Briscoe B.C. Field Trials Manual for Multipurpose Tree Species

Winrock International Institute for Agricultural Development, 1989. — 160 p.All research plans share the following essential elements: statement of objectives; background; treatment specifications; proposed method of analysis. The statement of objectives should be clear and concise and should assign relative priorities. It should also clearly define the population to be studied to help guide experimental design. When appropriate, it should briefly explain the Importance of the study.
Background should include the reasons why the objectives are Important and a summary of related work.
Treatments (procedures or materials whose effects are to be measured) must be stated clearly and in detail, and their relation to the objectives must be understood. Preferred treatments are those that Indicate basic relations: nitrogen fixing versus non-nitrogen fixing, tolerant versus Intolerant species, etc.
Any series of treatments may include a control (either a treatment found usually to give good results or no treatment at all). The control treatment must be randomized, replicated, and dealt with like other treatments. A no-treatment control is used particularly with applications of fertilizers or herbicides. Other specifications usually include number of replications, plot size, season of treatment, general management practices applied to all treatments, and details on required equipment and materials.
Personnel and their individual responsibilities should also be specified.
Method of analysis Is Included as an important guide to experimental design. Commonly included are a sample form for summarizing results, a model of analysis of variance or covarlance, and/or the primary form of equation to be used for regression analysis
What This Manual Is About
The Field Trials Manual for Multipurpose Tree Species is designed to help guide MPTS field researchers, whether for forestry or agroforestry objectives. In this context, the term forestry refers to the management of trees in groups for producing goods and services; agroforestry refers to production systems in which woody perennials interact with agricultural crops and/or animals for producing goods and services. This manual Is not a comprehensive treatise on field-trial procedures.
Its objective is to describe a system with a high reliability in the field, based on standard field methods and simple designs.
Section 2.0 reviews basic considerations in designing a statistically valid trial. Some examples, with possible field layouts, are Included. Section 3.0 treats nursery practices, including germination of seeds, care of seedlings, lifting and transport. It does not discuss nursery location, establishment, or management. Field establishment and post-planting care (sections 4.0 and 5.0, respectively) describe what should be done but not how. The "how" depends greatly on local tools and practices, most of which are satisfactory if care is used.
Measurements (section 6.0) are considered in detail because they must be standardized to ensure meaningful comparisons between experiments, even those conducted by the same scientist.
Details given for recording data in section 7.0 are applicable only to the Information and Decision Support System (IADSS) prepared by the F/FRED Global Research Unit. The type of information is virtually universal to MPTS studies.
The specific forms described in section 7.0 are contained in the IADSS software (version 1.1). A final version of the summary forms is awaiting agreement by scientists in other networks and will be included in a future edition of this manual.
Both the software and documentation will be available to research organizations in developing countries.
The codes contained in section 8.0 are provided to reduce the tedious detail of data entry, conserve computer memory, and speed analysis.
The appendices include field trial procedures already under way in the F/FRED-sponsored humid and sub-humid network and those planned for arid and semi-arid network trials. Because procedures logically will differ between networks, those Included here should be considered as examples, but not necessarily models.
This manual emphasizes the need for standardized methodology. This does not imply that scientists should conduct identical experiments. It means that they should determine and express site and tree characteristics in the same way so that variations represent experimental, not methodological, differences.
Who Should Use This Manual
The Field Trials Manual for Multipurpose Tree Species has been prepared for the research cooperators of the MPTS network sponsored by the F/FRED Project. However, we hope that, with periodic updates, this manual can aid any scientist Interested in establishing and measuring field experiments of MPTS.
We also hope scientists will review the procedures contained in this manual and recommend changes and improvements. By early 1990, it should be possible to publish an updated version that describes an effective, fully integrated, and proven system for field trial establishment, care, measurement, and analysis. Thereafter, scientists and research organizations can confidently exchange and compare information from the summary forms.1.0 Introduction
2.0 Design of Experiments
2.1 Range of conditions to be tested
2.2 Simplicity
2.3 Randomization
2.4 Replication
2.5 Records
3.0 Nursery Procedures
3.1 Introduction
3.2 Seed treatment
3.3 Containers and beds
3.4 Culture
3.5 Protection
3.6 Grading stock
3.7 Lifting and transport
4.0 Establishment
4.1 Plot size
4.2 Site preparation
4.3 Spacing
4.4 Sowing
4.5 Planting
5.0 Post-Planting Care
5.1 Cleaning and weeding
5.2 Pruning and lopping
5.3 Pollarding and coppicing
5.4 Thinning and stand improvement
5.5 Harvest
6.0 Measurements
6.1 Traditional forestry measurements
6.1.1 Height
6.1.2 Diameter of the tree stem
6.1.3 Multiple stems
6.1.4 Specific gravity
6.2 Non-traditional measurements
6.2.1 Total height
6.2.2 Stem length
6.2.3 Diameter
6.2.4 Wood volume
6.2.5 Extractives
6.2.6 Fodder
6.2.7 Intercrop yield
6.2.8 Animal production
6.3 Re-measurements
6.4 Modeling
7.0 Record Forms for the Information and Decision Support System 79 (7.1-7.31, see pp. 6-7)
7.32 Research summary database
8.0 IADSS Codes
8.1 Country codes
8.2 Network trials Institution codes
8.3 Species codes
8.4 Standard symbols
8.5 Silvicultural treatments
Appendices
A Humid and sub-humid zone
Arid zone
Semi-arid zone
For further reading
Index