Some Design Problems in Crop Experimentation. II. Multiple Blocking Systems

1995 ◽  
Vol 31 (3) ◽  
pp. 279-290
Author(s):  
S. C. Pearce
Keyword(s):  
Field Experiments ◽  
Block Structure ◽  
Design Problems ◽  
Split Plot ◽  
Alternative Approaches ◽  
Simple Block

SummaryThis paper describes the construction, usefulness and randomization of several designs for field experiments in which there is more than one set of blocks, namely: (a) row-and-column designs, in which there are two crossing sets of blocks, treatments being applied to the plots formed by their intersections; (b) row-and-column designs in which factors are applied to complete rows or complete columns, that is, criss-cross (or strip-plot) designs; and (c) split-plot designs, in which the plots in a study of one factor are used as blocks in the study of another. All are examples of a wider class of designs, with many ramifications, said to have ‘simple block structure’. It is suggested here that some of the assumptions underlying row-and-column designs are questionable. Some alternative approaches are indicated.

scholarly journals Interaction of dicamba, fluthiacet-methyl, and glyphosate for control of velvetleaf (Abutilon theopharsti) in dicamba/glyphosate-resistant soybean

2021 ◽  
pp. 1-21
Author(s):  
Jose H. S. de Sanctis ◽  
Amit J. Jhala
Keyword(s):  
United States ◽  
Field Experiments ◽  
The United States ◽  
Application Rate ◽  
Herbicide Application ◽  
Soybean Yield ◽  
Agronomic Crops ◽  
Split Plot ◽  
Main Plot ◽  
Biomass Reduction

Abstract Velvetleaf is an economically important weed in agronomic crops in Nebraska and the United States. Dicamba applied alone usually does not provide complete velvetleaf control, particularly when velvetleaf is greater than 15 cm tall. The objectives of this experiment were to evaluate the interaction of dicamba, fluthiacet-methyl, and glyphosate applied alone or in a mixture in two- or three-way combinations for velvetleaf control in dicamba/glyphosate-resistant (DGR) soybean and to evaluate whether velvetleaf height (≤ 12 cm or ≤ 20 cm) at the time of herbicide application influences herbicide efficacy, velvetleaf density, biomass, and soybean yield. Field experiments were conducted near Clay Center, Nebraska in 2019 and 2020. The experiment was arranged in a split-plot with velvetleaf height (≤ 12 cm or ≤ 20 cm) as the main plot treatment and herbicides as sub-plot treatment. Fluthiacet provided ≥ 94% velvetleaf control 28 d after treatment (DAT) and ≥ 96% biomass reduction regardless of application rate or velvetleaf height. Velvetleaf control was 31% to 74% at 28 DAT when dicamba or glyphosate was applied alone to velvetleaf ≤ 20 cm tall compared with 47% to 100% control applied to ≤ 12 cm tall plants. Dicamba applied alone to ≤ 20 cm tall velvetleaf provided < 75% control and < 87% biomass reduction 28 DAT compared with ≥ 90% control with dicamba at 560 g ae ha−1 + fluthiacet at 7.2 g ai ha−1 or glyphosate at 1,260 g ae ha−1. Dicmaba at 280 g ae ha−1 + glyphosate at 630 g ae ha−1 applied to ≤ 20 cm tall velvetleaf resulted in 86% control 28 DAT compared with the expected 99% control. The interaction of dicamba + fluthiacet + glyphosate was additive for velvetleaf control and biomass reduction regardless of application rate and velvetleaf height.

