Background: Improvement of crops’ varietal traits not only involve the selection of superior varieties by research institutes or firms, but also depends on the adoption by farmers. In order to promote research institutes or seed firms developing superior new varieties, the Chinese government has established crop varietal approval system policies since early 1980s. Subsidies for growing superior crop seed varieties have been introduced since 2000s to stimulate farmers to employ superior seeds with improved traits in the production.
Results: Using data on nationally approved rice varieties and farmers’ adopted varieties, this study examines rice varietal trait changes in China over the past four decades and explores the impact of national crop varietal approval policies on approved rice traits as well as the effect of seed subsidies on adopted rice trait changes. The results show that the yield of approved varieties and adopted varieties showed an upward trend over the past decades, but the volatility of approved varieties was significantly stronger than that of adopted varieties, and the yield of approved varieties was slightly higher than that of adopted varieties in most years. The rice quality of approved rice varieties showed a trend of continuous improvement, but the adopted varieties showed a downward trend. The disease resistance of the approved varieties failed to show an increasing trend overall, while the adopted varieties remained unchanged. National crop variety approval policies exert a significant positive impact on approved rice yield traits but exert a negative influence on disease resistance. Subsidies for superior seed varieties significantly increase adopted rice quality but decrease yield.
Conclusions: The results suggest that national crop variety approval policies are the gatekeeper of improved rice, so the government could improve the policies to more meet farmers’ and finally consumers’ needs. However, if the government were targeted at increasing rice yield through subsidies for superior seed varieties, it might not be helpful.