The production of ' Rosada Niagara ' in tropical and subtropical regions of Brazil has been problematic, mainly due difficulty of emission and development of sprout after the yield pruning carried out in the months of occurrence of lowers temperatures, what it has caused reduction in yields and discourage of farmers. Three experiments was carried out to try to solve this problem, in commercial orchards located in northwest region of the State of São Paulo, with the objective of verify the effect of ethephon, applied before the yield pruning, in the defoliation of the plant; in the emission and development of the sprout and in the duration of the period of pruning until the flowering. Four levels of Ethephon (0, 3, 6 and 9 L.ha-1) applied by foliar way had been tested 15 days before the yield pruning, carried out in June of 2001. It was observed in the present work, that the ethephon even though didn't cause significant effect in the sprouted bud number, in the development of the sprout caused an increase of these variable, when applied in little foliage orchards and mild climatic conditions. With relation to the defoliation of the plants, the best result had been observed in levels of 6 and 9L.ha-1.
Grape; growth regulator; sprout; defoliation; Vitis labrusca
