Resumo -O objetivo deste trabalho foi avaliar, por meio de correlação genotípica e análise de trilha, as associações entre características em famílias de meios-irmãos de couve e os possíveis efeitos da seleção truncada. Foram avaliadas 13 características em 24 famílias de meios-irmãos de couve. Realizaram-se quatro análises de trilha, tendo-se considerado as seguintes variáveis básicas: altura de planta, número de brotações, número de folhas por planta e diâmetro do caule. Cada análise considerou 12 características como variáveis explicativas. Constataram-se as maiores estimativas de correlação entre as seguintes características: comprimento e largura do pecíolo; número de folhas; massa de matéria fresca de folhas; e comprimento e largura de folhas. A seleção quanto ao menor número de brotações ocasiona a redução do comprimento do pecíolo; quanto ao maior número de folhas, proporciona aumento da produção de massa de matéria fresca de folhas e redução da massa de matéria fresca por folha; e, quanto ao maior diâmetro do caule, ocasiona o aumento da produção de massa de folhas frescas. A seleção truncada quanto à altura de plantas não ocasiona alterações expressivas às demais características avaliadas.Termos para indexação: Brassica oleracea var. acephala, correlação genotípica, multicolinearidade, regressão em crista, seleção truncada. Genotypic correlation and path analysis of kale half-sib progeniesAbstract -The objective of this work was to evaluate the associations between traits in half-sib families of kale, through genotypic correlation and path analysis, and possible effects of truncated selection. Thirteen traits were evaluated in 24 half-sib families of kale. Four path analysis were carried out, considering the following basic variables: plant height, number of shoots, number of leaves per plant, and stem diameter. Each analysis included 12 traits as explicative variables. The highest estimates of correlation were found between the following traits: length and width of petioles; number of leaves; leaf fresh weight; and length and width of the leaves. The selection for the smallest number of shoots leads to a reduction of petiole length; for the highest number of leaves, selection provides the increase of leaf fresh weight and the reduction of fresh weight per leaf; and, for the largest stem diameter, selection causes the production increase of fresh leaf weight. The truncated selection for plant height does not cause significant changes in the other evaluated traits.

Kale has a long vegetative cycle, requiring a lot of labor, due to the need for tutoring, thinning and multiple harvests, leading to difficulties in the maintenance and evaluation of experiments. Thus, the objective was to estimate the minimum number of evaluations for the assertive selection of half-sib progenies of kale by means of a repeatability study by Bayesian approach. Twenty four half-sib progenies were evaluated in a randomized block design with four replicates and five plants per plot. The number of shoots, number of marketable leaves, fresh mass of marketable leaves and fresh mass per leaf were measured throughout 15 harvests. All traits showed high estimates of the repeatability, indicating high regularity in the expression of the traits during the harvesting period. With eight harvests it is possible to evaluate all the traits with a coefficient of determination superior to 85% in half-sib progenies of kale.