Potential Yield Increase of Hybrid Rice at Five Locations in Southern China

Abstract

BackgroundA number of field studies have demonstrated that the yield potential of hybrid rice cultivars is higher than that of inbred cultivars, although the magnitude of difference between hybrid and inbred cultivars at different yield levels has not been described. The objective of this study is to compare the yield increase potential at different yield levels between hybrid and conventional rice. Ten field experiments were conducted at five locations in southern China in 2012 and 2013. At each location, two hybrid and two inbred cultivars were grown at three N levels: high (225 kg/hm2), moderate (161–191 kg/hm2) and the control, zero N (0 kg/hm2).ResultsHybrid rice yielded approximately 8 % more grain than did inbred cultivars in Huaiji, Binyang and Haikou; approximately 7 % more in Changsha; and approximately 19 % more in Xingyi. The high grain yields observed for hybrid rice cultivars were attributed to high grain weight and biomass accumulation at maturity. On average, rice yields were approximately 6.0–7.5 t ha−1 (medium yield) in Huaiji, Binyang and Haikou; approximately 9.0 t ha−1 in Changsha (high yield); and approximately 12.0 t ha−1 (super high yield) in Xingyi. The yield gaps among Huaiji, Binyang and Haikou and Changsha were attributed to the differences in spikelets m−2 and biomass production, whereas the yield gap between Changsha and Xingyi was caused by the differences in grain-filling percentage, grain weight and harvest index. The differences in biomass production among sites were primarily due to variation in crop growth rate induced by varied temperatures and accumulative solar radiation.ConclusionsThe yield superiority of hybrid rice was relatively small in comparison with that of inbred cultivars at medium and high yield levels, but the difference was large at super high yield levels. Improving rice yields from medium to high should focus on spikelets m−2 and biomass, whereas further improvement to super high level should emphasize on grain-filling percentage, grain weight and harvest index. Favorable environmental conditions are essential for high yields in hybrid rice.

Comparison of Agronomic Performance between Japonica/Indica Hybrid and Japonica Cultivars of Rice Based on Different Nitrogen Rates

“…In this study, we observed significant higher spikelet per panicle in Yongyou 12 and Yongyou 538 as compared with Xiushui 134 and Jia 58 (Table 5), which contributed to the higher grain yields of Yongyou 12 and Yongyou 538, in terms of yield components, as suggested by Meng et al [9]. However, this was contradictory to the previous studies that reported the hybrid rice tended to have higher grain filling percentage and grain weight than the inbred rice [31,32]. The discrepant results of these studies could be due to the different types of rice cultivars.…”

No-tillage effects on grain yield and nitrogen requirements in hybrid rice transplanted with single seedlings: Results of a long-term experiment

“…In this study, a representative hybrid rice cultivar Liangyoupeijiu transplanted as single seedlings produced an average grain yield of 9.42 t ha -1 across tillage methods and years (Table 1). This average yield is very close to those yields (9.57 and 9.51 t ha -1 ) obtained from the same cultivar when transplanted with double seedlings in the same location (Huang et al 2011c;Jiang et al 2016). This change in cultural practice cuts seed costs substantially as having minimum number of seedlings per hill (one) reduces seed rate minimizes seed costs, an important factor in the profitability of hybrid rice production.…”

Diagnosis of Nitrogen Nutrition in Rice Leaves Influenced by Potassium Levels

“…Predicted results showed that 70% more food will be needed by 2050 (Long, 2012). With the increasing population and decreasing arable land, it is of great importance to ensure food safety by improving rice yield per unit area (Jiang et al, 2016). Nitrogen (N) and potassium (K) are two elements that are required in great quantities for rice growth and yield formation (Pettigrew, 2008;Zhu et al, 2008;Oosterhuis et al, 2014).…”