杀虫药剂田间药效试验方法

杀虫药剂田间药效试验是客观评价杀虫药剂药效的重要依据。本文对杀虫药剂田间药效试验的设计、试验小区划分、杀虫药剂配制和施用、取样、结果调查和分析方法进行了规范性综述,为进行标准的田间药效试验提供依据和参考。     

新疆杏树吐伦球坚蚧的防治指标与田间药效试验

通过对吐伦球坚蚧Rhodococcus turanicus Arch.种群密度与杏树产量的调查和田间药效试验研究得出:40％毒死蜱·机油乳剂对其防治效果较好,7d后的防治效果可达83.99％;初步探明了吐伦球坚蚧的为害损失率,建立了杏树损失率与吐伦球坚蚧种群密度的回归模型为y=24.671Ln (x)-16.56(y为...     

EXCEL在天然产物提取工艺中的应用

正交试验设计是天然产物研究中重要的方法之一,本文介绍了利用Microsoft EXCEL的内部统计函数编制天然产物提取工艺统计分析程序,并以实例说明了该程序的使用方法和应用技巧。结果表明,用户只需输入试验的原始数据,即可快速、准确地进行直观分析和方差分析,并可根据极差值得出最佳工艺条件,所得分析结果与专业统计分析软件DPS对数据进行正交分析相比,二者计算结果基本一致,且该方法不但快捷方便,操作简单,而且结果准确可靠,可大大提高天然产物提取工艺的效率。     

EXCEL在毒力回归计算中的应用

本文介绍了应用EXCEL进行毒力回归分析、计算LC50 ,a,b,相关系数 ,以及SE ,LC50 的 95 %置信区间和共毒系数的方法。     

2011～2017年新农药活性成分及天然产物药效团衍生法在农药分子设计中的应用

统计了全球范围内首次登记日期位于2011～2017年的102种(不包含生物农药)农药活性成分,并以此为研究对象综述分析了SND(Synthetic natural derived)和NP(Natural product)类农药分子的天然产物来源、作用机制及在农药活性分子中的占比等,综合评估天然产物药效团衍生法在农药分子开发设计中的重要性,并在此基础上提供对未来发展方向。     

不同杀虫剂对西花蓟马的室内毒力及田间药效

【目的】西花蓟马是一种世界性的危险性入侵害虫,筛选防治西花蓟马的有效药剂可为生产中科学用药提供依据。【方法】通过室内毒力测定和田间药效试验,测定了2种化学药剂和8种生物药剂对西花蓟马成虫的致死中浓度(LC_(50))和药后不同时期的防治效果。【结果】室内毒力测定依据LC_(50)值将各药剂对西花蓟马的敏感性由高到低依次排序为乙基多杀菌素(0.1958 mg·L~(-1))、印楝素(0.9399 mg·L~(-1))、苦参碱(1.2483 mg·L~(-1))、阿维菌素(1.8096 mg·L~(-1))、高效氯氰菊酯(4.4458 mg·L~(-1))、藜芦碱(10.7628 mg·L~(-1))、鱼藤酮(18.1898 mg·L~(-1))、吡虫啉(46.3964 mg·L~(-1))、松脂酸钠(131.5214 mg·L~(-1))、苏云金杆菌(446.2318 mg·L~(-1));田间药效试验发现,乙基多杀菌素和吡虫啉防治西花蓟马均表现出较强的速效性和持效性,药后1～14 d的防效分别可达84%和73%以上;其次是藜芦碱,药后1～14 d的防效可达48.15%～61.37%;高效氯氰菊酯的防效较低,药后14 d的防效为46.22%;生物药剂阿维菌素、苏云金杆菌、苦参碱、印楝素的速效性均较低,但防效随施药后时间的延长而逐渐上升;鱼藤酮持效性最低。【结论】乙基多杀菌素和吡虫啉可推荐为生产中防治西花蓟马的首选药剂,植物源药剂藜芦碱和生物药剂阿维菌素可作为交替使用药剂。     

