The ideal harvest time for seed production in maize (Zea mays L.) varieties of different maturity groups

BACKGROUND: The correct time for harvesting is a key factor contributing to the production of high-quality maize seeds. We conducted field experiments to harvest seeds at 11 developmental stages for 3 years, to investigate seed vigor traits in three early maturity maize varieties and two late maturity varieties in one location. RESULTS: Significant correlations (r = 0.72 similar to 0.89) were found among six seed-related traits: standard germination (SG), accelerated aging germination (AAG), cold test germination (CTG), hundred-seed weight (HSW), seed moisture content (SMC), and >= 10 degrees C accumulated temperature from pollination to harvest (AT10). Analysis of variance showed that harvest stage, year, and variety had significant effects on all traits, and harvest stage displayed the greatest effect. The responses of SG, AAG, CTG, HSW and SMC to harvest stage fitted quadratic models, and AT10 fitted a linear model. From the quadratic models, an ideal harvest time (IHT, the final date to reach maximum SG, AAG, and CTG) could be calculated for each variety. The three early maturity varieties reached their IHT at 54.94-58.44 days after pollination (DAP); the two later maturity varieties reached IHT several days later (at 59.87-59.90 DAP). The early maturity varieties consistently required less AT10 to reach the IHT than the later maturity varieties. However, all of the varieties reached the IHT at similar SMC levels of about 35%. CONCLUSION: The later maturity varieties reached the IHT at later DAPS when they acquired more AT10 than the early maturity varieties but both reached it at similar SMC levels. (C) 2022 Society of Chemical Industry.