Respuesta de manzanos 'Rosy Glow' a la poda mecánica en verde

The apple tree is the main deciduous crop in Uruguay. In recent years the interest of producers to export has increased, however, the high annual climatic variability, together with the shortage of labor have led to adapting new technologies that can lift these restrictions. Thus, mechanical pruning emerges as an option to be evaluated. Therefore, the objective of the thesis is to evaluate the effect of mechanical green pruning on light interception, plant development, production and the quality of the fruit produced in the cultivar 'Rosy Glow'. For this, a commercial establishment was selected in the area of ​​Canelones, Uruguay in the 2019-20 harvest. Crips Pink ‘Rosy Glow’ trees were used on M9, arranged in a randomized complete block design. The evaluated treatments were: Control without pruning (SP), pruning at 12 leaves (P1), pruning at 20 leaves (P2), and pruning at 12 and 20 leaves (P12). Within the experiment, toast length, PAR radiation, yield, overcolor percentage, color analysis, soluble solids, pulp firmness, fruit diameter and weight were evaluated. Among the main results obtained, it stands out that the SP treatment (without pruning) presented the highest interception of light, with a yield of 'Pink Lady' quality fruit (depending on the overcolor) 25% lower than the pruned treatments. Regarding the fruit quality parameters: TSS, pulp firmness and fruit weight did not differ between treatments, on any of the harvest dates. Treatments with mechanical pruning at twelve leaves (treatments P1 and P12) reduced the number of fruits per plant as a consequence of pruning, decreasing the number of manually thinned fruits. The pruning carried out on the second date (20 leaves) did not provoke responses in the growth of toast, nor in the number of fruits. In conclusion, the present work constitutes one of the first evaluations of mechanical pruning in the conditions of southern Uruguay and presents promising results. More years of study and evaluations of the effect on the next productive cycle are necessary to make more conclusive considerations about the use of this technology.