杀虫剂对稻纵卷叶螟的室内毒力及田间药效

分别测定了8种杀虫剂对稻纵卷叶螟的室内毒力及田间防效,结果表明:8种杀虫剂对稻纵卷叶螟的LC50为0.671-10171.07mg.L-1,毒力由高到低的顺序为:甲氨基阿维菌素苯甲酸盐>阿维菌素(B1)>氟虫腈>氟铃脲>丙溴磷>毒死蜱>三唑磷>杀虫单。甲氨基阿维菌素苯甲酸盐、阿维菌素(B1)、氟虫腈、氟铃脲对稻纵卷叶螟的毒力分别为杀虫单的15180.7、5619.3、1611.9、997.2倍。在推荐剂量下,氟虫腈、丙溴磷、毒死蜱对稻纵卷叶螟防治效果较好,防效分别达86.11%、84.73%、83.37%。     

四种药剂防治稻飞虱的药效试验

<正> 稻飞虱(褐飞虱、白背飞虱、灰飞虱)是我县水稻上的头号害虫,1987、1988年连续二年在早稻上特大发生,一般百丛禾有虫4500～7000只,局部丘块虫口密度高达15000只/百丛。为     

苹掌舟蛾药效实验的统计分析

苹掌舟蛾（Ｐｈａｌｅｒａ ｆｌａｖｅｓｃｅｎｓ Ｂｒｅｍｅｒ ｅｔ Ｇｒｅｙ）为北方苹果、南方枇杷和梨、桃、李、杏、梅、樱桃、山楂等果树的重要害虫,常致枇杷及光叶石楠受害成灾。本用统计的方法分析了采用农药和病毒防治苹掌舟蛾幼虫的效果。     

三种纳米缓释剂农药对葱蓟马的田间药效评价

葱蓟马Thrips tabaci Lindeman是一种世界性农业害虫,为明确3种纳米缓释剂农药对葱蓟马的防治效果,开展了田间药效评价试验.结果表明,0.7％甲维盐纳米缓释剂(NR)和5％甲维盐微乳剂(ME)对葱蓟马的速效性和持效性较好,3～14 d的防效均达到90％以上;10％高效氯氟氰菊酯NR和5％高效氯氟氰菊酯M...     

Statistical analysis of noninferiority trials with a rate ratio in small-sample matched-pair designs

Testing of noninferiority has become increasingly important in modern medicine as a means of comparing a new test procedure to a currently available test procedure. Asymptotic methods have recently been developed for analyzing noninferiority trials using rate ratios under the matched-pair design. In small samples, however, the performance of these asymptotic methods may not be reliable, and they are not recommended. In this article, we investigate alternative methods that are desirable for assessing noninferiority trials, using the rate ratio measure under small-sample matched-pair designs. In particular, we propose an exact and an approximate exact unconditional test, along with the corresponding confidence intervals based on the score statistic. The exact unconditional method guarantees the type I error rate will not exceed the nominal level. It is recommended for when strict control of type I error (protection against any inflated risk of accepting inferior treatments) is required. However, the exact method tends to be overly conservative (thus, less powerful) and computationally demanding. Via empirical studies, we demonstrate that the approximate exact score method, which is computationally simple to implement, controls the type I error rate reasonably well and has high power for hypothesis testing. On balance, the approximate exact method offers a very good alternative for analyzing correlated binary data from matched-pair designs with small sample sizes. We illustrate these methods using two real examples taken from a crossover study of soft lenses and a Pneumocystis carinii pneumonia study. We contrast the methods with a hypothetical example.     

Quantifying pesticide efficacy from multiple field trials

Simple corrected density indices (CDIs) have been used to measure reductions in pest density in fields. In the contemporary pesticide registration system, few comprehensive statistical frameworks are available that can integrate multiple datasets to evaluate how pesticidal effects are influenced by the products' properties such as mixing multiple active ingredients and possession of systemic ability. In this study, we provide a statistical framework for evaluating pesticide efficacy from multiple field trials and applying it to contemporary pesticides. In this framework, we extended the conventional CDI to a generalized linear mixed model (GLMM), which we applied to a dataset of the pesticide registration test in Japan (n = 758). The estimated mortality of a single active ingredient in reducing pest density is 88.0%, indicating the registered pesticide satisfies the “effective” criterion (roughly 70–95%) under the current pesticide registration system in Japan. Although systemic ability additionally reduced pest population to 55.5% of the post-treatment densities, the addition of active ingredients scarcely enhances efficacy (reducing population to 74.6%), suggesting that the pesticide design resulted in broadening the spectrum of target species rather than increasing toxicity.     

