Based on a British Mycological Society symposium held in September 1988, this book provides a timely review of the increasingly diverse ways in which fungi are being used to improve plant growth and examines the reasons for the rapid advancement in their commercialisation. Reflecting the increasing interest in biocontrol, a significant proportion of the book considers fungi as biocontrol agents, examining their specific use in the control of weeds, parasitic insects and nematodes, and plant pathogenic fungi, as well as covering more general commercial and environmental aspects. Relevant techniques in molecular biology are described and their possible application in this area examined. Chapters on the use of mutualistically symbiotic mycorrhizal fungi for the improvement of plant growth are also included.