Direct and Residual Effect of Planting Method and Phosphorous Levels on Productivity and Agro-Meteorological Indices, Thermal and Energy Efficiencies in Mungbean– Wheat Cropping System

2019 ◽  
Author(s):  
Parveen Kumar ◽  
Karmal Singh ◽  
K D Sharma ◽  
Anil Kumar ◽  
Amit Kumar
Keyword(s):  
Field Experiments ◽  
Residual Effect ◽  
Cropping System ◽  
Research Area ◽  
Yield Attributes ◽  
Planting Methods ◽  
Split Plot ◽  
Raised Bed ◽  
Planting Method ◽  
Plot Design

Field experiments were conducted for two consecutive years during kharif and rabi season of 2015-16 and 2016-17 at Research area, Department of Agronomy, CCSHAU, Hisar to evaluate the direct and residual effect of planting methods and phosphorus levels on productivity, agro-meteorological indices, thermal and energy efficiencies in mungbean– wheat cropping system. The experiment was laid out in split plot design during kharif and in split -split plot design during Rabi with five replications at same site during both the years. Main plot treatments consisted of planting methods viz. furrow irrigated raised bed (FIRB) and conventional where as sub plot consisted of three levels of phosphorus, viz., 30, 40 and 50 kg P2O5 /ha applied to mungbean in kharif and sub -sub treatments applied to wheat in rabi were 40, 50 and 60 kg P2O5 /ha. Sowing of mungbean and wheat crops on beds i.e. furrow irrigated raised bed was superior over conventional sowing in respect of productivity. In mungbean, application of 50 kg P2O5/ha to mungbean significantly increased grain yield over 30 and 40 kg P2O5/ha, respectively but it did not differ significantly with 40 kg P2O5/ha. The residual effect of phosphorous applied to mungbean was found to be non significant on yield attributes and yield of wheat. However, direct application of phosphorous to wheat had significant effect on yield attributes and yield. The agro meteorological indices values were similar under FIRB and conventional method however, thermal and energy efficiencies were higher under FIRB planting as compared to conventional and increased with increasing levels of phosphorous.

scholarly journals Лазерный комплекс с центральной длиной волны 1.55 μm для генерации импульсов с энергией более 1 μJ и суперконтинуума диапазоном около 2 октав

2019 ◽  
Vol 126 (6) ◽  
pp. 717
Author(s):  
Д.А. Столяров ◽  
Д.А. Коробко ◽  
И.О. Золотовский ◽  
А.А. Сысолятин
Keyword(s):  
Fiber Laser ◽  
Block Structure ◽  
Laser System ◽  
High Energy ◽  
Normal Dispersion ◽  
Highly Nonlinear Fiber ◽  
Highly Nonlinear ◽  
High Power Output ◽  
Output Amplifier ◽  
Simple Block

A fiber laser system of telecommunication range with simple block structure is considered. The main elements of the system are pulsed erbium fiber laser and several fiber amplifires. Including a fiber stretcher with a high normal dispersion the system works as a generator of high energy pulses. The characteristics of the high-power output amplifier and the pre-amplifiers are matched in such a way that the system is simply reconfigured into a supercontinuum source of the range from 600 to 2400 nm generated at the output of highly nonlinear fiber.

scholarly journals On a new approach to the analysis of variance for experiments with orthogonal block structure. IV. Experiments in split-plot designs

2020 ◽  
Vol 57 (2) ◽  
pp. 151-175
Author(s):  
Tadeusz Caliński ◽  
Agnieszka Łacka ◽  
Idzi Siatkowski
Keyword(s):  
Experimental Data ◽  
Hypothesis Testing ◽  
Analysis Of Variance ◽  
Block Structure ◽  
Practical Application ◽  
Simple Manner ◽  
New Approach ◽  
Testing Procedures ◽  
Split Plot

SummaryThis paper provides estimation and hypothesis testing procedures for experiments in split-plot designs. These experiments have been shown to have a convenient orthogonal block structure when properly randomized. Due to this property, the analysis of experimental data can be carried out in a relatively simple manner. Relevant simplification procedures are indicated. According to the adopted approach, the analysis of variance and hypothesis testing procedures can be performed directly, rather than by combining the results of analyses based on some stratum submodels. The practical application of the presented theory is illustrated by examples of real experiments in appropriate split-plot designs. The present paper is the fourth in the planned series of publications on the analysis of experiments with orthogonal block structure.

scholarly journals Etiology of Peanut Pod Rot in Nicaragua: I. The Effect of Pod Size, Calcium, Fungicide, and Nematicide

