Approximating the degrees of freedom for contrasts of genotypes laid out as subplots in an alpha-design in a split-plot experiment     

J. SPILKE  H. P. PIEPHO  U. MEYER 《Plant Breeding》2004,123(2):193-197

Alpha‐designs have become popular in cultivar trials. Analysis is based on a mixed model. As a result of imbalance, inference tests require approximate methods. This paper investigates the Type I error control of different Satterthwaite approximations for the denominator degrees of freedom of Wald‐type F‐tests and t‐tests in a two‐factorial alpha‐design with cultivars as the subplot factor and management intensities (fertilization, plant protection) as the main plot factor. Simulation results demonstrate good error control for cultivar comparison at the same intensity, with the need for an approximation which diminishes as the number of cultivars increases. By contrast, a comparison of intensities entails a more substantial departure from the nominal significance level, and this is not entirely offset by any of the approximations. The methods are demonstrated using two real data sets.  相似文献   

湿地松半同胞家系对轮伐中期追肥的生长响应     

郭文冰  赵奋成  钟岁英  邓乐平  谭志强  容仁立  李振  李义良  吴惠姗 《华南农业大学学报》2017,38(1):90-95

【目的】分析轮伐中期施肥处理对湿地松Pinus elliottii半同胞家系生长的影响,比较磷肥与石灰的肥效差异。【方法】对13年生的湿地松半同胞子代测定林设置氮钾(对照)、氮钾+钙镁磷肥、氮钾+石灰3种施肥处理,分析了土壤和针叶的养分以及湿地松生长性状。【结果】轮伐中期施肥对株高、胸径及单株材积均有显著性影响,处理与家系的互作效应不显著。与对照相比,钙镁磷肥和石灰均促进了株高的生长,分别提高37.1%和29.5%;石灰可以促进材积增量,与对照相比,材积增量提高了22.5%,且石灰处理的胸径增长高于钙镁磷肥处理。【结论】轮伐中期可通过追施氮钾+石灰增加湿地松出材量;石灰对湿地松生长的促进可能与磷有关,与钙无关。  相似文献   

SPSS18.0在裂区试验结果方差分析中的应用     

龚学臣 《河北北方学院学报(自然科学版)》2014,(5):52-54,58

为寻找SPSS软件对裂区试验资料进行方差分析的方法,以实例介绍了SPSS软件利用一般线性模型(GLM-Univariate)模块,通过菜单操作的方式实现裂区试验资料各变异来源的F测验与主效应的多重比较、两个因素间交互效应图的制作方法。  相似文献   

Influences of past application rates of nitrogen and a catch crop on soil microbial communities between an intensive rotation     

Weishou Shen  Nan Gao  Ju Min  Weiming Shi  Xinhua He 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2016,66(2):97-106

The aim of this study was to investigate influences of six-year past application rates of nitrogen and a catch crop, sweet corn (Zea mays L. ssp. Saccharata Sturt), on soil microbial community and diversity in a greenhouse-based intensive vegetable soil in eastern China. Soil electrical conductivity, pH, mineral nitrogen, phospholipid fatty acids (PLFA) profiles and carbon source utilization patterns under five annually past nitrogen rates (0, 348, 522, 696 and 870?kg?nitrogen?ha^?1) were evaluated after the establishment of sweet corn during 1–1.5-month fallow period over three-year tomato/cucumber/celery rotations. The past nitrogen application rates exerted significant effects on soil electrical conductivity, pH, nitrate-nitrogen, ammonium-nitrogen and carbon source utilization patterns, but not on PLFAs profiles. The sweet corn had a significant effect on soil chemical properties, total and actinobacterial PLFAs, but not on carbon source utilization patterns. Soil electrical conductivity, nitrate-nitrogen and the total PLFAs decreased whilst soil organic carbon, pH and the actinobacterial PLFAs increased after the establishment of sweet corn. Soil microbial functional diversity from carbon source utilization patterns and actinobacterial PLFAs were greatest after the establishment of sweet corn at a 60% of the conventional nitrogen rate (i.e. 522?kg?nitrogen?ha^?1). Soil electrical conductivity and ammonium-nitrogen were two key factors to determine carbon source utilization patterns, whilst soil pH was the key factor to determine PLFAs profiles. A combination of the catch crop sweet corn during summer fallow and a 60% of the conventional nitrogen rate is a sustainable pathway of utilizing greenhouse-based intensive vegetable soils in eastern China.  相似文献   

几个杨树新品系抗寒性测定试验   总被引：2，自引：2，他引：0  

李晶  王福森  李树森  苏晓华  张冰玉  黄秦军 《防护林科技》2012,(1):59-61

采用裂区试验设计,对近年在各地试验林内表现较好的8个杨树新品系进行人工低温冷冻试验和冷冻后生长恢复试验,检验它们的抗寒性。以不同温度为主处理,设置-25℃、-30℃、-35℃、-40℃等4个温度梯度,设置3个大区(3次重复),以不同品种为副处理,安排8个杨树品种(品系)。结果表明,不同温度和品系间电解质渗出率差异都极显著,当受到低温影响时,随着温度的降低参试品系的电导率都有不同程度的加大,抗寒性较强的品系增大的程度较小,抗寒性较弱的品系增大的程度较大。  相似文献   

不同耕作方式和插秧方式对中稻＂两迁害虫＂发生和产量的影响     

余永志  宋国锋  钟爱荣 《农林科学实验》2013,(24):131-132,134

为研究不同耕作方式和插秧方式对中稻两迁害虫和中稻产量的影响,特采取裂区试验设计的方法在黄州区开展田间试验。结果表明：牛耕与机耕2种耕作方式对稻飞虱发生量影响不大,但牛耕方式下稻纵卷叶螟发生重;人插秧方式下稻飞虱发生量显著高于机插、抛秧2种方式,而人插秧方式稻纵卷叶螟反而危害轻一些。机耕方式产量显著高于牛耕：机插秧方式平均产量极显著地高于人插秧和抛秧。在黄州区中稻生产中推荐机耕机插栽培方式。  相似文献   

不同施肥量与种植密度对夏玉米产量及效益的影响   总被引：9，自引：0，他引：9  

王建华  高凤菊 《杂粮作物》2009,29(6):407-409

为了探索夏玉米在德州地区的最优栽培模式,采用裂区设计,对不同施肥量与种植密度时夏玉米的产量及效益的影响进行了试验研究。结果表明,施肥量及密度对夏玉米产量的影响均达到显著水平,且肥料和密度的互作效应显著。产量达629．58kg／667m2且效益最大的栽培措施是：追施氮肥30．4kg／667m2,种植密度4000株／667m2。  相似文献   

黑色素与生物农药配伍优化及其对棉田产量的影响     

朱静  张志东  刘晓静  唐琦勇  王博  顾美英  宋素琴  王玮  张丽娟 《新疆农业科学》2018,55(9):1728-1736

【目的】研究天然黑色素对生物农药的光保护作用,提高生物农药药效,降低农药使用量。为推广天然黑色素在生物农药中的应用提供科学依据。【方法】利用出芽短梗霉MF1发酵获得天然黑色素,在农田小区试验条件下,以生物农药浓度为主处理,黑色素浓度为副处理的裂区试验,确定其最佳配伍,分析其对棉田产量的影响。【结果】当每667 m²棉田使用Bt 25 g、阿维菌素5 mL、甲维丙溴磷12.5 g,黑色素2.5 g时,蚜虫杀死率最大可达到97.7%,最大棉花产量可达14.3 kg/小区,显著高于对照小区。【结论】添加天然黑色素不仅可降低生物农药的使用量,同时具有提效增产的作用。  相似文献