The objective of this research was to evaluate peach and nectarine varieties, selection, and yield in the Planalto Médio Region of the State of Rio Grande do Sul, Brazil. A total of twelve peach cultivars and nine selections; two nectarine cultivars and one selection, with required temperature lower than 7,2 ºC, raging from 150 and 400 hours, were evaluated. These studies were carried out in the 1997/98, 1998/99 and 1999/00 growing seasons. The experimental fruit trees consisted of three plants from each cultivar, which were grown at 6 x 3 m from each other, conducted according to an open vase shape, and without irrigation. In 1997, the plants were at the beginning of the sixth growth cycle. The results for three grown seasons (1997/98, 1998/99, 1999/00) showed that the anticipation of blooming also caused up an anticipation of 20 days in the harvest time. This effect was variety or selection dependent and it was a result of the higher temperatures in late June and during July. Several fruit tree cultivars and selections provided yields above 15 t ha-1. Although peach cultivars Chimarrita, Marli and Eldorado are already widely grown in the Planalto Médio region, more studies are necessary to indicate the best materials, especially because of the weather conditions that ocurred in the last three seasons which were different from normal.
Prunus persica; cultivars; harvest
