Evaluation of different orange maturation curves by means of cluster analysis

Fruit maturation of seventeen sweet orange clones and cultivars were evalua ted by cluster analysis. Soluble solids (degrees Brix) and acidity were det ermined during the spring season 1995, in Cordeiropolis, SP, Brazil, Polyno mial equations were determined between August and December and values for t hose variables were estimated 70, 75, 80, 85 and 90 days after the initial fruit sampling. The data set was standardized to perform cluster analysis r egarding the Euclidean distance measure and the linkage rule as UPGMA type. Four clusters were selected in regard to fruit maturation stage. Navelenci a, the earliest clone, showed 13.4 degrees Brix and 0.83% acidity in the be ginning of the considered period. The Pera cultivar, another single clone c luster, showed ratio higher than 12.0 after middle October. The Natal, Folh a Murcha, Old Bud Line, Cutter, Valencia, Lue Ging Gong and Tuxpan orange c lones and cultivars formed a third cluster, which reached harvesting maturi ty during middle November, whereas, Frost, Whits, Olinda, Late, Stone, Chaf fei, Werley and Berry clones reached the same stage forty days later.