摘要
【目的】选用氟节胺复配型、缩节胺复配型2种化学打顶剂,研究田间喷施化学打顶剂对棉花株型特征、冠层结构、群体光合生产及产量的影响,分析冠层结构变化对群体光合生产和产量的影响,为棉花化学打顶技术的应用提供理论依据。【方法】选用北疆棉区主栽品种(新陆早45号)和主推品种(系)(中棉所50、45-21)为试验材料,在田间自然条件下,以常规人工打顶的棉花为对照,分别测定不同棉花品种(系)株高、株宽、叶面积指数、叶片叶绿素含量、冠层不同部位透光率、群体光合速率及产量构成等指标。研究化学打顶技术对棉花叶面积指数、冠层透光率、群体光合速率及产量的影响。【结果】与人工打顶的棉花相比,化学打顶的棉花株高显著高于人工打顶处理,且喷药后生长量较大;株宽显著小于人工打顶处理,喷药后横向生长被明显抑制。化学打顶的棉花叶面积指数和叶片叶绿素含量较高,且高值持续期长,至初絮期(出苗后115 d)仍维持较高的值,与人工打顶的棉花相比差异均达到极显著水平;冠层上、中部透光率较高,生育后期冠层下部漏光损失较小。化学打顶的棉花群体光合速率显著高于人工打顶,且高值持续期长,至初絮期仍维持在16.04μmol·m^(-2)·s^(-1)以上,较人工打顶的棉花高出14.35%—36.35%,差异均达到显著水平;群体呼吸速率在达到峰值前显著高于人工打顶的棉花,峰值后与人工打顶的棉花无显著差异;群体呼吸速率占群体总光合速率的比率高于人工打顶的棉花。化学打顶的棉花单株结铃多,其中氟节胺处理棉花产量高于人工打顶。【结论】棉花化学打顶技术具有塑造株型、调节棉花冠层结构形成的重要作用;同时棉花冠层上、中部透光率大,改善了冠层中下部光环境,保证了冠层各部位均匀的光分布。化学打顶的棉花叶面积指数高且高值持续期长,增�
【Objective】 The objectives of this two-year field experiment were to study the effects of two chemical topping agents, Flumetralin and Mepiquat chloride, on the characteristics of plant type, canopy structure, canopy photosynthetic production and yield of cotton and to determine how the changes of canopy structure affect canopy photosynthetic production and yield. The results of this study will provide a theoretical basis for more effective use of chemical topping agents.【Method】The study included two cotton cultivars Xinluzao 45 and Zhangmiansuo 50 and one cotton strain 45-21. Conventional manual topping was used as the control treatment. Plant height, plant width, leaf area index（LAI）, leaf chlorophyll contents, canopy light transmittance, canopy apparent photosynthetic rate, and yield components were among the variables that were measured. The effects of chemical topping technology on LAI, canopy light transmittance, canopy apparent photosynthetic rate and yield were studied. 【Result】 Plant height was significantly higher in the chemically-topped treatments than in the manually-topped treatment, plant width was significantly lesser in the chemically-topped treatments than in the manually-topped treatment, and lateral growth was significantly inhibited after spraying. The LAI and leaf chlorophyll contents were greater in the chemically-topped treatments than in the manually-topped treatment, the difference in LAI and leaf chlorophyll contents were extremely significant at the early boll opening stage. Light transmittance in the upper and middle canopy layers was greater in the chemically-topped treatments than in the manually-topped treatment. However, late in the growing season, light transmittance in the lower canopy layers was lesser than in the manually-topped treatment. Leaf chlorophyll contents increased to a maximum and then decreased at the end of the growing season. Chemical topping increased leaf chlorophyll content. Canopy apparent photosynthetic rates were significantly greater in th
出处
《中国农业科学》
CAS
CSCD
北大核心
2016年第9期1672-1684,共13页
Scientia Agricultura Sinica
基金
国家"十二五"科技支撑计划(2014BAD09B03)
关键词
棉花
化学打顶
冠层结构
群体光合生产
产量
cotton
chemical topping
canopy structure
canopy photosynthetic production
yield
