During winter season, the apple trees show no growth due the bud dormancy. In the north of Parana State, where the cold is not sufficient to provide the natural bud break of apples, it is necessary to use chemical products to induce the growth of these plants. The objective of this research was to compare different concentrations of hydrogen cyanamide, associate to mineral oil, regarding the bud break of 'Eva' apple cultivated in Londrina region. Five concentrations of hydrogen cyanamide (0.00%; 0.25%; 0.50%; 0.75% and 1.00%), associated to mineral oil (3%) were studied. The porcentage of lateral and terminal burst bud was evaluated as well as the relation between the number of fruits and the number of burst buds per branch of each treatment. It was possible to conclude that hydrogen cianamide at 0.50%+mineral oil 3% was the best concentration to improve the efficiency of bud growing and fruit set of 'Eva' apple cultivated in Londrina region.
Malus domestica; apple tree; hydrogen cyanamide
