Many people have contributed to the ideas and techniques discussed in this guide. These include the hundreds of farmers, traders and extension officers who it has been my privilege to work with during the last 25 years. Ed Seidler, Andrew Shepherd and Åke Olofsson of FAO, Andrew Sergeant and Peter Jaeger of Accord Associates LLP, Steven Harris of TechnoServe, Alex Serrano of CLUSA, Lulama Ntshephe of the Department of Agriculture, South Africa, Sanjay Gupta of MART, Janet Kent and Allison Brown, have all made important inputs that have added enormously to the book. Particular thanks are extended to Andrew Shepherd for his extensive restructuring and editing of the text and to Francesca Cabre-Aguilar for her patient secretarial support. Design was carried out by Tom Laughlin and Fabio Ricci and last, but certainly not least, cartoons have been provided by Yuss.