Methods for selecting peach cultivars in the tropics

Abstract

The objective of the present study was the selection of peach cultivars with greater adaptability and production stability for the tropics through multivariate analysis. A randomized plot design with 17 cultivars (‘Aurora-1’; ‘Biuti’; ‘Centenário’; ‘Delicioso Precoce’; ‘Diamante’; ‘Doçura-2’; ‘Douradão’; ‘Dourado-2’; ‘Flordaprince’; ‘Jóia-3’; ‘Kampai’, ‘Libra’; ‘Maravilha’; ‘Okinawa’; ‘Ouromel-4’; ‘Régis’ and ‘Tropical’) was evaluated from 2013 to 2016. The following variables were evaluated during the production cycle each year: the average date for the beginning of harvest (BH), the phenotypic values for the period between pruning and the beginning of harvest (development cycle, DC), the number of fruits per tree (NF), the accumulated production (P. kg. tree−1) and the estimated accumulated productivity (P. t. ha−1). The fruit length (L) and fruit diameter (D) were measured (mm) in addition to the fruit mass (FM) and stone mass (SM) in grams (g). The ratio between the soluble solids and titratable acidity (SS/TA) was also calculated. To evaluate the multivariate analysis by the cluster analysis method, the cultivars were grouped into three different groups for the Tocher and canonical variables and two groups for the UPGMA method (unweighted pair group method using arithmetic averages). Among the studied variables, DC and P. t. ha−1 were for adaptability and stability performance, and ‘Kampai’ had general adaptability and the highest stability for DC and P. t. ha−1. By the analysis of the selection index, the best cultivars were ‘Aurora-1’, ‘Centenário’, ‘Douradão’, ‘Kampai’ and ‘Régis’. The cultivars ‘Aurora-1’, ‘Douradão’, ‘Kampai’ and ‘Régis’ were the most adaptable and stable regarding precocity and productivity for peach production in the tropics.