Phenology, productivity, fruit size, outer fruit, inner fruit, and vigor traits in an apple reference population

This dataset contains the phenotypic data of the apple REFPOP multisite trial. The apple REFPOP (reference population) is made of 534 genotypes, split into two groups: an accession group, involving 269 accessions of European and non-European origin representing the diversity in cultivated apple, and a progeny group, comprising 265 genotypes, which stemmed from 27 parental combinations. The population was planted in six locations in 2016, with two or four trees of each genotype/accession per location. The six locations were (i) Rillaar, Belgium, (ii) Angers, France, (iii) Laimburg, Italy, (iv) Skierniewice, Poland, (v) Lleida, Spain and (vi) Wädenswil, Switzerland. Thirty traits related to phenology, productivity, fruit size, outer fruit, inner fruit, and vigor were evaluated at up to six locations, during up to three seasons (2018-2020). Trunk diameter was measured in 2017 in some locations, enabling for a trunk increment calculation for 2018. Data for all traits were used in the paper by Jung et al. (2022) "Genetic architecture and genomic predictive ability of apple quantitative traits across environments" and are published in version 2 of the dataset. Data for harvest date, fruit overcolor, fruit weight and fruit number, were used in the paper by Cazenave et al. (2021) "Combining genetic resources and elite material populations to improve the accuracy of genomic prediction in apple" (see Metadata for complete reference) and were made available in the first version of the dataset.