Yield determination of temperate maize hybrids with different end‐uses: An ecophysiological analysis

Abstract

Maize (Zea mays L.) production in Argentina changed markedly during the lastdecade due to the widespread adoption of late sowing dates, expanding its productivearea, and diversifying crop end-uses. This study was conducted to assess how thesowing date and nitrogen (N) availability affect grain yield, its physiological determinants(biomass and its partitioning), and numeric components (kernel number andkernel weight) of maize hybrids marketed for different end-uses. Field experimentswere conducted in two growing seasons (2019–2020 and 2020–2021) and two sowingdates within each season (early and late) at a site in the main maize-producingregion of Argentina. Within each season × sowing date combination, eight commercialmaize hybrids (commercialized as grain, dual-purpose, or silage) were testedunder two N levels (N0: no N applied; N250: fertilized with 250 kg N ha−1). Thegreatest grain yield, biomass, kernel number, and harvest index corresponded to thegrain hybrids. Dual-purpose hybrids showed an intermediate grain yield, the highest kernel weight, and a more “silage” than “graniferous” behavior. Silage hybrids hadimproved light interception up to silking + 15 days (R2) but exhibited the lowest grainyield. Differences in end-use steered crop breeding efforts toward different physiologicalstrategies. The improved understanding of the physiological mechanismsunderlying the productivity among maize hybrids with varying end-uses will assistin the selection and management of suitable cultivars to be grown under different systemsand environmental variations associated with an extended sowing date period.