Ecological Adaptability of Zhengdan 958 Hybrid in Northeast of China

Abstract

Zhengdan 958 has been the leading maize (Zea mays L.) hybrid in resent years. In order to study its ecological adaptability and fully exert its potential productivity, we conducted a group of field experiments at 22 sites with the latitude ranged from N 40°07′ to N 48°08′ and annul ACT from 2 916 to 4 380℃ in Northeast of China where spring maize were largely grown. The result showed that there were significantly negative correlation between ACT, precipitation and latitude in the postsilking stage (P0.01).The hybrid grain yield showed a difference with growth process due to the variable thermal conditions. The grain yield, 1000-kernal weight, entire growth days obeyed a quadratic relationship (P0.05), with the latitude ascending, the days of emergence were increased and the days from silking to physiological maturity or harvest were decreased. In addition, there was no any significant correlation between latitude and kernel number. The highest potential yield of Zhengdan 958 occurred in some areas where ACT was from 3 450–3 700℃. Zhengdan 958 may not be safely physiological matured where ACT was less than 3 200℃ and its kernel weight also decreased fast. The study also showed that meteor-ecological environment has a more significant effect on 1000-kernal weight than on kernel number of Zhengdan 958 under the varied northeastern weather conditions. Therefore, dif-ferent 1000-kernel weight might result in different grain yields in this region. The thermal deficiency in post-silking stage is the leading limit factor in those regions with high latitude and lower temperature where maize yield is lower than that in other areas. A map of the north line for safetly planting the Zhengdan 958 in Northeast was made based on ACT.