ABSTRACT. Grain size is an essential trait in common bean breeding as it determines the acceptance of a new cultivar by producers, consumers, and the industry. The objectives of this study were to identify the ideal traits for selecting common bean lines in the F3 generation to obtain an adequate sieve yield and to identify the best lines for sieve yield by applying early generation selection. Two trials were conducted in two locations during the 2016/2017 crop season. These trials were composed of 300 F3 populations and two parents (used as checks). The experimental design used was an augmented block design without repetition for the treatments (lineages). After harvest, the grain yield, yield components, and sieve yield (SY) were evaluated. In conclusion, selection in the F3 generation can be performed for sieve yield, considering the traits SY12+13, SY14, and relative grain yield, as they present the highest values of heritability and greatest correlation between genotype and performance in the evaluated environments. Additionally, the lines selected to continue in the breeding program are composed of the 15 best lineages for traits SY12+13, SY14, and relative grain yield. Preference should be given to lines that excel in more than one of these traits.

Resumen Con miras de afrontar la baja productividad en cultivos de fríjol (Phaseolus vulgaris L.) en el estado de Paraná, Brasil, esta investigación buscó evaluar el desempeño agronómico de diferentes genotipos de frijol cultivados en la segunda época de siembra empleando alto y bajo manejo tecnológico. El diseño experimental fue de bloques completamente al azar con tres repeticiones en esquema factorial triple del tipo 3x13x2, el Factor A estuvo constituido por tres años de cultivo (segunda época de siembra: 12/13; 13/14 y 14/15), el Factor B estuvo compuesto por 13 cultivares de frijol (BRS Campeiro; BRS Esplendor; IPR Gralha; IPR Tuiuiú; IPR Uirapuru; BRS Ametista; BRS Estilo; BRS Notável; BRS Pérola; IPR 81; IPR Campos Gerais; IPR Curió e IPR Tangará) y el Factor C, constituido por dos niveles de manejo tecnológico (alta y baja tecnología). El manejo de alta tecnologia, resultó en productividad de granos superior y estadísticamente distinta del manejo de baja tecnología en la segunda época de siembra: 12/13, 13/14 y 14/15, y en el promedio general de los tres años del cultivo de frijol. Por lo tanto, una mayor inversión en tecnología aumenta la probabilidad de aumento de la rentabilidad económica del produtor, debido al aumento en la productividad del cultivo de frijol. El cultivar BRS Pérola, presentó productividad de granos superior estadísticamente a los cultivares IPR Tuiuiú, IPR Gralha, IPR Campos Gerais, IPR Tangará, IPR Uirapuru, IPR 81 y IPR Curió, demostrando ser una buena opción para lograr una alta productividad.

Abstract In the face of bean (Phaseolus vulgaris L.) crops with low grain yield in Brazil, specifically in the state of Parana-Brazil, this research aimed to evaluate the agronomical performance of different genotypes grown in the second-season under high and low technology management. The experimental design was a randomized block design with three replications in a 3x13x2 triple factorial arrangement, where Factor A was composed of three years of cultivation (second-season 12/13, 13/14 and 14/15), Factor B consisted of 13 bean cultivars (BRS Campeiro; BRS Esplendor; IPR Gralha; IPR Tuiuiú; IPR Uirapuru; BRS Ametista; BRS Estilo; BRS Notável; BRS Pérola; IPR 81; IPR Campos Gerais; IPR Curió and IPR Tangará) and Factor C consisted of 2 levels of technological management (high and low technology). The use of high-technology management resulted in higher grain yield, statistically different from the low-technology management in the second-season 12/13, 13/14 and 14/15 and from the overall mean of the three years of cultivation. Thus, greater investment in technology increases the probability of increasing in economic profitability of the producer due to the growth in bean crop productivity. The cultivar BRS Pérola exhibited grain yield values statistically higher than cultivars IPR Tuiuiú, IPR Gralha, IPR Campos Gerais, IPR Tangará, IPR Uirapuru, IPR 81 and IPR Curió, proving to be a good choice to achieve high productivity.