This audiotutorial unit (cassette, printed script, 140 color slides, study guide, self-evaluation test), prepared by the Communication Support Unit at CIAT, is available for use with a manually or automatically synchronized slide projector/cassette tape recorder. Each unit is available from the Distribution Office at a cost of US$50; photocopies of the study guide alone can be obtained from the Bean Information Center.

Information on some diseases and pests that attack cassava, as well as the symptoms induced by nutritional deficiencies and toxicities and damage resulting from the misuse of herbicides are given in this manual. Specific and general recommendations regarding the control of the described problems are included. Disease control on a commercial scale is discussed. Formulae suggested for stake treatment before planting and storage and a key for identifying some cassava diseases are annexed. Color photos on symtomatology are included. (AS)

Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa.

Digital soil mapping (DSM) permits continuous mapping soil types and properties through raster formats considering variation within soil class, in contrast to the traditional mapping that only considers spatial variation of soils at the boundaries of delineated polygons. The objective of this study was to compare the performance of SoLIM (Soil Land Inference Model) for two sets of environmental variables on digital mapping of saturated hydraulic conductivity and solum depth (A + B horizons) and to apply the best model on runoff risk evaluation.

Anthropological work carried out by the PROFRIZA project in Cusco over 2 cropping seasons, between 1988-90, are reported. The status of bean cultivation in the region was assessed, as well as the experience acquired in seed production, small farmer management of farming activities, and the integration of farming communities that have old ways of exchanging products and services. Appropriate technology to promote crop improvement was identified, and crop management aimed at achieving good results on just one field, instead of several fields, and perhaps with low yields.