Physical Sciences and Mathematics Commons^™

Distance Measures In Post Hoc Comparisons Of Temperature Germination Quadratic Response Surfaces, D. E. Palmquist, S. N. Bagchi, J. A. Young, R. D. Davis

Conference on Applied Statistics in Agriculture

Generalized quadratic response surface models are used to describe seed germination at diurnally alternating cold and warm incubation temperatures for three Great Basin exotic plant species. The method of the F-statistic SS_drop is applied to determine whether the response surface models are equal. Two proposed distance measures are used as modified multiple comparison techniques for determining differences between surfaces. These measures prove useful in distinguishing between the species showing the highest germination response and the one showing the lowest response to the incubation temperature ranges studied.

Tools For The Construction Of Effective Experimental Designs, M. F. Franklin, R. W. Payne

Conference on Applied Statistics in Agriculture

Experimenters should be able to choose between competing designs the one which yields the required information clearly and efficiently at the desired precision. One way to achieve this is to allow interaction between design and analysis but few statistical analysis packages include more than rudimentary design facilities. We review some of the theory and tools for design construction with a view to providing the statistician and experimenter with a tool-kit for building the most effective design. Examples in the design process are techniques for determining aliases and patterns of confounding, algorithms for constructing fractional factorial and incomplete block designs and …

Confidence Intervals For Variance Components In One-Way Unbalanced Designs, Franklin A. Graybill, Rana S. Fayyad

Conference on Applied Statistics in Agriculture

Consider the one way unbalanced components of variance model given by Y_ij = μ + A_i + E_ij, (i = l, ... ,a, j = l, ... ,b_i) where μ is an unknown constant parameter, A_i and E_ij are independent normal random variables with zero means and variances σ²_A and σ²_E respectively,

The problem is to obtain a confidence interval for σ²_A with confidence coefficient greater than or equal to a specified 1 - α. Three new procedures for obtaining confidence intervals for σ²_{A …}

Editor's Preface, Table Of Contents, And List Of Attendees, William Noble

Conference on Applied Statistics in Agriculture

These proceedings contain papers presented in the fifth annual Kansas State University Conference on Applied Statistics in Agriculture, held in Manhattan, Kansas, April 25 through 27, 1993.

Producing And Marketing Kentucky Hay - A Challenge, Ed Logsdon

Kentucky Alfalfa and Stored Forage Conference

Many of you probably are aware that Kentucky's commodity organizations are working with UK, the Agriculture Department and Farm Bureau in developing a plan to improve farm income in the state. This is a very ambitious project involving more than 40 farm organizations, including the Kentucky Forage and Grassland Council. This group has set a lofty goal of attempting to raise gross farm sales in the state from its current $3 billion level to around $5 billion by the turn of the century.

Alfalfa For Hay And Grazing In Tennessee, Joe Burns

Kentucky Alfalfa and Stored Forage Conference

Alfalfa has truly had its "ups and downs" in terms of acreage in Tennessee for the last 30 years. Just as the effect of a good fertilizer-lime-soil testing program was increasing the alfalfa acreage, the alfalfa weevil appears and begins to destroy the crop. With the aid of the insecticide heptachlor sprayed on the fertilizer, farmers continued to fertilize the alfalfa and kill the weevil at the same time.

Grazing Alfalfa — National Perspective, Warren C. Thompson

Kentucky Alfalfa and Stored Forage Conference

The production of alfalfa specifically for grazing is a fairly new practice. But now, farmers all around the USA are beginning to look toward alfalfa for a long living legume to increase yield, quality, and reliability all during the growing and grazing seasons. They also are looking for ways to reduce the cost of harvest, equipment, and storage costs, as well as weather-related harvest losses, and in time, reduced fertilizer costs.