2010 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Joao Augusto ◽  
Timothy B. Brenneman ◽  
Alexander S. Csinos
Keyword(s):  
Field Experiments ◽  
Sclerotium Rolfsii ◽  
Calcium Content ◽  
Calcium Deficiency ◽  
Disease Etiology ◽  
Soil Calcium ◽  
Arachis Hypogaea L ◽  
The Pacific ◽  
Split Plot ◽  
Lesion Nematode

Pod rot is one of the most important peanut (Arachis hypogaea L.) diseases in the pacific coast region of Cosiguina in Nicaragua. The region receives excessive rainfall during the peanut growing season and fields with high pod rot incidence often have moderate to high infestations of stem rot (Sclerotium rolfsii) and lesion nematode (Pratylenchus spp.). It was hypothesized that soilborne fungi, nematode damage and/or soil calcium deficiency could be involved in peanut pod rot. Flutolanil (1.2 kg a.i./ha, two applications), aldicarb (3.4 kg a.i./ha, one application), and calcium (670 kg/ha, two applications of gypsum) were evaluated on small (Georgia Green) and large (C-99R) seeded, runner cultivars in field experiments from 2005 to 2007 to help determine disease etiology. Experiments were split-split-plot or split-plot designs and treatments were replicated five times. There were no differences in pod rot between the two cultivars. Flutolanil did not decrease pod rot and only increased yield when associated with aldicarb nematicide. Gypsum application did not decrease pod rot, or increase yield or pod calcium content. Aldicarb had no effect on pod rot, but significantly increased yield by 22%, apparently by suppression of pod and/or root damage by lesion nematode. Neither calcium deficiency nor lesion nematode damage increased pod rot. Accepted for publication 19 October 2009. Published 15 February 2010.

scholarly journals GD PBIBD(2)s in incomplete split-plot × split-block type experiments

2006 ◽  
Vol 3 (1) ◽  
Author(s):  
Katarzyna Ambroży ◽  
Iwona Mejza
Keyword(s):  
Block Structure ◽  
Block Design ◽  
Block Type ◽  
Block Designs ◽  
Balanced Incomplete Block Designs ◽  
Group Divisible ◽  
Split Plot ◽  
Randomization Scheme ◽  
Balanced Incomplete Block ◽  
Modeling Data

In this paper we present a method of designing a three-factor experiment with crossed and nested treatment structures. The design considered is called a split-plot × split-block design. A kind of design incomplete with respect to all three factors is examined. Additionally, we consider the usefulness of group divisible partially balanced incomplete block designs with two associate classes in planning such experiments. In modeling data obtained from them, we take into account the structure of experimental material and a four-step randomization scheme for the different kind of units. As regards the analysis of the obtained randomization model with seven strata, we adapt an approach typical of multistratum experiments with orthogonal block structure.

scholarly journals An Attempt to Evaluate the Effect of Varying Time Intervals Between Liming and Cropping on an Oxisol

1969 ◽  
Vol 65 (2) ◽  
pp. 83-89
Author(s):  
J. Badillo-Feliciano ◽  
M. A. Lugo-López
Keyword(s):  
Puerto Rico ◽  
Yield Components ◽  
Field Experiments ◽  
Time Interval ◽  
Time Intervals ◽  
Split Plot ◽  
Significant Yield ◽  
Field Beans ◽  
Plot Design

Field experiments were conducted on an Oxisol with pH 5.0 in northwestern Puerto Rico in an attempt to determine whether the time interval between liming and cropping affected yields, yield components, and other plant characters. Six lime-cropping interval treatments were tested with two cultivars of succeeding crops of field beans and corn in a split plot design. Two cultivars were used as indicator crops in each case. The liming-cropping intervals ranged from planting immediately after liming to planting 10 months after liming (liming on a bimonthly basis). No significant yield differences attributable to treatments could be detected for either crop. In the same fashion, no significant differences were obtained on the various yield components and plant characters studied except for the fact that the 27R fieldbeans from plots limed 10 months prior to planting were smaller than those from plots limed just before planting. The effectiveness of liming Oxisols with pH 5.0 seems not to depend on the time interval that elapses between liming and planting.

