Agroclimatic interactions influencing maturity of Virginia-type peanuts in humid subtropical environments: Toward sustainable peanut production

Understanding peanut maturity dynamics is critical to optimizing harvest timing, maximizing yield and kernel quality, and improving production sustainability. However, quantitative evaluations of maturity progression in Virginia (VA)-type cultivars remain limited under humid subtropical environments. This limitation is further complicated by the belowground and indeterminate nature of peanut pod development, which makes direct field assessment of maturity difficult and labor-intensive. This study presents a comprehensive multi-environment evaluation of peanut maturity dynamics of five VA-type cultivars (Bailey-II, Emery, Walton, NC-20, and Sullivan) using datasets from agronomic research trials, breeder seed trials, and commercial grower fields across VA and North Carolina in 2022–2024. 1,162 field samples were collected through systematic pod sampling, and their maturity was determined using the pod blasting followed by mesocarp color classification (white to black). A Peanut Maturity Index ( PMI ), calculated as the proportion of orange, brown, and black pods relative to total pods, was used to quantify maturity. Days after planting ( DAP ) was the dominant driver of maturity development ( p < 0.001), with steady increases through 120 DAP and accelerated maturation between 140 and 160 DAP . Optimal maturity ( PMI = 0.65–0.75) occurred at 140–150 DAP for Bailey-II, Emery, Sullivan, and NC-20, whereas Walton matured at the last (145–155 DAP ). Significant genotype × environment interactions were detected, while the growth regulator effect was inconsistent. Comprehensive growing degree day ( GDD ) computations provided more evidence with Bailey-II showing the strongest correlations ( r = 0.43–0.93), followed by NC-20, Emery, and Sullivan, while Walton exhibited the weakest and most variable relationships, reflecting greater environmental sensitivity. These results provide one of the most extensive multiyear, multi-location quantifications of VA-type peanut maturity under subtropical production, offering data-driven insights to refine cultivar selection, improve harvest scheduling, and support sustainable peanut production.