Hungarian sweet maize production, in demand worldwide, averages 500,000 tonnes over several years, thanks to well-chosen precision farming technology. In agriculture, the success of sweet maize production is influenced by many factors, and therefore we are constantly faced with practical challenges. Limited data are available on the dynamics of sugar accumulation in plants, especially under abiotic stress. We investigated a sweet maize hybrid for public cultivation in an experiment set up on the campus of the University of Debrecen, Faculty of Agricultural and Food Sciences and Environmental Management. Quality parameters were determined from grain samples taken at harvest under laboratory conditions at the Agricultural Instrument Centre of the Faculty. In our sweet maize field experiment, dry matter content and sucrose content were measured in grain samples taken at four sampling times. Based on our measurement results, we found that the dry matter gain dynamics of the four examined sweet maize hybrids were different, all with linear increasing trends. Based on our research results, we demonstrated that dry matter and sucrose yields of all four hybrids were most favourable for harvesting at the third sampling time. Compared to the first sampling date, in two weeks, dry matter yield increased by 46% and sucrose content tripled in a tonne of sweet maize grain yield. Thereafter, dry matter and sucrose gains slowed down.