TDZ aumenta frutificação efetiva em ameixeira ‘Laetitia’

‘Laetitia’ is the main plum cultivated in Santa Catarina state, Southern Brazil. A key challenge to increasing the productivity of plums in this region is the low fruit set. This study aimed to evaluate the effect of Thidiazuron (TDZ) application on fruit set, size ripeness at harvest and post-harvest quality conservation of ‘Laetitia’ plums. The experiment was conducted in a commercial orchard in Urubici, SC, during harvest 2024/2025. TDZ was applied to the plum trees during flowering at concentrations of 0, 15, and 30mg L⁻¹. Fruit set, fruit maturation and, quality were evaluated at harvest and after storage. Results showed an increase in fruit set of ‘Laetitia’ plum trees with higher TDZ doses. Untreated fruits had lower pulp firmness at harvest; however, after the storage period, fruits treated with 30mg L-1 of TDZ presented the lowest values. No significant differences were found in fruit weight, soluble solids, titratable acidity, and flesh browning, which was the main physiological disorder. In conclusion, the application of TDZ during flowering has the potential to increase fruit set in plum trees.