Abstract:

Seven main sweet maize varieties in China were used as research materials, and six harvesting periods were set up at 15, 18, 21, 24, 27 and 30 d after pollination to study the effect of different harvesting periods on the quality traits of sweet maize. The water content, pericarp thickness and sugar composition in sweet corn were monitored dynamically. The results showed that: (1) grain moisture content of the tested sweet maize varieties decreased at 15-30 d after pollination, the change ranging from 80.09% to 68.76%; the grain water content of ‘Jingketian 608’, ‘Jingketian 533’ and ‘Zhongnongdatian 413’ decreased slowly; (2) the pericarp thickness of sweet maize varieties increased first and then decreased with the time after pollination, and the peak appeared about 21 days after pollination; the average pericarp thickness of ‘Zhongnongdatian 413’ was the highest among the tested varieties, 91.63 μm, and that of ‘Jingketian 608’ and ‘Mige’ were the lowest, 78.40 μm; (3) the content of glucose and fructose in the grains decreased at 15-30 d after pollination, the content of glucose and fructose of ‘Jingketian 533’, ‘Jingketian 183’ and ‘Jingketian 608’ were relatively high at 15-24 d after pollination; the sucrose and sorbitol content increased first and then decreased with the time after the pollination, the sucrose content of ‘Jingketian 158’ and ‘Mige’ were relatively high among different varieties at 21-30 d after pollination. At the grain early development stage (before 21 days after pollination), fructose and glucose were the main sugars in grains, and then sucrose gradually increased. Among different varieties, the total sugar content of ‘Jingketian 533’, ‘Jingketian 183’, ‘Zhongnongdatian 413’ and ‘Jingketian 608’ were higher than that of ‘Mige’. The main sugar components were fructose and glucose, while the sucrose content was relatively low.

Key words: harvest date, sweet maize, quality traits, sugar component, water content