Statistical design and analysis for intercropping experiments. Volume I: Two crops
This is the first of two volumes on statistical design and analysis of data for intercropping experiments. Intercropping here refers to the growing of two or more crops sequentially or concurrently on the same area of land. This volume deals with those situations in which we have mixtures of two crops and/or the individual (sole) crops while Volume II (to be published in the near future) will generalize to the situations having mixtures (intercrops) of more than two crops. The contents of Volume I are covered in 10 chapters, and the author has taken great care to present concepts and ideas in an order of increasing difficulty. After presenting in Chapter 1 some basic concepts and definitions together with other preliminary ideas, Chapter 2 deals with the situation in which there is one main and one supplementary crop. The situations when both crops are main crops and to analyze the individual crop responses are considered in Chapter 3. Both crops are considered to be main crops again in Chapter 4 but here a combined response for the yields of both the crops is required. This necessitates to create more variables as in a multivariate analysis. The objective in this chapter is to illustrate a number of approaches to analyzing data from intercropping experiments. The density of crops in all these chapters is held to be constant. Chapter 5 deals with those situations in which the density of crops is no longer held constant but is treated as a variable for both the crops, and the response is assumed to be a function of density. In the next chapter the responses are modeled in the same way as they are done for diallel crossing systems with the exception that responses are available for each member of the mixture. The material presented in Chapter 7 is closer to the ordinary diallel crossing situation, and deals with intercropping experiments for which individual crop responses are not available and there is only one response for the mixture for each variable measured. Chapter 8 deals with those intercropping experiments in which spatial arrangements of two crops are considered. Here designs with various spatial and density arrangements are considered, and a statistical analysis is suggested for some. The next chapter deals with analyses for replacement series experiments (those in which the ratio of one crop to a second varies from 0 to 1), and a linear programming approach towards the optimum use of land is demonstrated. A number of indices (such as relative crowding coefficient, the competitive ratio index, a coefficient for total effective area, etc., etc.) are presented and discussed. The last chapter includes design concepts and experiment designs which are of use to intercropping experiments. All the designs presented through Chapter 9 are treatment designs which deal with the selection of treatments as well as points of reference (such as controls, etc., etc.) to be used in the experiment whereas material presented in the last chapter is concerned with the arrangement of treatments in an investigation. Every chapter ends with a useful list of references, includes a set of problems, and a comprehensive summary and discussion. For practitioners and researchers not interested in mathematical proofs, some such derivations are given in the appendixes at the end of each chapter. An index is included. There are some minor misprints which can be easily detected. This book is well-written, and the material has been presented with great clarity. The author has done a commendable job in presenting concepts and ideas for intercropping experiments in an easy-to-understand style. It is going to be of great value to students and researchers in various disciplines such as biometry, ecology, agriculture, etc., etc. The author is known for his significant contributions to design of experiments, and the reader will find the present volume to be a work of attractive format, careful scholarship, and very informative on intercropping experiments. A welcome and useful addition to the statistical literature.
scientific article; zbMATH DE number 410738