This paper reports the effect of three different dates of severe pruning on floral differentiation of peach trees of the cultivars Tropical and Aurora-2, conducted on a meadow orchards system. The peach trees were pruned in 1986, at the 30th day of September, October and November. The experimental plots were located at the Experiment Station of Jundiaí, (23º08'S), Instituto Agronômico de Campinas, State of São Paulo, Brazil. The lateral buds of the peach tree branches were first collected for analysis at the 30th day after pruning and on a monthly basis afterwards. Through histological studies made on longitudinal sections of the buds, it was observed that the severe pruning of September 30th, did not change the peach tree reproductive development The floral differentiation began in February, i. e., five months after pruning and produced sequentially: the petals, sepals, stamens and pistil. In the other severe pruning dates, the floral differentiation was reduced, decreasing the flower-buds quantity. In the control peach trees, without severe pruning, the floral organogenesis normally occurred from January to March. The floral induction began, probably, in early summer (December) and persisted until fall (April).
peach; drastic pruning; high-density; flower-bud; reproduction; floral induction; blooming; subtropical climate