Yield improvement
Crop yields are dependent on interactions of socio-economical, biological, technological and ecological factors. Considerable controversy exists among scientists regarding the achievements that can be made to further increase wheat yield per unit of area. A large gap exists between yields that have been accomplished in experimental fields versus those attained in farmers’ fields. The absolute yield, based on genetic potential, is projected to be 20 tonnes/ha (Hanson et al., 1982). The highest commercial attainable yield reported is 14 tonnes/ha under a given environment, location and year (Cook and Veseth, 1992). In contrast, the wheat yield average for the world during the period 1993-1995 was 2.5 tonnes/ha. Closing the yield gap must, of necessity, be one of the major goals of organizations involved with world food policy and wheat research for the future.
Current research to improve wheat yields covers a broad front and includes further mixing of germplasm through crossing, interspecific and intergeneric hybridization, biotechnology techniques, hybrid wheat, basic studies on the physiology of the wheat plant and on the host-plant relationships of various pests that attack it and numerous other important research avenues.