Interação de genótipos por épocas de semeadura em couve-flor

Abstract

In order to test the performance of commercial and experimental cauliflower hybrids in response to sowing dates, a series of experiments were carried out over 12 months of the year 2012 at the HortiAgro Seeds, an Experiment Station located at the Palmital Farm in the Ijaci city MG-Brazil. The genotypes tested comprised 4 new experimental hybrids from HortiAgro Seeds [F1(CFX-001A x L-2943), F1(CFX-002A x L-2943), F1(CFX-004A x L-2943), F1(CFX-005-02A x L-2943)] and 7 commercial cauliflower hybrids, namely: the standard hybrids Barcelona-CMS (winter-adapted) and Verona-CMS (summer-adapted), both from Seminis Seeds; hybrids Julia, Sharon, Cindy and AF-2172 from Sakata Seeds, and the extra-early tropical hybrid Bianca, from HortiAgro. The experimental design comprised a factorial arrangement of 11 genotypes x 12 sowing dates (months). Each monthly trial was set up as a randomized complete block design with 3 replications. The traits evaluated were: Curd Quality Index (CQI), percent curds with acceptable quality, cycle (days from sowing date), curd diameter (cm) and curd mass (g). The genotype x sowing date (month) interaction was significant (alpha=0.05) for all traits under study. Based on the differential responses indicated by the genotype x month interaction, the hybrids could be assigned to three different groups: (a) summer-adapted (or tropical) hybrids: Verona-CMS, Cindy, Sharon and all four new HortiAgro hybrids; (b) winter-adapted hybrids Barcelona, Júlia and AF-2172; (c) the extra-early tropical hybrid Bianca. Three contrasting groups of sowing dates could be identified: (a) September to December (corresponding to harvest in full summer); (b) January to March (corresponding to harvests in autumn and early winter); (c) April to August (harvests in winter and spring). Among the HortiAgro experimental hybrids, F1 (CFX-005-02A x L-2943) showed the widest adaptation range, and heaviest (largest) curds. Winter-adapted hybrids Barcelona-CMS and AF-2172 were similar in performance, with slight advantage of AF-2172 relative weight, and slight advantage of Barcelona-CMS relative to adaptability range.