ABSTRACT: The average yield of sweet potato (Ipomoea batatas (L.) Lam.) in Brazil is below the crop potential, and appropriate cultural practices and more productive cultivars are needed to improve crop yield. The Beauregard sweet potato cultivar, originally from the United States, has shown high productive potential. This study evaluated the performance of features of agronomic importance of the Beauregard cultivar in comparison to local cultivars and eight sweet-potato clones in Brazilian regions. For that purpose, two sets of experiments were carried out. The first set evaluated eight sweet potato clones and cultivars Beauregard, Olho Roxo and Ourinhos in Brasília–DF and Itabaiana–SE using as criteria two foliage and six root traits. In the second set, two sweet potato clones (9 and 75), and Beauregard, Brazlândia Branca and Canadense cultivars were evaluated in Piacatú–SP, Brasília–DF, PAD–DF, Canoinhas–SC and Altamira–PA, for the traits: commercial, non-commercial, and total yield. Beauregard presented little foliage production but great root yield across the different environments. Since it has low dry matter content, acceptance of this cultivar may be limited in some regions. None of the sweet potato clones showed stable yield to justify a commercial launch.

O objetivo deste trabalho foi estimar parâmetros genéticos e avaliar a seleção simultânea quanto à produtividade de raízes e à adaptabilidade e estabilidade de genótipos de mandioca. Os efeitos dos genótipos foram considerados como fixos e aleatórios, e a metodologia de modelos mistos (REML/Blup) foi utilizada para estimar os parâmetros genéticos e a média harmônica do desempenho relativo dos valores genotípicos (MHPRVG), para seleção simultânea. Dez genótipos foram avaliados em delineamento de blocos ao acaso, com quatro repetições. O experimento foi realizado nos municípios de Altamira, Santarém e Santa Luzia do Pará, PA, nos anos agrícolas de 2009/2010, 2010/2011 e 2011/2012. As raízes foram colhidas 12 meses após o plantio, em todos os locais testados. A produtividade de raízes apresentou baixo coeficiente de variação genotípica (4,25%) e herdabilidade de parcelas individuais no sentido amplo (0,0424), o que resultou em baixo ganho genético. Em razão da baixa correlação genotípica (0,15), a classificação dos genótipos quanto à produtividade de raízes variou de acordo com o ambiente. Os genótipos CPATU 060, CPATU 229 e CPATU 404 destacaram-se quanto à produtividade, adaptabilidade e estabilidade.

The objective of this work was to estimate genetic parameters and to evaluate simultaneous selection for root yield and for adaptability and stability of cassava genotypes. The effects of genotypes were assumed as fixed and random, and the mixed model methodology (REML/Blup) was used to estimate genetic parameters and the harmonic mean of the relative performance of genotypic values (HMRPGV), for simultaneous selection purposes. Ten genotypes were analyzed in a complete randomized block design, with four replicates. The experiment was carried out in the municipalities of Altamira, Santarém, and Santa Luzia do Pará in the state of Pará, Brazil, in the growing seasons of 2009/2010, 2010/2011, and 2011/2012. Roots were harvested 12 months after planting, in all tested locations. Root yield had low coefficients of genotypic variation (4.25%) and broad-sense heritability of individual plots (0.0424), which resulted in low genetic gain. Due to the low genotypic correlation (0.15), genotype classification as to root yield varied according to the environment. Genotypes CPATU 060, CPATU 229, and CPATU 404 stood out as to their yield, adaptability, and stability.