scholarly journals Sugarcane Production for 12-, 18-, and 24-Month Cycles Under Conditions in Puerto Rico

1969 ◽  
Vol 54 (1) ◽  
pp. 110-127
Author(s):  
S. Alers-Alers ◽  
M. A. Lugo-López ◽  
R. Gandía Caro
Keyword(s):  
Puerto Rico ◽  
Management Practices ◽  
Field Experiments ◽  
Crop Management ◽  
Total Sugar ◽  
Statistical Analyses ◽  
Sugarcane Production ◽  
Sugarcane Varieties ◽  
Split Plot ◽  
Plot Design

The data presented in this paper are from field experiments conducted at Corozal and Barceloneta following a split plot design where sugarcane cropping cycles or age at harvest (12-, 18-, and 24-month) were the main plots and varieties were the subplots. The varieties studied were: P.R. 1028, P.R. 1016, P.R. 1013, P.R. 980, P.R. 975 and B. 4362. Six replications were used. Statistical analyses of the data revealed that under the conditions prevailing in Puerto Rico, with the sugarcane varieties now available, and under typical current soil and crop management practices, 12- and 18-month canes are more efficient sugar producers than 24-month cane. More cane tonnage and more total sugar per acre per month were obtained during the short cycles than during the 24-month cycle.

Recent Developments in the design of field experiments. II. Unbalanced split-plot confounding

1946 ◽  
Vol 36 (1) ◽  
pp. 63-68 ◽  
Author(s):  
D. J Finney
Keyword(s):  
Research Council ◽  
Field Experiments ◽  
Agricultural Research ◽  
Balanced Design ◽  
Unbalanced Designs ◽  
Agricultural Research Council ◽  
Typical Experiment ◽  
Split Plot ◽  
Recent Developments ◽  
Simple Statistical Analysis

The device of split-plot confounding for introducing additional factors into a field experiment can only give a balanced design when the number of whole plots per block and the number of replications of each whole-plot treatment are multiples of the number of sub-sets into which the combinations of the additional factors are divided. When this condition is not satisfied it may still be possible to arrange that the design shall be partially or nearly balanced in such a way as to be useful in practice and to require a reasonably simple statistical analysis. Nevertheless, the experimenter should always bear in mind the desirability of balance, and should have recourse to unbalanced designs only when the exigencies of space or material, or an unforeseen necessity of introducing extra factors during the course of an experiment, leave him with no alternative. No attempt has been made to give a comprehensive account of designs of this kind, but the numerical analysis of the yields from a typical experiment has been discussed in detail. Though the lack of balance leads to some non-orthogonality of treatment contrasts, the more important comparisons can usually be satisfactorily estimated. The details of this estimation vary from one experiment to another, but the example given should make the principles clear to those who are familiar with the analysis of variance. I am indebted to Dr E. M. Crowther and to the Agricultural Research Council for permission to use the numerical results discussed in this paper

Some Design Problems in Crop Experimentation. I. The Use of Blocks

1995 ◽  
Vol 31 (2) ◽  
pp. 191-204 ◽  
Author(s):  
S. C. Pearce
Keyword(s):  
Analysis Of Variance ◽  
Field Experiments ◽  
Computer Programs ◽  
Design Problems ◽  
Modern Computer ◽  
Block Sizes

SUMMARYField experiments are commonly designed in blocks and there are sound reasons for using them, for example, control of unwanted environmental differences and administrative convenience. If used, they should be chosen to correspond to perceived differences in the site or to simplify farm operations and not merely to conform to statistical desiderata. Thus, it is not essential that each must contain one plot for each treatment, though there are advantages if they do. Some of the consequences of using other block sizes are examined, it being borne in mind that modern computer packages will perform most of the tiresome arithmetic. The effectiveness of blocks is considered and it is noted that they sometimes do harm rather than good. The analysis of variance is explained in terms of strata as used in many modern computer programs and is extended to include the recovery of information and resolvability. Recommendations are made as to randomization.

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