苗期不同浓度多效唑处理对豫南粳稻秧苗素质及产量构建的影响

Different Concentrations of Paclobutrazol on Seedling Quality and Yield Composition of Japonica Rice in Southern Henan

为探明苗期喷施多效唑对豫南粳稻调控的影响,本试验利用‘信粳1787’和‘南粳5718’2个品种粳稻,通过一叶一心喷施不同浓度的多效唑,其中浓度(以有效成分计)分别设M0(0 mg/L)、M1(40 mg/L)、M2(80 mg/L)、M3(120 mg/L)、M4(160 mg/L)和M5(200 mg/L)共6种施用水平。2020—2021年评估了不同浓度多效唑对其秧苗素质、干物质量、SPAD值及产量构成的影响。结果表明:随着浓度的增加,2 a 2个品种苗高都降低,根系增长,有利于分蘖的发生,拔节期、齐穗期和成熟期干物质积累量随着浓度的增加出现先增加后降低的趋势,SPAD值都有所增加;产量构成上,随着浓度的增加除穗粒数减少外,其他指标较对照都有所增加,其中‘信粳1787’各指标在M4时最佳,‘南粳5718’在M3表现较好。综上,喷施适宜浓度多效唑可提高水稻秧苗素质、干物质的量、SPAD值及产量。

To explore the regulation effect of spraying paclobutrazol at seedling stage on japonica rice in southern Henan Province,in this study,two japonica rice varieties,‘Xinjing 1787’and‘Nanjing 5718’,were used as materials,and different concentrations of paclobutrazol were sprayed through one-leaf and one-heart.Six concentrations(based on active components)were set as M0(0 mg/L),M1(40 mg/L),M2(80 mg/L),M3(120 mg/),M4(160 mg/L)and M5(200 mg/L).The effects of different concentrations of paclobutrazol on seedling quality,dry matter weight,SPAD value and yield composition were evaluated from 2020 to 2021.The results showed that with the increase of paclobutrazol concentration,the seedling height of the two varieties decreased in the two years,the root growth was conducive to tillering,the dry matter accumulation at jointing stage,full heading stage and maturity stage increased first and then decreased,and the SPAD value increased.In terms of yield composition,with the increase of paclobutrazol concentration,except that the number of grains per spike decreased,other indexes increased compared with the control.All indexes of‘Xinjing 1787’were the best at M4,and‘Nanjing 5718’had a better performance at M3.In conclusion,spraying paclobutrazol at appropriate concentrations could improve seedling quality,dry matter weight,SPAD value and yield of japonica rice in southern Henan.