Yield comparison between dry seeded and transplanted rice in southern China

Field experiments were conducted at the Experimental Farm of Guangxi University, Guangxi province, southern China in early and late rice-growing seasons in 2012 to compare grain yield and yield attributes between dry seeded and transplanted rice. A hybrid rice cultivar Guiliangyou 2 was grown under dry seeding (DS) and dry transplanting (DT) in each season. Grain yield, yield components, tillering process, biomass production, growth duration, crop growth rate (CGR), leaf area index (LAI), leaf area duration (LAD) and net assimilation rate (NAR) were determined for each establishment method. DS produced higher and equal grain yield than DT in early and late seasons, respectively. The higher grain yield under DS in early season was attributed to improvement in both sink and source. For source, DS had significantly higher panicles/m² than DT, which resulted in larger sink size (spikelets/m²). High tillering capacity was responsible for high panicles/m² under DS. For the source, DS produced significantly higher biomass than DT during reproductive and grain-filling phases. High CGR was responsible for high biomass production under DS. High CGR under DS was attributed to high LAI, LAD and NAR during reproductive phase and to high LAI and LAD during grain-filling stage. No yield superiority observed under DS in late season might be associated with temperature. Mean temperature was lower in late season than in early season by 5.8°C during grain-filling phase. Our results suggest that multi-year and multi-location field experiments should be conducted in future to determine the yield stability of dry seeded rice.