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Item Sample size estimation of fruit maturation for Arabica’s coffee(Instituto Agronômico (IAC), 2025-01-31) Botega, Gustavo Pucci; Abrahão, Juliana Costa de Rezende; Botelho, Thiago Tavares; Botelho, Cesar Elias; Salvador, Guilherme Soares; Gonçalves, Flávia Maria AvelarThis study aimed at establishing the ideal sample size for evaluating the maturation cycle in Coffea arabica, and investigating the errors associated with different sample sizes, in addition to verifying the possibility of using the clustering method to separate genotypes according to the maturation stage. Two experiments were analyzed: one with F2:3 progenies using visual maturation assessment through fruit counting, and another with cultivars using image processing for maturation assessment. To determine the ideal sample size for this trait, we used the estimation of the errors associated with maturation, using the bootstrap technique. Subsequently, the K-means algorithm was tested as an alternative for clustering genotypes into maturation classes. The application of the bootstrap technique in order to estimate the error associated with maturation revealed that the adoption of a 450-mL sample size resulted in an associated error of approximately 5%, indicating that it is an adequate size for character assessment. The implementation of K-means as a clustering tool offers a promising perspective for Arabica coffee plant breeding programs. A more comprehensive analysis, which not only assesses the proportion of ripe fruits, but also considers the distribution of different maturation stages, provides a more accurate understanding of the maturation process. This allows a more precise identification of genotypes with the most suitable performance for different growing conditions, as well as enabling adjustments in harvest management and post-harvest processing, optimizing coffee quality.Item Desempenho agronômico de cultivares de café resistentes à ferrugem no Estado de Minas Gerais, Brasil(Instituto Agronômico (IAC), 2012-10) Carvalho, Alex Mendonça de; Mendes, Antônio Nazareno Guimarães; Botelho, Cesar Elias; Oliveira, Antonio Carlos Baião de; Rezende, Juliana Costa de; Rezende, Ramiro MachadoObjetivou-se no trabalho avaliar o comportamento de 24 cultivares de cafeeiro, sendo 22 resistentes à ferrugem e duas testemunhas suscetíveis, em diferentes ambientes de Minas Gerais, a fim de contribuir para a recomendação técnica. Os experimentos foram instalados em quatro municípios (Lavras, Campos Altos, Patrocínio e Turmalina). O delineamento experimental utilizado foi o de blocos casualizados com três repetições, no espaçamento de 3,5x0,7 m e parcelas de dez plantas. As avaliações de produtividade, porcentagem de grãos classificados em peneira 16 acima e vigor vegetativo referem-se a quatro colheitas (2008 a 2012). Foram avaliadas, também, a adaptabilidade e estabilidade da produtividade das cultivares. As cultivares Sabiá Tardio, Pau Brasil MG1, Obatã IAC 1669-20, Catucaí Amarelo 24/137 e IPR 103 são promissoras para as referidas regiões cafeeiras. Essas cultivares aliam estabilidade e adaptabilidade independentemente do ambiente, com desempenho agronômico superior.