关键词：
Hill dry weight;hybrid rice;panicle number;stem dry weight;tillering duration;tillering rate
摘要：
To compare the tillering pattern of hybrid rice, multiple field experiments were conducted involving three hybrid rice cultivars (HS 995, HS 48 and LYPJ) with three nitrogen fertilizer levels during 2009 to 2011. The experimental sites were selected in the sub-tropical environments of Changsha, Hunan Province in China, and in tropical climate zones of Habiganj and Gazipur in Bangladesh. All parameters of this study were significantly influenced by the locations and mostly the cultivars as well as the N levels. Tests confirmed that (i) panicle number was highest in Hunan and LYPJ showed the superiority even under cross ecosystem. The higher panicle number was the consequential of higher tiller number in both the environments; (ii) tillering rate (TR) responded to higher tillering capability; (iii) lower tiller emergence resulted in low panicle number but showed the higher panicle production efficiency in HS 48 and vice versa in LYPJ; (iv) early tiller emergence at Hunan showed the advantage to higher panicle number; (v) dry weight of stem and hill was more than 60% higher in Hunan and 23% higher in Habiganj over Gazipur site and (vi) higher N dose generated significant increases in hill dry matter, higher tiller number as well as increased the panicle number. Our study suggested that selection should be emphasized on cultivars those boast of more potential to high TR and to produce more dry matter especially at early growth period even under low temperatures in a wider area basis adaptation.
关键词：
crop growth rate;biomass production;hybrid rice;leaf area duration;leaf area index;real-time nitrogen management
摘要：
To compare the grain yield and growth behaviors of hybrid rice, field experiments were conducted in a subtropical environment in Changsha, Hunan Province, China, and in two tropical environments in Gazipur and Habiganj in Bangladesh during 2009 to 2011. Three hybrid rice cultivars were grown under three nitrogen (N) management treatments in each experiment. The results showed that grain yield was significantly affected by locations, N treatments and their interaction but not by cultivars. Changsha produced 8-58% higher grain yields than Bangladesh locations. Sink size (spikelet number per unit land area) was responsible for these yield differences. Larger panicle size (spikelet number per panicle) contributed to greater sink size in Changsha. Aboveground total biomass was greater in Changsha than in Bangladesh locations, whereas harvest index was higher in Bangladesh locations than in Changsha. Crop growth rate (CGR) was greater at Changsha than Bangladesh locations during vegetative phase, while the difference was relatively small and not consistent during the later growth phases. Higher leaf area index and leaf area duration were partly responsible for the greater CGR in Changsha. Real-time N management (RTNM) produced lower grain yields than fixed-time N management in more than half of the experiments. Our study suggested that further improvement in rice yield in the tropical environments similar to those of Bangladesh will depend mainly on the ability to increase panicle size as well as CGR during vegetative phase, and the chlorophyll meter threshold value used in RTNM needs to be modified according to environmental conditions and cultivar characteristics to achieve a desirable grain yield.
作者：
Li Di-qin;Tang Qi-yuan*;Zhang Yun-bo;Qin Jian-quan;Li Hu;...
期刊：
农业科学学报(英文),2012年11(1):134-143 ISSN：2095-3119
通讯作者：
Tang Qi-yuan
作者机构：
[Yang Sheng-hai; Qin Jian-quan; Chen Li-jun; Tang Qi-yuan; Zhang Yun-bo; Li Di-qin; Zou Ying-bin; Li Hu] Hunan Agr Univ, State Key Lab Hybrid Rice, Changsha 410128, Hunan, Peoples R China.;[Peng Shao-bing] Huazhong Agr Univ, CPPC, Wuhan 430070, Peoples R China.
通讯机构：
[Tang Qi-yuan] H;Hunan Agr Univ, State Key Lab Hybrid Rice, Changsha 410128, Hunan, Peoples R China.
会议名称：
全国第十四届水稻优质高产理论与技术研讨会
会议时间：
2011-08-01
会议地点：
长沙
会议论文集名称：
全国第十四届水稻优质高产理论与技术研讨会论文集
关键词：
super hybrid rice;real-time N management;fixed-time adjustable-does N management;grain yield;sheath blight;radiation use efficiency;agronomic-nitrogen use efficiency
摘要：
Poor nitrogen use efficiency in rice production is a critical issue in China. Site-specific N managements (SSNM) such as real-time N management (RTNM) and fixed-time adjustable-dose N management (FTNM) improve fertilizer-N use efficiency of irrigated rice. This study was aimed to compare the different nitrogen (N) rates and application methods (FFP, SSNM, and RTNM methods) under with- and without-fungicide application conditions on grain yield, yield components, solar radiation use efficiency (RUE), agronomic-nitrogen use efficiency (AEN), and sheath blight disease intensity. Field experiments were carried out at Liuyang County, Hunan Province, China, during 2006 and 2007. A super hybrid rice Liangyou 293 (LY293) was used as experimental material. The results showed that RTNM and SSNM have great potential for improving agronomic-nitrogen use efficiency without sacrificing the grain yield. There were significant differences in light interception rate, sheath blight disease incidence (DI) and the disease index (ShBI), and total dry matter among the different nitrogen management methods. The radiation use efficiency was increased in a certain level of applied N. But, the harvest index (HI) decreased with the increase in applied N. There is a quadratic curve relationship between grain yield and applied N rates. With the same N fertilizer rate, different fertilizer-N application methods affected the RUE and grain yield. The fungicide application not only improved the canopy light interception rate, RUE, grain filling, and harvest index, but also reduced the degree of sheath blight disease. The treatment of RTNM under the SPAD threshold value 40 obtained the highest yield. While the treatment of SSNM led to the highest nitrogen agronomic efficiency and higher rice yield, and decreased the infestation of sheath blight disease dramatically as well. Nitrogen application regimes and diseases control in rice caused obvious effects on light interception rate, RUE, and HI. Optimal N rate is helpful to get higher light interception rate, RUE, and HI. Disease control with fungicide application decreased and delayed the negative effects of the high N on rice yield formation. SSNM and RTNM under the proper SPAD threshold value obtained high-yield with high efficiency and could alleviate environmental pollution in rice production.
