||Worldwide interest has been shown in the man-made crop plant called Triticale, a plant produced by crossing wheat and rye. Initially a biological oddity, Triticale has now reached the stage of having potential commercial capabilities. Due primarily to the work of members of the Plant Science Department of the University of Manitoba, and, more recently to CIMMYT working in collaboration with the Canadian group, many of the basic deficiencies of Triticale are being overcome. By improving the growth habit, plant type, disease resistance and fertility, the productivity of Triticale now warrants testing over a much wider range of environments. The International Triticale Yield Nursery was initiated to serve a number of different purposes, namely: 1) to provide the research workers developing commercial varieties of Triticale an opportunity to assess the performance and adaptation of their advanced breeding lines over a wide range of latitudes, climates, day lengths, fertility conditions, water management and disease complexes; 2) to allow cereal workers in other countries to assess and compare the potential of this new crop plant with existing cereals grown in their own country; and 3) to stimulate the interchange of improved germplasm of Triticale and thus hasten its development as a commercial crop plant. The first yield nurseries have been designed to assess the performance of advanced breeding lines and to compare them to other types of wheat. The performance of the Triticale lines may be disappointing in some environments at first, but rapid progress is being made and the information gained from the yield nurseries will be invaluable to guide the breeders in their search for improved germplasm. It is understood that any country collaborating in these tests will be free to use any of the material included in the nursery, either as parental material or as commercial varieties. In this latter case, the country of origin of the variety or line under multiplication should be recognized. We sincerely request the cooperation of all persons or institutions interested in this test. It is a collective endeavor and its success depends upon what is collectively contributed to its improvement. We realize that it may have faults and limitations and would appreciate any suggestions for its improvement.