The objectives of this report are three-fold. Firstly, it is planned to review briefly the work conducted by the CIMMYT wheat physiology/agronomy program since its inception 5 years ago and the conclusions forthcoming. The second portion of the report will discuss the application of these research results, and in the final part recommendations will be made regarding the future of wheat physiology in CIMMYT. The purpose of the physiology/agronomy program was, on the physiological side, to assist the breeding programs in the efforts to further increase yield, and on the agronomic side, to continue production research initiated by Dr. R. Laird and aiming to determine the package of agronomic practices for the new genotypes being produced by the breeders. A broad interpretation was put on the first aim, so ai to include fairly basic crop physiological work directed towards understanding the physiology of yield in wheat. This was justified on the grounds that virtually no crop physiological work had been done on wheat in low latitude environments. At the same time the effort was initially restricted to irrigated wheat in the winter crop cycle in northwest Mexico. This is an environment fairly representative of many parts of the developing world where irrigated wheat is widely grown (India, Pakistan, southern China, Egypt, Sudan), and it was a case of doing one thing at a time. Thus much of the research was carried out on the CIANO research station. The general philosophy was that the physiological research must begin in the field and work back towards the laboratory if and when necessary. This is why it is referred to as crop physiological rather than plant physiological research. Also, emphasis was put upon simple techniques, partly because of the obvious need to study many more genotypes than had ever been studied before, and partly because of maintenance problems with sophisticated equipment. On the agronomic side, work was restricted initially to fairly defined conditions on the experiment station. As soon as it became obvious that interactions between new genotypes and agronomic practices were not going to be as great as had been seen in the past, attention in wheat agronomy turned towards several new areas and direction of the effort passed largely to Dr. M. McMahon. The physiology/agronomy program started in mid 1970 with a leader (RAF), one research assistant and one field assistant. It grew in early 1973 with the arrival of two post-doctoral scientists (Ors. D. HilleRislambers and M. McMahon). Later that year Dr. McMahon took over most of the agronomic research. Physiology grew again In 1974 with the appointment of a second field assistant. Early in 1975 Dr. HllleRislambers left to take a position with IRRI being replaced in March 1975 by Mr. P.C. Wall, a predoctoral scientist. Upon my departure the section will comprise Mr. Wall and one field assistant, with vacancies which arose recently for a research assistant and a field assistant. A considerable portion of the research carried-out has been done by graduate students (two M.Sc. students from National Agricultural University at Chapingo, and one Ph.D. student each from the Universities of California, Cornell and Reading). In addition several visiting scientists have assisted in certain projects to the extent of about 1 man year. Finally trainees from the production training program carried out several of the more agronomic experiments. Huch of the research has been documented in the duplicated reports prepared each year by wheat physiology and production training. Some of it has been published and some has recently been submitted for publication. Copies of most these materials are to be found in the Appendix. In addition the CIMMYT annual reports carry brief seminaries of the wheat physiology research. On the other hand much remains to be published, although it is anticipated that this task will be largely completed in the next 12 months.183 pages