中文摘要：

【目的】研究灌浆期控水和控释肥施用对不同收获期杂交玉米种子产量和质量的影响,明确最适宜的收获时期及有效的水肥管理方式,为中国高质高效玉米制种提供理论和技术支撑。【方法】试验于2014和2015年在甘肃省张掖市甘州区进行,以京科968为试验材料,在田间采用两因素裂区试验设计,主区为水分管理方式,设常规灌溉浇水和授粉后35 d停止浇水2种方式;副区为施肥处理方式,设施用传统复合肥和施用控释肥配比尿素2种处理。从授粉后44 d开始,每隔3 d采集果穗,至授粉后68 d共9个收获期,测定每个时期种子的籽粒水分、百粒重,并计算每公顷的产量和籽粒数（粒数产量）;籽粒自然晾干后用于种子活力分析,包括标准发芽率、人工加速老化发芽率和电导率测定。【结果】施肥和灌水方式均显著影响京科968的制种产量和粒数产量,但对籽粒水分、百粒重和种子活力没有影响。与传统施肥相比,施用控释肥后,制种产量增加3.10%,粒数产量提高2.13%。如果按粒包装销售,施用控释肥可显著提高制种的经济效益,正常灌溉条件下每公顷增收0.44—2.17万元,控水条件下增收0.12—1.35万元。灌浆期控水导致制种产量降低2.01%,粒数产量降低2.48%,经济效益降低0.11—1.78万元。收获期对制种产量、籽粒水分、百粒重和种子活力均有显著影响,但对粒数产量无显著影响。随着收获期推后,籽粒灌浆进程逐渐完成,籽粒水分逐渐降低,而百粒重不断增加。至授粉后68 d,百粒重仍在增加,说明此时京科968种子尚未达到生理成熟。两年的结果表明,授粉后56—65 d,京科968种子的标准发芽率、人工加速老化发芽率均达到最高,而种子浸出液电导率值达到最低,说明此阶段是京科968种子的最佳收获期,既可以保证种子的高活力,又可以有效避免当种子达到生理成熟时收获可能遇到的低温冻害风险。?

英文摘要：

【Objective】The objective of this study was to investigate the effects of water management and controlled-release fertilizer on seed yield and seed quality and to determine the optimal harvest time for maize hybrid JK968. These results will provide theoretical and technical supports for high quality maize seed production in China.【Method】Maize hybrid Jingke968 was grown in Zhangye city, Gansu province, in 2014 and 2015. Field experiments were designed under split-plot. The main plot treatment was two distinct water managements of normal water irrigation and controlled water irrigation（no water irrigation after grain filling stage that is about 35 days after pollination, DAP）. The subplot treatments was two distinct fertilizer treatments of traditional fertilizer（urea and diammonium phosphate） and controlled-release fertilizer（N ： P ： K ration of 24 ： 12 ： 10）. Seed samples were harvested from 44 to 68 DAP with an interval of 3 for investigating seed yield traits（seed yield, seed number per hectare and 100-seed weight） and seed quality traits（seed moisture, standard germination and accelerated aging germination, and electric conductivity.【Result】Fertilization treatment and irrigation management significantly affected seed yield and seed number per hectare, but none of any effects on seed moisture content, 100-seed weight and seed vigor. Compared to traditional fertilizer, control-released fertilizers increased seed yield by 3.10% and seed number per hectare by 2.13%. Economic benefit by control-released fertilizers also increased by RMB 4 400- 21 700 Yuan and 1 200-13 500 Yuan per hectare under normal water condition and controlled water condition, respectively. Controlled water management decreased seed yield and seed number by 2.00% and 2.49%, respectively, and decreased economic benefit from 1 100 to 17 800 Yuan RMB compared to normal water management. Harvest time significantly affected seed yield, seed moisture, 100-seed weight and seed vigor, but showed no effects on seed