To compare the effects of slow-release nitrogen fertilizer at six different levels on the flag leaf chlorophyll fluorescence characteristics of super hybrid rice, a field fertilization experiment was conducted with su...To compare the effects of slow-release nitrogen fertilizer at six different levels on the flag leaf chlorophyll fluorescence characteristics of super hybrid rice, a field fertilization experiment was conducted with super hybrid rice Y Liangyou 1 as a test material. The photosynthetic electron transport rate （ETR）, effective quantum yield （EQY）, photochemical quenching coefficient （qp）, and non-photochemical quenching coefficient （NPQ） of flag leaves were measured at the initial heading, full heading, 10 d after full heading and 20 d after full heading stages. Results showed that the values of ETR, EQY and qp increased with rice development from initial heading to 20 d after full heading, whereas the NPQ decreased. During the measured stages, ETR, EQY and qp increased initially and then decreased as nitrogen application amount increased, but they peaked at different nitrogen fertilizer levels. The maximum ETR and EQY values appeared at the treatment of 135 kg/hm2 N. In conclusion, the optimum nitrogen amount for chlorophyll fluorescence characteristics of super hybrid rice was 135-180 kg/hm2.展开更多
The responses of five inter-specific lowland rice cultivars （NERICA-L-19, NERICA-L-20, NERICA-L-41, NERICA-L-42, and NERICA-L-60） and four improved Oryza sativa cultivars （FKR 19, BW 348-1, WITA 4, and SIPI 6923033...The responses of five inter-specific lowland rice cultivars （NERICA-L-19, NERICA-L-20, NERICA-L-41, NERICA-L-42, and NERICA-L-60） and four improved Oryza sativa cultivars （FKR 19, BW 348-1, WITA 4, and SIPI 6923033） to levels of phosphorus and nitrogen fertilization were compared on a Typic Natrustalfat Kadawa in the Nigerian Sudan Savanna in 2006 and 2007 The responses of the NERICA-L eultivars to N and P fertilization were similar to the O. sativa cultivars. In a dry year （2007）, the NERICA-L cultivars gave higher yields than O. sativa cultivars. Phosphorus level did not significantly affect crop physiology, yield, and yield components of all the cultivars. Pooled across cultivars, N and P levels, days to panicle initiation, mid-flowering and maturity were, respectively delayed by 17.0, 15.6 and 6.4 days in 2007 compared to 2006. NERICA-L-42 and NERICA-L-41 were the most stable, exhibiting the least difference in duration to maturity between the two years （3.5 and 4.4 days, respectively）, and could therefore be more adapted to rain-fed environments prone to frequent droughts. Increasing N levels from 0 to 120 kg hal produced yield increments of 62.9 and 37.2% in 2006 and 2007, respectively. Cultivars FKR 19 and WITA 4 gave higher yields in 2006 （3940 and 3542 kg ha^-1, respectively）, while in 2007, NERICA-L-42, NERICA-L^-19 and NERICA-L-20 ranked among the highest in grain yield （3935, 3807 and 3726 kg hal, respectively） and could be recommended to resource-poor farmers. a展开更多
基金financially supported by the National Key Technology Support Program(Grant No.2006BAD02A13)the Dedicated Fund 511th for Agricultural Development of Hunan,China(Grant No.2006NK1001)
文摘To compare the effects of slow-release nitrogen fertilizer at six different levels on the flag leaf chlorophyll fluorescence characteristics of super hybrid rice, a field fertilization experiment was conducted with super hybrid rice Y Liangyou 1 as a test material. The photosynthetic electron transport rate （ETR）, effective quantum yield （EQY）, photochemical quenching coefficient （qp）, and non-photochemical quenching coefficient （NPQ） of flag leaves were measured at the initial heading, full heading, 10 d after full heading and 20 d after full heading stages. Results showed that the values of ETR, EQY and qp increased with rice development from initial heading to 20 d after full heading, whereas the NPQ decreased. During the measured stages, ETR, EQY and qp increased initially and then decreased as nitrogen application amount increased, but they peaked at different nitrogen fertilizer levels. The maximum ETR and EQY values appeared at the treatment of 135 kg/hm2 N. In conclusion, the optimum nitrogen amount for chlorophyll fluorescence characteristics of super hybrid rice was 135-180 kg/hm2.
文摘The responses of five inter-specific lowland rice cultivars （NERICA-L-19, NERICA-L-20, NERICA-L-41, NERICA-L-42, and NERICA-L-60） and four improved Oryza sativa cultivars （FKR 19, BW 348-1, WITA 4, and SIPI 6923033） to levels of phosphorus and nitrogen fertilization were compared on a Typic Natrustalfat Kadawa in the Nigerian Sudan Savanna in 2006 and 2007 The responses of the NERICA-L eultivars to N and P fertilization were similar to the O. sativa cultivars. In a dry year （2007）, the NERICA-L cultivars gave higher yields than O. sativa cultivars. Phosphorus level did not significantly affect crop physiology, yield, and yield components of all the cultivars. Pooled across cultivars, N and P levels, days to panicle initiation, mid-flowering and maturity were, respectively delayed by 17.0, 15.6 and 6.4 days in 2007 compared to 2006. NERICA-L-42 and NERICA-L-41 were the most stable, exhibiting the least difference in duration to maturity between the two years （3.5 and 4.4 days, respectively）, and could therefore be more adapted to rain-fed environments prone to frequent droughts. Increasing N levels from 0 to 120 kg hal produced yield increments of 62.9 and 37.2% in 2006 and 2007, respectively. Cultivars FKR 19 and WITA 4 gave higher yields in 2006 （3940 and 3542 kg ha^-1, respectively）, while in 2007, NERICA-L-42, NERICA-L^-19 and NERICA-L-20 ranked among the highest in grain yield （3935, 3807 and 3726 kg hal, respectively） and could be recommended to resource-poor farmers. a
