||The use of multiline varieties, described elsewhere in this report, offers one excellent option for slowing down the build-up of a rust epidemic and thereby permits the crop to mature without damage. The writer and his Mexican colleagues developed two tall strawed multiline wheat varieties and demonstrated their potential usefulness in the control of rust more than 20 years ago. Unfortunately, elaboration of these multilines coincided with the development and release of the higher yielding dwarf wheat varieties, and as a consequence, the multiline varieties were not released. During the 1960's and early 1970's most of the breeding research emphasis at CIMMYT was concentrated on correcting the defects in the early dwarf varieties e.g. broadening disease resistance, improving straw strength and milling and baking properties, etc. Within the last six years, a modest research effort has been made to develop iso-lines of the 8156 varieties Kalyansona and Siete Cerros that are potential candidates for use in multiline varieties being developed by a number of national wheat programs. Today, as I read through and write the introduction to this annual report, which is the last that I will issue while I am director of the CIMMYT wheat program, I cannot help but reflect on the great progress that has been made in developing an effective cooperative system of international testing of genetic materials in wheat, barley and triticale. Three decades ago, there was no international testing. Today, there is a worldwide international fraternity of collaborating wheat scientists who cooperate with each other for mutual benefits as well as for collective benefits. In this report our staff has assembled a summary of the recent cooperative efforts and results in research and production programs of hundreds of scientists from many countries. In 1978, our international nurseries of bread wheat, durum wheat, barley and triticale were shipped to 108 countries. These nurseries put new germ plasm on display and generate testing data to guide the worldwide wheat network in further breeding.