Can optimizing seeding rate and planting density alleviate the yield loss of double‐season rice caused by prolonged seedling age?

Abstract Prolonged seedling age (PS) caused by delayed transplanting frequently occurs in double‐season rice (Oryza sativa L.), leading to a significant grain yield loss. However, it is not clear whether optimizing the seeding rate in the nursery and planting density in the field could compensate for this yield loss. Field experiments with two seedling age, two planting density, and two seeding rate treatments were conducted in the early and late growing seasons of 2013 and 2014 in Wuxue County, Hubei Province, China. Increasing the planting density significantly increased grain yield but couldn't completely alleviate the negative effect of PS on grain yield in both early and late growing seasons. Reducing the seeding rate in the nursery significantly increased the grain yield in both seedling age treatments in the late season with an average of 4.4% across treatments and years. There was a significant interaction effect between seedling age and seeding rate on grain yield in the early season, suggesting that yield loss could be significantly mitigated by reducing seeding rate. In conclusion, optimizing seeding rate and planting density could partially compensate for the yield loss caused by PS.