Delayed transplanting reduced grain yield due to low temperature stress at anthesis in machine-transplanted late-season rice

Abstract

AbstractThe development of mechanised large-scale farming has led to changes in rice production systems. Increases in time of farming operations often occur under large-scale farming conditions, which can lead to delayed transplanting (DTP). In this study, field experiments were conducted in the late rice-growing season in 2016 and 2017 to compare the growth stages, growing-season temperature and yield attributes between normal transplanting with 15- to 20-day-old seedlings and DTP with 30-day-old seedlings of two rice cultivars. DTP resulted in 6- and 12-day delays in heading stage for both cultivars in 2016 and 2017, respectively. As a consequence, low temperature stress occurred at anthesis under DTP in both years, which led to significantly reduced spikelet filling and grain yield under DTP for both cultivars. These results confirm that DTP can reduce spikelet filling and grain yield due to low temperature stress at anthesis in machine-transplanted late-season rice. This finding highlights that greater efforts should be made to develop high-yielding short-duration rice cultivars to meet the development of mechanised large-scale rice farming.