Written in Spanish, this manual, which deals with traditional field crops, is primarily designed to help Peace Corps volunteers develop and strengthen their agricultural skills. The focus of the manual is on surveying and interpreting local agricultural environment and individual farm units, developing agricultural extension techniques and practices, and providing basic hands-on and technical skills for extension workers in operations from farm land preparation through harvest. Covered in the individual chapters of the guide are the agricultural environment; reference crops; planning and preparation; soil fertility and management; pest and disease control; and harvesting, drying, and storage of crops. Appendixes to the manual include a list of common units of measurement and conversion; guidelines for conducting field trial result tests and demonstration plots, structural analysis, and soil samples; directions for using pesticides and herbicides; suggestions for troubleshooting common crop problems; lists of hunger signs in reference crops; and a discussion of planting skills for field extension workers. Concluding the manual are a glossary, a four-page bibliography, and a list of six references. (CML)