Avaliação biológica de estruturas florais em macieira e sua relação com a qualidade do fruto

Abstract

The apple tree is characterized by the different floral structures. Several researches show a relationship between the production and fruit quality and the original fruiting structure. The aim of this study was to evaluate the relationship between the floral structure and the fruit quality in the cultivars Gala, Fuji and Daiane in the mild climatic conditions in the south of Brazil. Six types of fruiting structures were characterized according to their nature and the bud size: spur of weak bud and spur of vigorous bud, short twig of terminal growth of weak bud and short twig of terminal growth of vigorous bud and long twig of terminal growth of weak spur and vigorous spur. For these different structures, were evaluated characteristics related to the phenological development, like the average dates of each phenological state and the percentage of buds that reached the different phenological phases. Patterns related to the productive potential and the fruit quality were evaluated, like the sprout and fruit set index, bud abortion index and percentage of vegetative buds, leaf area, number of flower per cluster and the length / diameter ratio of the fruits. In Gala and Fuji cultivars, the long twigs had the earlier phenological development and in Daiane, the earlier structure to sprout were the spurs. But in the three cultivars the highest percentage of buds in each phenological phase were found in the long twigs. The long twigs showed the highest sprout and fruit set index, as well as the major number of flowers per cluster and leaf area in the three cultivars, while the spurs showed the lowest results. The highest bud abortion index was found in the spurs and the lowest in the long twigs. According to the data found for the fruit shape, no difference was found in the cultivars Gala and Fuji. In the cultivar Daiane, however, the fruits with the highest length / diameter ratio were found in the long twigs.