Carl S. Barfield

A Bioeconomic Simulation Approach to Multi-Species Insect Management

Classical approaches to the economics of pest management have focused almost exclusively on single-species models. This study develops and implements a methodology with which to evaluate multi-species, non-stochastic, managerial decisions subject to stochastic elements of the plant-insect system. Multi-species insect management strategies (combinations of scouting interval, threshold value, and choice of pesticide) are analyzed using a physiological mechanistic soybean plant growth model coupled to three insect population dynamics models. Preliminary results indicate that net returns are maximized and variance is reduced with lower thresholds and more frequent scouting than current recommendations.

Teaching as a Priority: A Promising Program at the University of Florida

Both supporters and critics of higher education express concern about the declining quality of teaching, particularly of undergraduates, within universities. Moreover, legislators in a dozen or more states are examining faculty workloads and developing legisla tion to ensure that faculty devote more of their time to teaching (Gilbert, Keck, and Simpson 1993; Winkler 1992). Although precise data about faculty teaching loads in the past are not available, the public perception that teaching loads have declined seems accurate. Winkler (1992) notes that the average teaching load in the 1920s and 1930s was thirteen to fourteen hours per semester as compared to an average load of 7.6 hours today. Like wise, Fairweather (1993) notes that self studies conducted at several large univer sities indicate that only one-fourth of all undergraduate courses are taught by full time university faculty. The public clearly is anxious about teaching in higher education, and similar discomfort exists within universities.

Major problems with evaluating multiple stress factors in agriculture

Abstract A major need for interdisciplinary IPM specialists has been access to methods for understanding the combined effects of multiple pests which, in nature, act simultaneously. Development of the Soybean Integrated Crop Management (SICM) model has potential for offering such a method. The physiologically‐based, validated soybean plant growth model at the core of SICM has provided a framework for coupling effects of multiple stresses at a process level. Combined stress effects from water and three insect species are presented in real economic context relative to soybean growers. The framework is now in place for adding stresses from weeds, foliar pathogens and nematodes. This approach offers insights into the experimental designs, analyses and potential uses of integrated pest management strategies developed by interdisciplinary scientists; yet, major problems exist in acquisition of model validation data. Conceptual and experimental dilemmas associated with these type efforts are outlined herein.

Programmed instructional materials for enhancing pest management teaching

Individualized instruction has been demonstrated to result in higher student comprehension and retention. There is a need in pest management training programmes for better quality visual materials which may take many forms. This paper reviews the development of a cadre of slide/text, slide, slide/tape, and computer aided pest management instructional materials currently in use at the University of Florida (USA) and the Pan American School of Agriculture (Honduras, Central America). The teaching philosophy under which they were developed, and problems with the media and their usage, are discussed.RésuméInstruction individuelle a demontré des resultats plus elevés de comprehension et retention par les ètudiants. Dans la lutte intégrée (IPM) il y a un besoin continu pour une meilleur qualité de materiéls visuels utilisés dans les programmes de formation. Ce document presente un cadre des differentes methodes (les diapositives, diapo/textes, television, imprimés, cassettes, et/ou lecture sur l’ordinateur) utilisés à la Universite de Florida (Etats-Unis) et la Escuela Agrícola Panamericana (Honduras). La philosophie d’enseignement donc lesquel ont etés developpés et les les problèmes associés sont aussi presentés.

Design and testing of Spanish language programmed instructional materials for plant protection

Abstract Several programmed instructional modules (for self‐paced and/or reinforced learning) in pest management were utilized at the Pan American School of Agriculture (Honduras) and the University of Guayaquil (Ecuador) within existing courses of plant protection. Three modes of delivery were employed: autotutorial, conventional lecture, and conventional lecture + slide illustration. Student performance, as measured by the percentage differences between pre‐and post‐module examination, were determined, and significant differences did occur among modules and among modes of presentation. Up to a 41% drop in the standard error of post‐instruction (v. pre‐instruction) test scores occurred, indicating our modules had a ‘standardizing’ effect on student users. The utility of programmed instructional learning in the developing world and on the need to tailor ‘mode of delivery’ to the subject being taught are discussed.