Abstract: To explore the effects of different drought conditions at different growth stages on the yield and grain quality of spring maize, a comparative experiment of moderate and severe drought stress was conducted using cultivar Danyu 405 to analyze the effects of drought on maize yield and structural traits, grain water content, and quality composition at three key growth stages (jointing, tasseling, and milking stages) of spring maize. The results showed that drought significantly increased maize bald tip ratio, grain amino acid, and crude protein content by 85.3%, 10.6%, and 14.9% respectively. Drought significantly decreased 100kernel weight, theoretical yield, grain water content, and starch content by 14.2%, 30.5%, 29.7%, and 45.2% respectively. Drought had minor effects on ear length, ear thickness, and grain fat content. Grain starch content was most sensitive to drought during jointing stage. Ear thickness, bald tip ratio, grain water content, fat content, and amino acid content were most affected by drought during tasseling stage, while ear length, 100grain weight, yield, and grain crude protein content were most affected by drought during milking stage. With the increases of drought degree, the yield and grain quality of maize were affected more, with the effects on grain quality being more significant than that on yield. Our results lay a foundation for future high-yield and high-quality maize production and provide an important theoretical basis for understanding the mechanism underlying the responses of agricultural production to climate change.

Key words: spring maize, drought stress, yield, quality.