Maintenance of Crop Growth through 30 Days after Silking Contributes to Achieving Super-High Yield of Spring Maize

摘要

Jilin Province is a major spring maize area of China with the highest regional yield. Nevertheless, a large yield gap existed between actual and potential yield. A super-high yield (> 15 t ha–1) is needed to fulfil the increasing demand. However, yield has been limited due to the lack of knowledge on crop performance in relation to super-high yielding managements. Ten field experiments in Jilin Province from 2008 to 2011 were summarized to understand the growing process of high-yielding spring maize. Plants were categorized into high yield (HY) plants which had a yield > 12 t ha–1, medium yield (MY) plants which had a yield of 9 – 12 t ha–1, and low yield (LY) plants which had a yield < 9 t ha–1. Crop growth during vegetative stages showed no significant differences among yield categories. HY plants grew faster than LY and MY plants after the twelve-collar stage, and the difference became more and more pronounced during silking to 30 days after silking, and even afterwards. Moreover, HY plants had a shorter vegetative period than either LY or MY plants without impacts in vegetative growth, and longer reproductive period, which contributed to better kernel formation and filling. HY plants also had the capacity to maintain a high leaf area index (LAI) at 30 days after silking, which provided for a continuous dry matter accumulation during and after this period and thus resulted in a super-high yield. Hence, special attention should be paid during the 30 days after silking in order to maintain a high photosynthetic capacity and achieve a super-high yield.