Agronomic performance of late-season rice in South China

Abstract

a Southern regional collaborative innovation center for Grain and oil crops (cicGo), Hunan agricultural university, changsha, P.r. china; b Key laboratory of crop cultivation and Farming System, Guangxi university, nanning, P.r. china ABSTRACT Improving rice yields is critical for global food security. China is a major rice-producing country having two rice cropping systems, i.e. single-season rice cropping system and a double-season system with both early-and late-season rice. There have been reports on the sink-source traits contributing to high grain yield for single-and early-season rice, but such information is limited for late-season rice. In this study, field experiments were conducted at the research farm of Guangxi University, Nanning, Guangxi Province, China in the late rice-growing season. Grain yield and sink-source traits were compared among five cultivars (Guiliangyou 2, Teyou 838, Y-liangyou 087, Teyou 582, and Yuxiangyouzhan) in 2012 and then three cultivars (Guiliangyou 2, Teyou 838, and Y-liangyou 087) in 2013. Y-liangyou 087 produced 6-26% higher grain yield than did the other cultivars. This higher grain yield was driven by improvements in sink-source capacity. Sink capacity was 8-31% higher in Y-liangyou 087 than in the other cultivars. Well-balanced relations between spikelets m −2 and grain weight was responsible for the higher sink capacity in Y-liangyou 087. The result was that Y-liangyou 087 produced 11-17% greater biomass (source capacity) than did the other cultivars. The greater source capacity in Y-liangyou 087 was mainly attributed to higher radiation use efficiency (RUE). Our study suggests that enhancing sink capacity through balanced relations between number of spikelets per unit land area and grain size, while improving source capacity through increasing RUE is a feasible way to achieve higher grain yield of late-season rice in South China.

Seasonal changes in crop growth and grain yield of different japonica rice cultivars in southeast China

“…() evaluated a series of inbred japonica varieties and determined that the grain yield of inbred japonica varieties was 10.00 ± 0.21 t ha −1 , which did not differ significantly from the indica varieties (9.40 ± 0.96 t ha −1 ). Furthermore, in the current study, the Nanjing46 variety had a grain yield of 7.3 t ha −1 during the 2016 late season, which was comparable to the grain yield of the elite indica rice in the late season (Huang et al., ). These results indicated a remarkable variability in grain yield in the inbred japonica varieties, and there are great potential to breed out the high yield inbred japonica for the late season.…”

“…However, there were large yield differences in late‐season rice within rice types. Previous research has indicated that grain yields is ranked in the order of indica‐japonica hybrid variety > elite indica variety > inbred japonica variety (Cheng et al., ; Huang et al., ). The superiority of the indica‐japonica hybrid variety over the inbred japonica variety was confirmed in the current research.…”

“…Higher LAI at the panicle initiation and heading stages enhanced biomass accumulation by increasing in canopy intercepted solar radiation in the indica‐japonica hybrid rice cultivars Yongyou538 and Yongyou1538, compared to the inbred japonica cultivars Nanjing46 and Jia58 (Figure ). In contrast, a higher radiation use efficiency is generally correlated with the improved leaf photosynthetic traits during the reproductive and/or grain filling stages (Campbell et al., ; Huang et al., ). However, our study did not detect a significant difference in the photosynthetic rate of flag leaves between the hybrid and inbred japonica cultivars during the late season (Figure ), which indicated that greater biomass accumulation in the indica‐japonica hybrid cultivars might attribute to the larger LAI rather than improved photosynthetic rate in flag leaf, compared to the inbred japonica cultivars.…”

“…Consequently, further research on the suitable varietal characteristic traits of japonica rice growing under the late season is lacking. Literature on indica rice during the late season suggests that late season high grain yield might be achieved by enhancing sink capacity, while improving source capacity (Huang et al., ). The high sink capacity mainly comes from improved spikelets per panicle and panicles per unit area (Liu et al., ; Yang et al., ).…”

Reduction in Fertilizer Input´s Has No Significant Affect on Yield or Performance of Early- and Late-season Indica Hybrid Rice

“…The GNP and EPN had super-parental advantages (Li et al, 2016). The highest yield of lateseason hybrid rice was 9.64 t ha -1 , whibch produced a 6-26% higher grain yield than that of the other cultivars because the higher grain yield was driven by improvements in sink-source capacity (biomass production, panicles and spikelets per m −2 , and grain weight) (Huang et al, 2017b); In this study, it was shown that the average yield of late-season rice was 8.44 t ha -1 and 8.75 t ha -1 in 2017 and 2018, respectively (Table S3). Compared with the inbred lines, the average yield of late-season hybrid rice increased by 4.65% and 12.35% in 2017 and 2018, respectively (Table S4).…”