Turcz.)Baill.]进行成花调节,并分析其对产量的影响。[方法]采用完全随机区组设计,共设9个不同浓度的微肥试验处理,分别为:硼肥低(2 000 mg/L)、中(4 000 mg/L)和高浓度处理(6 000 mg/L),钼肥低(1 000 mg/L)、中(3 000 mg/L)和高浓度处理(5 000 mg/L),稀土低(100 mg/L)、中(300 mg/L)和高浓度处理(600 mg/L),以蒸馏水处理作为对照。[结果]稀土高浓度处理在提高总花数方面为最佳,比CK增长53.02%,但并不能有效调节雌雄花比例;硼肥中浓度处理在提高五味子雌花数和单株产量上最佳,雌花数比CK增加了151.76%,单株产量比CK增加了65.43%;与CK相比,钼肥能提供五味子总花数、雌花数和单株产量,但增量与硼肥与稀土相比不显著。[结论]该研究为提高五味子雌花率和产量提供了有效的技术措施。 相似文献