苗期不同浓度多效唑对南方晚粳稻秧苗素质、茎蘖动态及产量的影响

Effects of Different Concentrations of Paclobutrazol in Seedling Stage on Seedling Quality, Tillering Dynamics and Grain Yield of japonica Rice During Late Cropping Season in Southern China

【目的】通过喷施多效唑来达到高产所需的足穗,解决南方晚粳稻有效穗数不足的问题。【方法】设计以品种为主区、多效唑浓度为副区的裂区试验。以镇稻11和甬优2640为晚粳稻材料,以晚籼稻H优518为对照;多效唑浓度(以有效成分计)分别设A1(0 mg/L)、A2(84 mg/L)、A3(120 mg/L)、A4(156 mg/L)和A5(192mg/L)共5种施用水平。2014-2015年评估了不同浓度多效唑对南方晚粳稻秧苗素质、茎蘖动态及产量的影响。【结果】随多效唑浓度增加,2年各品种秧苗苗高均逐渐降低;H优518及甬优2640秧苗叶龄及SPAD值逐渐增加,而镇稻11却先增后降;三品种秧苗单株根长、根数、分蘖数以及有效穗数、结实率、籽粒充实度和产量均随苗期喷施多效唑浓度的增加呈现先增后降趋势,其中H优518及甬优2640两品种的上述指标均在A4时最高,镇稻11在A3表现最佳。【结论】喷施适宜浓度多效唑可显著提高水稻秧苗素质、有效穗数及产量。其中,H优518及甬优2640以A4(156 mg/L)时产量表现最好,而镇稻11却在A3(120 mg/L)时产量达到最高。

【Objective】Sufficient panicle number holds the key to higher yield of late japonica rice in southern China.Our goal is to achieve sufficient panicle number by paclobutrazol treatment so as to gain higher yield.【Method】The split plot was designed with variety as main area and paclobutrazol concentrations as sub-area.Zhendao 11 and Yongyou 2640 were used as late japonica rice materials and H you 518 as control.Five concentrations of paclobutrazol(calculated by active component;A1,0 mg/L,A2,84 mg/L,A3,120 mg/L,A4,156 mg/L and A5,192 mg/L)were used in the present field experiment.We investigated the effects of different concentrations of paclobutrazol on seedling quality,tillering dynamics and yield of late japonica rice in southern China between 2014 and 2015.【Result】The seedling height gradually decreased during the two years.The leaf age of seedling and SPAD of H you 518 and Yongyou 2640 gradually increased,while those of Zhendao 11 increased first and then decreased with increasing concentrations of paclobutrazol.The seedling root length,root number,tiller number,productive panicle number,seed setting rate,grain plumpness and yield of the three cultivars increased first and then decreased along with the rising concentrations of paclobutrazol.These indexes of H you 518 and Yongyou 2640 peaked at 156 mg/L of paclobutrazol,and Zhendao 11 at 120 mg/L of paclobutrazol.【Conclusion】Rice seedling quality,panicle number and yield were significantly enhanced by applying suitable concentrations of paclobutrazol.The yield of H you 518 and Yongyou 2640 peaked at 156 mg/L of paclobutrazol,while Zhendao 11 reached the highest yield at 120 mg/L of paclobutrazol.