Multi-year progeny test identifies superior progenies and a biennial yield pattern in macaw palm (Acrocomia aculeata)

The macaw palm ( Acrocomia aculeata ) is a native Neotropical palm with potential for vegetable oil production, particularly for biofuel generation. However, its domestication remains incipient, and information on long-term progeny performance is still limited. This study evaluated fruit yield and biennial bearing in a macaw palm progeny test to identify superior families for genetic improvement. Thirty-six half-sib progenies from two regions of Minas Gerais, Brazil, were assessed for fruit production from 2019 to 2024 at the Federal University of Viçosa, Minas Gerais. The experiment followed a randomized complete block design with three blocks and three plots per block. Genetic variances, parameters, and progeny performance were estimated using mixed linear models (REML/BLUP) implemented in the ASReml package in R. Biennial bearing was identified based on multi-year yield patterns and phenotypic correlations among consecutive and alternating production cycles. Mean fruit production ranged from 1.34 kg plant⁻¹ in 2019 to 26.32 kg plant⁻¹ in 2022. Most of the genetic variability for yield was concentrated within progenies, with a broad-sense heritability of 0.36, indicating high intrafamilial heterogeneity. Four of the evaluated progenies stood out for their superior performance, year-to-year stability, and, in some cases, early flowering. Intrafamilial selection within these progenies, totaling eight individuals, increased the population mean yield by 30.12%. A pattern of negative biennial bearing was observed, reinforcing the importance of multi-year evaluations for accurate selection, with no association with accumulated annual precipitation. The selected progenies are promising candidates for directed crosses and may contribute to advances in macaw palm breeding programs.