Grazing Alfalfa — State Perspective, W. Roy Burris, Garry D. Lacefield

Kentucky Alfalfa and Stored Forage Conference

Alfalfa has been grown in Kentucky for many years, but in the last decade, its acreage has increased dramatically- from 208,000 in 1978 to 350,000 in 1981 (Ky. Agri. Statistics Service). Alfalfa is generally thought of as a hay crop but the practice of grazing alfalfa has received considerable attention recently. Much of this interest was generated by "Graze-More-Beef" demonstrations which have been conducted in the state. Demonstrations in which alfalfa was grazed averaged 791 pounds per acre during 1986-1988. Alfalfa's ability to withstand dry weather and its excellent nutritional qualities make it an attractive grazing alternative to fescue - …

Do's And Don'ts Of Alfalfa Grazing, Ken Johnson

Kentucky Alfalfa and Stored Forage Conference

I usually start grazing in April when alfalfa is about 10 inches tall. I like to start with enough cattle to graze a paddock clean in two to five days, then move to another paddock, returning to re-graze in about 35 days. I usually need at least eight paddocks in the system. You must rotate cattle on Alfalfa for the stand to persist. It will take seven or eight head of 500 pound calves per acre to keep up with alfalfa growth in the spring. Part of the calves will need to be removed in June and maybe some more …

Grazing Alfalfa — County Perspective, Steve Osborne

Kentucky Alfalfa and Stored Forage Conference

Often the difference between successful farming operations and others is the ability of the producers to manage the available resources to their advantage. The rolling topography and plentiful supply of livestock water in Monroe County is well suited to forage production. The purpose of this program is to introduce new forage species, improve forage production, and increase producer profits.

Grazing Alfalfa — An Overview, Garry D. Lacefield, W. Roy Burris

Kentucky Alfalfa and Stored Forage Conference

Alfalfa is the most important forage legume grown in the United States. Grown over a wide range of soil and climatic conditions it has the highest yield potential and feeding value of all perennial forage legumes. This versatile crop can be used for hay, pasture, silage, green-chop, pellets, cubes and soil improvement. Because of its many merits, especially yield, quality and versatility, it can be used successfully in many animal feeding programs.

Grazing alfalfa has not been practiced to any great extent in the U.S., but has been done extensively in other countries. Research and producer experience has shown excellent …

Quality From The Seed To The Sale To The Animal, Jimmy C. Henning, Garry D. Lacefield

Kentucky Alfalfa and Stored Forage Conference

Forages in Kentucky have been valued at over $700 million annually. This figure combines receipts from cash hay sales to indirect value from the portion of beef, dairy, sheep, and horse receipts that are attributable to pasture and stored forages. However, the key to the maintaining and even increasing the value of forages to Kentucky lies in Quality: A) Quality of seed B) Quality as it relates to sales, and C) Quality as it relates to the animal.

New Developments In Hay Harvesting, Michael Collins

Kentucky Alfalfa and Stored Forage Conference

Hay and pasture crops are critical to Kentucky Agriculture and to that of the entire temperate region of the US. The sale of cattle, calves and dairy products provide 29% of Kentucky's farm income compared with 23% for tobacco. Beef cowcalf enterprises comprise the majority of cattle numbers in the state, however, dairy production is also significant. A substantial horse industry also exists in Kentucky which is an excellent market for high quality alfalfa hay. At present a substantial amount of alfalfa for feeding horses in the state is imported.

My Observations And Experiences With Alfalfa, Larry Jeffries

Kentucky Alfalfa and Stored Forage Conference

I was raised on a small dairy farm in Henry County, Kentucky. I'm the oldest of six children and wanted to leave the farm as soon as possible. Upon graduation from Transylvania College in 1956, I was quickly drafted into the U.S. Army. I was sent to El Paso, Texas, for training and remained in the southwest for 11 (eleven) years.

In 1958 I married Carolyn Billman. We have 4 (four) children: Rae Lynne, Janet, Keith, and Joy.

Upon returning home to Henry County to farm and teach school in 1967, I found a catastrophe had happened to the alfalfa …

An Alfalfa Management Program For Optimum Yields And Quality, Bill Griffith

Kentucky Alfalfa and Stored Forage Conference

Alfalfa popularity is not surprising because it has the highest yield potential and the highest feeding value of all perennial hay crops. While the protein value of alfalfa is of major importance, its energy content is also high and should not be discounted. High yields of alfalfa harvested at the proper stage of maturity compare favorably with corn silage in production of energy.

