The researchers studied how weedy rice grows in Korean farmer's fields. They found that weedy rice is more common in fields where rice is directly seeded rather than transplanted. In transplanted fields, weedy rice mostly grows within the hills of cultivated rice, while in directly seeded fields, it grows between the hills or rows of rice. Weedy rice is more likely to occur in fields with non-recommended rice varieties. The researchers suggest that weedy rice survives by mixing with cultivated rice seeds in transplanted fields, and by natural means in directly seeded fields.