Yield of wheat in the United Kingdom: Recent advances and prospects

From 1948 to the present, wheat (Triticum aestivum L,),yields in the UK hav e increased by an average of 110 kg ha-L each year. This rate of increase h as been at least maintained in recent years. The greater yields have been a ssociated with the adoption of cultivars of shorter stature,,which are resi stant to lodging and reach anthesis approximate to 1 wk earlier than old cu ltivars. In the last two decades, most of these cultivars have carried the rht Dib dwarfing gene. The full yield benefits from modern cultivars have d epended on high rates of N fertilization and the use of herbicides and effe ctive fungicides, Data from recent trials with candidate cultivars and F-1 hybrids suggest that further genetic gain in yield will he achieved during the next decade. Improved crop protection through chemicals may also enable farmers to obtain greater yields, In the longer term, substantial genetic gain in yield may be achieved if breeders are able to produce cultivars wit h faster growth rates and greater biomass at maturity. One way to achieve t his would be to modify the photosynthetic enzyme rubisco so that its oxygen ase activity is reduced. However, cultivars with potentially faster growth rates would require even more N fertilizer if their greater yield potential is to be realized.