-The objective of this work was to evaluate the effect of prohexadione calcium (P-Ca) and root pruning (RP) on the control of the vegetative growth and on fruit production and quality of 'Shinseiki' pear trees, under the climatic conditions of Southern Brazil. The experiment was conducted during the 2013/2014 and 2014/2015 crop seasons, in a 15-year-old orchard of 'Shinseiki' pear trees, trained to a central-leader system, with a 2x5 m spacing between plants, grafted onto Pyrus calleryana rootstock. The experiment was carried out in a randomized complete block design, with six treatments and four replicate. The treatments consisted of the control (without P-Ca application or RP), two P-Ca rates (300 and 600 mg L -1 ), two root pruning intensities (performed on one or on both sides of the tree), and root pruning on one side + 300 mg L -1 P-Ca. P-Ca reduced vegetative growth more effectively than RP, in both crop seasons, and the combination of both techniques did not result in additional control of the vegetative growth, compared with P-Ca alone. Vegetative growth was not affected by increasing the rates of P-Ca. The highest P-Ca dose negativelly affected fruit yield. Regarding fruit quality, RP increases the total soluble solids content at harvest.Index terms: Pyrus pyrifolia, fruit quality, growth regulators, high-density orchard, vegetative vigor, yield components. Controle do crescimento vegetativo de pereiras 'Shinseiki' por prohexadiona de cálcio e poda de raizResumo -O objetivo deste trabalho foi avaliar o efeito da prohexadiona de cálcio (P-Ca) e da poda de raiz (PR) no controle do crescimento vegetativo e na produção e na qualidade dos frutos de pereiras 'Shinseiki', sob condições climáticas do Sul do Brasil. O experimento foi realizado durante as safras de 2013/2014 e 2014/2015, em pomar de pereiras 'Shinseiki' com 15 anos de idade, conduzido em líder central, com espaçamento de 2x5 m entre plantas, enxertadas em porta-enxerto Pyrus calleryana. O experimento foi realizado em blocos ao acaso, com seis tratamentos e quatro repetições. Os tratamentos consistiram na testemunha (sem aplicação de P-Ca e sem PR), em duas doses de P-Ca (300 e 600 mg L -1 ), em duas intensidades de poda de raiz (realizada em um ou nos dois lados da planta) e na poda de raiz em um lado da planta + 300 mg L -1 de P-Ca. A P-Ca reduziu o crescimento vegetativo mais efetivamente do que a PR, em ambas as safras, e a combinação de ambas as técnicas não resultou em controle adicional do crescimento vegetativo, em comparação à P-Ca utilizada sozinha. O crescimento vegetativo não foi influenciado pelo incremento nas doses de P-Ca. A maior dose de P-Ca afetou negativamente a produtividade de frutos. Quanto à qualidade de frutos, a PR aumenta o teor de sólidos solúveis totais na colheita.Termos para indexação: Pyrus pyrifolia, qualidade de fruto, fitorreguladores, pomar adensado, vigor vegetativo, componentes da produção.

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Nowadays, despite of being a typically temperate fruit crop, peach is found in subtropical and even tropical altitude zones, due to breeding efforts. Genetic knowledge and phenotypic and environmental parameters directly or indirectly influence the characters of economic importance in peach, and they are of great importance for breeding programs orientation. The aim of this study was to estimate heritability of a color shade character of peach flesh, measured by the Hue angle, chroma and lightness to evaluate its distribution in the populations, testing the possible existence of maternal effect. Results showed that parameters related to color shade of peach flesh have a medium heritability. Parents selection based on phenotype allows a medium genetic improvement for the mentioned character. This heritability is predominantly additive, without maternal effect. The Hue angle is the correct parameter to be used to classify and study yellow-flesh peaches and nectarines in relation to their color shade. However, the multivariate analysis of principal components, using the three parameters Hue angle, chroma and lightness, is an alternative of high accuracy.

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