栽培密度對玉米生育及產量之影響Ⅱ.子粒充實期

The Effects of Planting Density on the Growth and Yield of Corn Ⅱ. Grain-Filling Period

姜義展(Yih-Jan Jiang) ； 魏夢麗(Meng-Li Wei) ； 陳烈夫(Lit-Fu Chan) ； 劉大江(Dah-Jiang Liu)

《中華農業研究》 44卷1期 (1995/03) Pp. 37-48

https://doi.org/10.29951/JARC.199503.0005

摘要

本試驗採用玉米品種臺農一號為材料，以吐絲期具不同營養生長量但吐絲後具有相似生育環境之處理，探討子粒充實期間植株產量生理性狀表現。於1991及1992年秋作進行田間試驗，行距約為75cm，株距分為11與22cm兩種處理，第一年試驗於吐絲期將部份小區株距自11cm間拔為22cm，第二年於雄穗分化始期與吐絲期進行相同處理，又於吐絲期將部份小區株距自22cm間拔至44cm，分析子粒充實期間不同器官之乾物質與氮素累積性狀，解析對產量的影響。密植栽培降低植株在吐絲期之營養生長量；吐絲後如維持相同株距，則吐絲期營養生長量較低之處理，植株在子粒充實前期（吐絲後0~24日）及後期（48~65日）的單株乾物質生產量較高，但分配至子粒之比率則較低。子粒充實前期所生產的光合物質平均分配於子粒及果穗其他部位，器官間可能有競爭現象，以疏植區最為明顯。吐絲期營養生長量較低之植株於充實中期，及吐絲期營養生長量較高之植株於充實後期，其全株光合物質產量不足以供應子粒充實之需。在氮素累積性狀方面，吐絲期氮素累積量較低者，於子粒充實前期與中期（吐絲後24~48日）有較高的氮素同化能力。多數處理於子粒充實全期之全株氮素累積速率低於子粒氮素累積速率，以充實中期的差異最為顯著；但吐絲期營養生長量與氮素累積量最低之處理，可同化較多量氮素，反而表現較佳之供需平衡關係。玉米植株氮素利用效率因密植而升高，主要受氮素吸收效率影響。如吐絲期營養生長與氮素累積量不同，而吐絲後維持相同之行株距，其氮素利用效率與多數組成因子之表現並無顯著差異，顯示臺農一號玉米品種之氮素利用對栽培密度呈現較為穩定的反應。吐絲期乾物質與氮素累積量較低之處理，植株在吐絲後具有較高的光合物質與氮素同化作用能力，對子粒產量具有明顯的補償及緩衝作用。

關鍵字

玉米 ； 栽培密度 ； 子粒充實 ； 乾物質累積 ； 氮素累積 ； 氮素利用

並列摘要

The purpose of this experiment was to investigate the pattern of dry matter and N accumulation by corn hybrid Tainung No. 1 during kernel-filling and its influence on yield performance for plants with differed vegetative growth at silking. Field experiments were conducted in the fall crops of 1991 and 1992 with a row spacing of 75 cm and within-row spacings of 11 and 22 cm. The spacing was altered from 11 to 22 cm in part of the plots by thinning the stand at silking (1991) and at tassel initiation and silking (1992). In 1992, thinning was also performed to enlarge the spacing from 22to 44cm. Dense-planting tended to decrease the vegetative growth at silking. With the same population density, plants with less vegetative growth at silking could produce more dry matter during the early (0~24 days after silking, DAS) and late (24~48 DAS) kernel-filling periods. However, partition of dry matter to the kernel was less significant as compared to other treatments. The amount of dry matter accumulated during 0~24 DAS was evenly distributed to kernel and other parts of the ear, indicating possible competition between organs. The phenomenon was most significant for the low-spacing treatment. The amount of dry matter produced by plants with less and more vegetative growth could not meet the demand by the developing kernels during the middle and late kernel-filling periods, respectively, which suggests a very complex source-sink relationship as a result of plant-spacing treatment. The assimilation rate of N was lower for the whole plant than for the kernels throughout the entire kernel development phase, especially during the period of 24~48 days after silking. However, plants with less vegetative growth and N accumulation at silking exhibited higher N assimilation ability and hence better source-sink relationship in N during this period. The N use efficiency (NUE) increased with increasing population density, due completely to higher uptake efficiency. The NUE and most of its components were similar among treatments in spite of the different amounts of dry matter and N accumulated at silking. This implies a stable response in N utilization to population density for corn hybrid Tainung No. 1. Under the current experimental conditions, kernel yield was not significantly affected by the status of vegetative growth at silking beacause of the buffering ability of the plants in terms of dry matter and N assimilation during kernel-filling.

並列關鍵字

Zea mays ； plant spacing ； kernel-filling ； dry matter accumulation ； N accumulation ； N use efficiency