LAUSR

BACKGROUND Global warming has led to unreasonable trans-regional planting of late-maturing maize varieties in northeast China, which has hindered the development of physiological maturity (PM) at harvest, and the use of mechanical grain harvesting (MGH). How to balance the drying characteristics of maize varieties and make full use of accumulated temperature resources is a difficult problem in reducing grain moisture content (GMC) at harvest. RESULTS The drying effective accumulated temperature (AcT, above 0°C) of different varieties was quite different, and the drying rate of maize varieties after PM treatment was between 17% and 29%, with an average of 23%. Under the condition of 25% GMC, the growth periods of fast drying variety (FDV) and slow drying variety (SDV) were 114-192 days and 110-188 days respectively. FDV and SDV must reach PM between the 30th , August and 9th , October. After PM, FDV and SDV need take 47 and 51 days to reduce GMC for MGH, respectively. Harvested at under the condition of 20% GMC, the growth periods of FDV and SDV were 97-175 and 90-171 days, respectively. The two types of varieties must reach PM between 10th , August and 19th , September. After PM, FDV and SDV need spend 64 and 70 days on reducing GMC for MGH, respectively. CONCLUSION Cultivar matching with AcT can relieve the negative impact of trans-regional planting and help farmers to choose suitable varieties. By promoting MGH, this result may boost maize production, thus ensuring China's food security. This article is protected by copyright. All rights reserved.