Alfalfa Production And Trends In Kentucky, David D. Williamson

Kentucky Alfalfa and Stored Forage Conference

Alfalfa is often referred to as the "Queen of U.S. Forage Production". Looking at all hay production alfalfa should be called "The King". In 1991, 83.8 million tons were harvested in the United States -- 55 percent of all the hay harvested in the United States. This total does not include the many tons harvested as green chop, which is an especially common practice among dairy farmers. But, why shouldn't alfalfa be popular? This deep rooted leguminous plant is generally the forage leader in yield, protein, and TDN.

Foreword [1993], Garry D. Lacefield

Kentucky Alfalfa and Stored Forage Conference

This is the front matter of the proceedings.

Bill #92-09-F - Contractual Agreement For Adopt-A-Spot Program, Wku Student Government Association

Student Government Association

Bill regarding Adopt-a-Spot litter program on Western Kentucky University campus.

The Need For The Analysis Of Treatment X Period Interaction In Animal Experiments, L. A. Goonewardene, L. Z. Florence

Conference on Applied Statistics in Agriculture

Many growth experiments, in which weights are taken at different times on the same animals, involve the comparison of factorial main effects and interactions but exclude time (period) as an effect. The objective of this paper is to show that more information can be obtained by analysing the data as a repeated measures design. As an example, feedlot cattle being prepared for market are often on growth implants and provided different diets depending on the stage of growth and maturity. Growth promoting implants, either single or double, may be slow or fast acting. During the growing period, a diet with …

A Comparison Of Double Sampling Regression Estimators, Dennis L. Clason, G. Morris Southward

Conference on Applied Statistics in Agriculture

We investigate three alternative models for estimating the mean of a population using double sampling survey techniques. One estimator was found in the range science literature (Cook and Stubbendieck, 1986), another is the estimator presented by Cochran (1977). The third estimator uses method-of-moments estimators with measurement error regression models. Simulation studies suggest that the measurement error model does not work well when the slope is appreciably different from unity. Delta method variance estimators of the measurement error model may give negative variance estimates under these circumstances. The other estimators have better small sample performance (both are approximately unbiased, and have …

Simplified Data Analysis For Generally Balanced But Messy Experimental Designs, Richard E. Lund

Conference on Applied Statistics in Agriculture

Johnson posted the essential elements of a 'messy' experimental design and challenged participants at the 1991 KSU Conference on Applied Statistics in Agriculture to provide an analysis. Subsequently, he proposed an analysis using SAS. The experiment was laid out by a soil scientist and involved six classifying factors in an intricate crossing and nesting arrangement which lead to a need to consider eight error terms. My objective at the poster session was to show by live computer demonstration that the analysis can be setup and conducted more easily by use of software applying Wilkinson's methodology.

Soil Properties And Landtypes--Classification And Identification With Discriminant Analysis, R. David Hammer, John W. Philpot

Conference on Applied Statistics in Agriculture

Intensive land use is requiring more detailed information about patterns and magnitudes of soil variability than can be acquired through traditional soil survey techniques. Discriminant analysis is a mathematical method of numerical classification which could be used to identify discrete populations of soils in their natural settings. The hypothesis of this study was that discriminant analysis could be used to group soils on landtypes on the Mid-Cumberland Plateau. A large data set (132 observations of 29 soil variables) was collected from three landtypes at two Cumberland Plateau locations. Discriminant analysis was used to classify the soil observations into landtypes. Canonical …

Regression Modeling Using Principal Components, Shahar Boneh, Gonzalo R. Mendieta

Conference on Applied Statistics in Agriculture

In this paper we present a new stepwise method for selecting predictor variables in linear regression models and its application to agricultural data analysis. This method is an extension of principal component regression, and it consists of iteratively selecting original predictor variables one at a time from repeatedly selected subsets of principal components. The reasoning behind the method and its implementation are discussed, and an example of applying the method to agricultural data is given. The example also demonstrates the advantages of the proposed method over some known methods.

