Yield of Wheat in the United Kingdom: Recent Advances and Prospects

From 1948 to the present, wheat (Triticum aestivum L.) yields in the UK have increased by an average of 110 kg ha⁻¹ each year. This rate of increase has been at least maintained in recent years. The greater yields have been associated with the adoption of cultivars of shorter stature, which are resistant to lodging and reach anthesis ≈1 wk earlier than old cultivars. In the last two decades, most of these cultivars have carried the rht D1b dwarfing gene. The full yield benefits from modern cultivars have depended on high rates of N fertilization and the use of herbicides and effective fungicides. Data from recent trials with candidate cultivars and F₁ hybrids suggest that further genetic gain in yield will be 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 with faster growth rates and greater biomass at maturity. One way to achieve this would be to modify the photosynthetic enzyme rubisco so that its oxygenase 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.