Cytokinin- and Auxin-Based Plant Growth Regulators (PGRs) are commonly employed to increase fruit size due to their ability to modulate cellular structure. This study aimed to evaluate the effects of different PGR application protocols on histological parameters, yield components, and fruit quality in ‘Maxi Gala’ apple. The experiments were carried out under humid subtropical conditions of southern Brazil across two growing seasons (2021/22 and 2022/23), allowing comparison of treatment performance under distinct climatic patterns. Data from common treatments were combined across years for integrated analysis. The PGRs used included 6-benzyladenine (BA) as a cytokinin source; naphthalene acetic acid (NAA) as an auxin source; and tryptophan, a precursor of auxin biosynthesis. PGRs were applied in various combinations and concentrations between 10 days after dormancy break (BBCH 01) and fruit diameters of 25–27 mm (BBCH 74), following a randomized block design with four replicates of twelve trees each. The multivariate analysis of treatments was performed using Principal Component Analysis (PCA). Additionally, an analysis of variance was performed for flesh firmness loss, with means compared using Tukey’s test (p < 0.05). PGRs significantly influenced only the histological parameters of the fruit flesh tissues. BA and tryptophan had the greatest effects on cell size and cell number in the fruit flesh, respectively, both reducing intercellular spaces. Tryptophan was associated with a higher number of smaller cells, whereas NAA promoted larger cell sizes. The combination of BA and NAA, as well as a single application of BA at petal fall, resulted in the highest yield performances and increased the proportion of large fruits. Furthermore, BA enhanced the percentage of red skin coloration and improved flesh firmness during storage.

This study aimed to evaluate the vegetative, productive, and fruit quality parameters of the European pear cultivars ‘Rocha’ and ‘Santa Maria’ under the training systems of Tall Spindle, with branches bent at an angle of 45° (Tall Spindle—45°) and 90° (Tall Spindle—90°) to the leader, and Bi-axis. The evaluation was conducted over the 2016/2017 to 2022/2023 growing seasons in the highland region of southern Brazil. Both Tall Spindle systems significantly improved the yield and productive efficiency compared to the Bi-axis system, with ‘Santa Maria’ showing superior performance under Tall Spindle—90°. While ‘Rocha’ exhibited no significant differences between Tall Spindle systems, it benefited from better vigor control and reduced biennial bearing when trained under the Bi-axis system. Fruit quality parameters were consistent across training systems, indicating Tall Spindle—90° as an optimal choice for productivity and stability in ‘Santa Maria’. These results emphasize the adaptability and efficiency of training systems for pear orchard management.

The objective of this study was to evaluate the agronomic performance of the Geneva® series apple rootstocks G.202, G.213, G.210 and G.814. The rootstock G.202 and G.213 proved to be the less vigorous, being considered dwarfs. For replanting soil, ‘G.210’ was considered an efficient alternative. The ‘G.213’ was the most efficient, in a general point of view, demonstrating that it does not change its yield efficiency and stability characteristics, even under replanting conditions. All rootstocks reached the goal of 120 accumulated tons.ha-1 in Caxias do Sul-RS, highlighting the faster financial return to the growers. ‘G.213’ has higher soluble solids content, indicating the possibility of an earlier harvesting. It is concluded that the G.210 and G. 213 rootstocks are good options for the areas evaluated, under replanting conditions, mainly G.213 for more dense systems and G.210 for areas under extreme replanting conditions.