玉米冷害的关键期及生育不良型冷害

本文结果是利用黑龙江省东部山区形成的垂直气温条件的差异,采取地理播种法和地理移栽法取得的。低温对玉米生育的影响是一个缓慢积累过程。幼苗期低温处理,对抽穗、成熟和产量的影响甚小,随着处理期后延,减产逐渐加重,以灌浆期低温处理为最重。因此,低温影响作物产量的关键期是抽穗后的灌浆期。玉米早熟种从抽穗到成熟需要积温800℃,还需要≥20℃的高温日数20天以上,才能成熟良好。玉米冷害除了延迟型、障碍型、混合型三种类型外,还有生育不良型冷害。该类型特点是:苗期阶段低温,使作物生长发育不良,造成减产,但不延迟玉米的成熟。

THE CRITICAL STAGE AND POOR-DEVELOPMENT TYPE OF CHILLIN INJURY IN CORN

The effect of chilling on the development of corn was a slow accumulative process. Chilling treatment at seedling stage did not significantly influence tasseling,maturity and yield of corn. When the chilling treatment was delayed, decrease of yield became more and more severe and reached its peak when chilling treatment was conducted in seed filling period. Therefore, the critical stage injury is the filling stage following tasseling. Accumulated temperature from tasseling to maturity for early corn cultivats is 800℃, and more than 20 days of temperature≥20℃ are still needed for better ripening. There are three types of chilling injury in corn namely delaying, sterile and mixed. Besides, there is still a type of poor-development. The characteristic of this type is that chilling at seedling stage will cause poor growth and development of corn leading to yield decrease, but ripening of corn will not be delayed.