Abstract:

【Objective】 The objective of this experiment was to study the yield increasing effects and ecological adaption of the maize of timely late harvest technology on a large regional scale, and to provide a theoretical basis for maize production. 【Method】 41 experiment sites were set up in the main maize producing areas (Northeast China, North China and Huanghuaihai area ) in 2007 and 2008 to study the yield increasing effects of the maize of timely late harvest . This experiment was set up with two treatments of putting off 7 days’ harvest and putting off 14 days’ harvest. 【Result】 Timely late harvest had significant increasing effects on maize yield and 1000-grain-weight. With putting off 7 days’ harvest, the maize yield increased by 4.20% and 4.94% compared to CK in 2007 and 2008. With putting off 14 days’ harvest , the yield increased by 7.79% and 7.92% compared to CK. The yield increasing effects of the maize of timely late harvest increased with latitude decreasing (Northeast China＜North China＜Huanghuaihai area). The yield increasing range of putting off 7 days’ harvest were 0.08%?d-1 and 0.06%?d-1 in 2007 and 2008 with 1 degree decreasing in latitude. The yield increase range of putting off 14 days’ harvest were 0.06%?d-1 and 0.07%?d-1 in 2007 and 2008 with 1 degree decreasing in latitude. Maize timely late harvest improved the utilization efficiency of light and temperature. The ≥10℃ accumulated temperature were increased by 109.5℃ and 194.5℃ compared to CK when put off 7 days and 14 days harvest. At the same time, the sunshine duration were increased by 44.55 h and 83.38 h. 【Conclusion】 Timely late harvest has significant increasing effects on maize yield and the range increases with latitude decreasing. Appropriate late harvest time are related to local ecological conditions.

Key words: maize')">maize, timely late harvest, yield, increasing yield