| Abstract |
Wheat production continued to expand faster than population growth, both world wide and in the developing countries. In the past decade, wheat production rose 50 per cent and population 30 per cent. World wheat production in 1976 reached a new record of 413.3 million metric tons. In the developing countries, production also set a new record of 80.5 million metric tons. Algeria, India, Iran, Pakistan and Tunisia made noteworthy large production increases. However despite this progress, developing countries continue to import more than 20 million metric tons of wheat and wheat flour, which indicates a substantial continuing deficet in food production. In the developing countries,half the production increase has resulted from increases in yield and the other half has come from the expansion in the area sown to wheat. The increase in production derived from the increase in yield is particularly significant because many of these countries have little additional suitable land that is apt for wheat culture. The high yielding varieties of wheat continue to spread in the developing countries. A survey in 1976 indicated that the improved high yielding varieties are now grown on 25 million hectares in Asia, Africa and Latin America, representing 40 per cent of the wheat production areas in these three continents. The diversity of genetic background of the high yielding varieties now being grown commercially is increasing as more of the national breeding programs in the developing nations release new varieties. CIMMYT continues to distribute both promising advanced lines and unselected F2 materials of widely diverse genetic backgrounds to more than 60 collaborating countries. The aim is twofold, namely, to diversify the genetic resistance to disease and also, hopefully, to identify higher yielding and better adapted varieties. Increasing attention is being given by CIMMYT scientists to identify lines and varieties with a broad resistance range-presumably horizontal in nature. This search is expedited by the large number and wide distribution of testing sites (experimental stations) and scientific colleagues, with whom CIMMYT collaborates around the world. The danger of losses from diseases and insects increases with cropping intensity which produces a more favorable microclimate within the grain field for pests and pathogens. It calls for increased vigilance by Plant breeders and pathologists to offset the increased risks, as far as possible. In a similar way, CIMMYT continues to work on the development of multi-line varieties as another approach to increasing greater genetic variation into commercial varieties in order to reduce the risk from losses from disease. In this approach, extensive research is being done between CIMMYT scientists and the Indian Wheat Research team. The spring (habit) x winter (habit) wheat crossing program which was initiated seven years ago has reached a stage where many of the most promising lines in the preliminary yield nurseries have been derived from this approach. Exciting progress continues to be made in triticale improvement. During the year, 38 advanced lines with excellent grain were found. Unfortunately most of these lines have rather tall weak straw. However, a large number of F2 and F3 plants from several other crosses have been found with equally good grain type combined with good plant type and good fertility. It has become clear during the past several years that triticale will consistently outyield wheat often by 50 to 100 per cent on very acid soils, such as those widely distributed in parts of Brazil, Ethiopia, Kenya and the outer ranges of the Himalayas. |
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