Desempenho agronômico, heterose e estabilidade fenotípica de genótipos de cebola

Abstract

The objective of this study was to evaluate the performance, heterosis and phenotypic stability of 50 genotypes of onion (a lineage and eight experimental hybrids of Baia group, 10 lineages and 22 experimental hybrids of Creole group, six open pollinated varieties and three commercial hybrids) in three crop seasons in Guarapuava, Paraná state, Brazil, in 2010/2011. Three experiments were carried out in randomized block design with three replications. Seedlings aging 45 days were transplanted on May 27, June 30 and August 03. We evaluated agronomic characteristics of bulbs. For the analysis of phenotypic stability of genotypes the method of Annicchiarico was used. We also estimated the heterosis of seven hybrids. The first period provided the highest values of average mass and increased yield of bulbs and the third period provided the lowest values. Only 26% of genotypes showed general confidence index (ωi) above 100% for bulb yield. The experimental hybrids HB1266, HB2285, HC3119, HC3126, HC3479 and HC3488 showed the highest confidence index for bulbs yield, although in the first period they did not participate in the group of highest yield genotypes. The mean of heterosis observed for the average mass of bulbs was 38%, ranging from 16% (HC3485) to 63% (hybrid HC3483) and for yield was 36%, ranging from 16% (HC3485) to 57% (HC3483).