This group, which is concerned with the applications of mathematics to agricultural science, is sponsored by the Agricultural and Food Research Council. It was formed in 1970, and has since met at approximately yearly intervals in London for one-day meetings. The twenty-second meeting of the group, chaired by Professor J. M. Forbes of the Department of Animal Physiology and Nutrition at the University of Leeds, was held in the Wellcome Meeting Room at the Royal Society, 6 Carlton House Terrace, London on Friday, 10 April 1992, when the following papers were read.