Businesses, consultants and scientists sometimes ask themselves whether plant breeders are still able to raise the yield of crops such as winter wheat and potatoes today. More and more articles published in international reviews imply that production is barely increasing in countries where it is already high. The idea prevails that as trees cannot continue to grow until they reach the sky, there must obviously be a yield ceiling. Scientists at Wageningen University decided to study this deeper.
Yield increases by around one per cent per year.
The yield of a crop depends on the genetic characteristics of the variety, soil, climate, and crop management. The scientists analysed official tests on varieties that were carried out between 1980 and 2010. A statistical technique allowed them to separate the influence of weather, CO2 levels and crop management from the effect of the introduction of new varieties. This showed that new varieties introduced between 1980 and 2010 on average all had a higher yield than previous breeds. This applied to winter wheat, spring barley, potatoes grown for starch, and sugar beets, as well as, to a lesser extent, to ware potatoes. Over the period under review, the yield of the breeds of winter wheat and spring barley appearing in the market for the first time increased by around one per cent per year.
The most striking finding was that the yield increase by breeding has not yet levelled off,” Bert Rijk, researcher at the chair group “Plant Production Systems” at Wageningen University, states. “New varieties are better than their predecessors to the same extent today as they were in the early Eighties."