Two genes, two harvests: Adapting barley for double cropping

Growing two crops in succession on the same land requires a tight schedule. In parts of central and eastern China, farmers sow barley in autumn and harvest it in late spring. It is then followed by a summer crop, such as rice. For this cropping sequence to succeed, the barley must mature in time. An early harvest also helps the crop avoid heat and rain toward the end of the growing season.