Statistical methods suitable for the analysis of plant tissue culture data

Statistical analyses are an essential part of biological research. Statistical methods are available to biological researchers that range from very simple to extremely complex. Therefore, caution should be used when selecting a statistical method. When possible it is best to avoid complicated statistical procedures that are difficult to interpret and may hinder the researcher's ability to make treatment comparisons. Instead a method should be chosen that compliments a logical and practical treatment design. Statistics should be used as a tool to compare treatments of interest and should not dictate the treatments. Experimental designs should take into account the eventual analysis, otherwise one could conceive of a design that could not be analyzed or, when analyzed, would not answer the desired questions. Therefore, time should be spent before conducting an experiment to plan an experimental design and analysis that best compliments the treatment scheme and questions to be answered. The purpose of this paper is to present examples of experimental designs, means separation procedures, data transformations and presentation methods suitable for plant cell and tissue culture data.Abbreviations ANOVA analysis of variance - BA benzyladenine - CV coefficient of variation - DF degrees of freedom - IAA indole-3-acetic acid - IBA indole-3-butyric acid - LOF lack-of-fit - MSE mean square error - P-ITB phenyl indole-3-thiolobutyrate - S standard deviation - SE standard error of the mean - TDZ thidiazuron     

Statistical inference for self-designing clinical trials with a one-sided hypothesis

In the process of monitoring clinical trials, it seems appealing to use the interim findings to determine whether the sample size originally planned will provide adequate power when the alternative hypothesis is true, and to adjust the sample size if necessary. In the present paper, we propose a flexible sequential monitoring method following the work of Fisher (1998), in which the maximum sample size does not have to be specified in advance. The final test statistic is constructed based on a weighted average of the sequentially collected data, where the weight function at each stage is determined by the observed data prior to that stage. Such a weight function is used to maintain the integrity of the variance of the final test statistic so that the overall type I error rate is preserved. Moreover, the weight function plays an implicit role in termination of a trial when a treatment difference exists. Finally, the design allows the trial to be stopped early when the efficacy result is sufficiently negative. Simulation studies confirm the performance of the method.     

An adequate design for regression analysis of yield trials

Summary Based on theoretical demonstrations and illustrated with a numerical example from triticale yield trials in Portugal, the Completely Randomized Design is proposed as the one suited for Regression Analysis. When trials are designed in Complete Randomized Blocks the regression of plot production on block mean instead of the regression of cultivar mean on the overall mean of the trial is proposed as the correct procedure for regression analysis. These proposed procedures, in addition to providing a better agreement with the assumptions for regression and the philosophy of the method, induce narrower confidence intervals and attenuation of the hyperbolic effect. The increase in precision is brought about by both a decrease in the t Student values by an increased number of degrees of freedom, and by a decrease in standard error by a non proportional increase of residual variance and non proportional increase of the sum of squares of the assumed independent variable. The new procedures seem to be promising for a better understanding of the mechanism of specific instability.     

Exploratory analysis of longitudinal trials with staggered intervention times

Longitudinal trials involving surgical interventions commonly have subject-specific intervention times, due to constraints on the availability of surgeons and operating theatres. Moreover, the intervention often effects a discontinuous change in the mean response. We propose a nonparametric estimator for the mean response profile of longitudinal data with staggered intervention times and a discontinuity at the times of intervention, as an exploratory tool to assist the formulation of a suitable parametric model. We use an adaptation of the standard generalized additive model algorithm for estimation, with smoothing constants chosen by a cross-validation criterion. We illustrate the method using longitudinal data from a trial to assess the effect of lung resection surgery in the treatment of emphysema patients.