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Effects of different water regimes and nitrogen application strategies on grain filling characteristics and grain yield in hybrid rice

Sun, Yongjian, Yan, Fengjun, Sun, Yuanyuan, Xu, Hui, Guo, Xiang, Yang, Zhiyuan, Yin, Yaozhu, Guo, Changchun, Ma, Jun
Archiv für Acker- und Pflanzenbau und Bodenkunde 2018 v.64 no.8 pp. 1152-1171
correlation, fertilizer application, filling period, grain yield, hybrids, irrigation management, leaves, nitrogen, nitrogen fertilizers, panicles, rice, seeds, spikelets, tillering
In order to optimize N application and understand how the different combinations of water and N management affect grain filling characteristics and yield, we designed three irrigation regimes (W₁ submerged irrigation, W₂ alternate irrigation, W₃ dry cultivation), and different N application strategies at 180 kg ha⁻¹ in 2010 and 2011. The relationship between grain filling characteristics and grain yield formation were respectively investigated. The results revealed that there were obvious interacting effects of irrigation regime and N application strategies on grain yield and grain-filling characteristics as well. Compared with W₁ and W₃ treatments, under W₂, the N-fertilizer should account for 30% base, 30% tillering, and 40% panicle fertilizer with the last being applied equally at 4th and 2nd leaves emerged from the top. Correlation analysis revealed that grain filling rate during middle grain-filling stage was the largest and contribute more than 50% to grain-filling. Grain yield was significantly related to grain filling rate (Gₘₐₓ or Gₘₑₐₙ), final weight of a kernel (A), and mean grain filling rate (MGR) of the early, mid and late stages during grain filling in inferior spikelets, which is the important reason for water and N coupling effect further to increase yield and fertilizer use efficiency.