Grain Quality and Yield of Rice in the Main and Ratoon Harvests in the Southern U.S

The ratoon rice system is an energy-saving, high-efficiency cultivation method. Harvests from a two-year field trial with a main crop (MC) and a ratoon crop (RC) were used to evaluate milled grain quality traits and yield performance. The results indicated that chalkiness was significantly lower in the RC than in the MC. Chalkiness ranged from 1.90 to 15.01%, with an average of 6.46%, in the MC and from 0.66 to 3.28%, with an average of 1.50%, in the RC across two years. In addition, nearly all of the RC of the test entries had lower white vitreous (higher translucency) than the MC of the same entry. In 6 of the 20 entries, the MC had longer or wider milled grain than the RC in 2017. The milled rice recovery for the MC was higher in both years, but there was no difference in head rice recovery within the same year. The average total yield (MC+RC) in the two years was 12.6 and 13.0 t/ha, and the two-year average RC yields were 47.5 and 37.3% those of the MC. Our results revealed that the RC milled grains showed better appearance quality than the MC grains, and several genotypes had comparable or even better milled grain quality and yield compared with the check entries that were suitable for the ratoon rice system.