An Example Of Path Analysis Applied To Classification Variables Applied To Classification Variables, Richard E. Lund, Albert L. Scharen

Conference on Applied Statistics in Agriculture

Path analysis was originally proposed to decompose and interpret causal linear relationships among a set of continuous stochastic variables. Research designs necessarily employed the natural variation in the system rather than the technique of controlling independent variables by selection of levels and categories which is emphasized in many experimental designs. Path coefficients are closely related to correlation coefficients, the size of which will be controlled when variation in the system is controlled. We examine a data set produced by research related to worldwide occurrence of a wheat pathogen and describe techniques for applying path analysis to its variables, some of …

When Should Random Effects Be Included In Estimable Functions And When They Should Not?, David C. Blouin

Conference on Applied Statistics in Agriculture

In the mixed model, the behavior of linear functions of the fixed and random effects is examined. It is found that inclusion of certain functions of random effects can lead to estimators which are equivalent to those under a fixed effects model and are inconsistent with the inherent structure of the mixed model. Three examples are presented which illustrate the behavior of linear functions of the fixed and random effects. These functions represent the broad, narrow and intermediate inference spaces as introduced by McLean, Sanders and Stroup (1991). Which random effects should be included in the model is discussed. Random …

Analyzing Split-Plot Andrepeated-Measures Designsusing Mixed Models, Russ Wolfinger, Nancy Miles-Mcdermott, Jenny Kendall

Conference on Applied Statistics in Agriculture

We first introduce the general linear mixed model and provide a justification for using REML to fit it. Then, for an irrigation example, we present several mixed models of increasing complexity. The initial model corresponds to a typical split-plot analysis. Next, we present covariance structures that directly describe the variability of repeated measures within whole plots. Finally, we combine the above types into more complicated mixed models, and compare them using likelihood-based criteria.

Analysis Of Mixed Models Without Mixed Models Software, George A. Milliken

Conference on Applied Statistics in Agriculture

The recent development of mixed model software has expanded the use of mixed models analysis, but mixed models have been analyzed using non-mixed models software for many years. The purpose of this paper is to discuss the differences, similarities, advantages and disadvantages of the two approaches. Section 1 introduces the mixed model with two examples. The analysis of the mixed model using mixed models software is presented in Section 2 and the analysis of the mixed model using non-mixed models software is described in Section 3. Finally, an 'example' is used to compare the two methodologies.

Options For Analyzing Unbalanced Split-Plot Experiments: A Case Study, Marta D. Remmenga, Dallas E. Johnson

Conference on Applied Statistics in Agriculture

Unbalanced split-plot experiments present many analysis problems. This paper discusses some of the difficulties by comparing the results of the analysis recommended by Milliken and Johnson (1984) to a set of minimal sufficient statistics using a small experiment from Milliken and Johnson as a case study. The estimators used by Milliken and Johnson are not necessarily the best (smallest variance) estimators. A set of minimal sufficient statistics is used to show that the whole plot error term suggested by Milliken and Johnson does not have a distribution that is proportional to an exact chi-square distribution and is not always independent …

The Analysis Of Tree Ring Chronologies Using A Mixed Linear Model, O. Brian Allen, Daniel A.J. Ryan, David L. Mclaughlin

Conference on Applied Statistics in Agriculture

The analysis of a tree's annual growth rings can provide a great deal of information about the environment in which the tree has grown. In this paper we propose statistical methodology for analysing the incremental growth of sugar maple sampled throughout southern and central Ontario, by the Ontario Ministry of the Environment. Two trees, ranging in age from 75 to 150 years, were sampled from each of 42 stands in 6 regions. The data were analysed using a mixed linear model, incorporating age of tree, region, year, a year by region interaction and average monthly air temperature and total seasonal …

Estimating Variance Functions For Weighted Linear Regression, Michael S. Williams, Hans T. Schreuder, Timothy G. Gregoire, William A. Bechtold

Conference on Applied Statistics in Agriculture

For linear models with heterogeneous error structure, four variance function models are examined for predicting the error structure in two loblolly pine data sets and one white oak data set. An index of fit and a simulation study were used to determine which models were best. The size of coefficients for linear and higher order terms varied drastically across different data sets, thus it is not desirable to recommend a general model containing both linear and higher order terms. The unspecified exponent model σ²v_i = σ²⁽D_i² H_i)^{k 1} is recommended …