Peach production has experienced a significant increase in the regions where the climate presents a mild winter. Determining the correct time of fruit pruning is fundamental to improve the fruit quality. The correct time for fruit pruning can be defined through the knowledge of the curve of fruit growth. Fruit growth, fresh weight (PV) and dry weight (PS) of 20 peach varieties had been evaluated at Epagri's Agriculture Research Station of Urussanga, State of Santa Catarina, Brazil (latitude 28º31'S, altitude 48 m). The plants had been grouped in varieties of short, medium and long cycle, related to the period from budding to fruit harvest, ranging from W77 to 85 days, 86 to 109 days and more than 109 days, respectively. Weekly, from blossom to harvest, green fruits have been harvested, then weighed (PV) and dehydrated in a stove at 70ºC to determine the PS. All the varieties had presented a very high initial relative growth (PS daily gain / PS total of the fruit), which was reducing until the maturation of the fruits for the varieties of short and medium cycle. However, the long cycle varieties had an increase on the relative growth in the end of the cycle. Long cycle varieties presented three stages of fruit growth, considering the PS, PV and the daily accumulation of PS and PV: Stage I, with exponential growth; Stage II, with little growth; Stage III, with exponential growth culminating with the fruit maturation. On the other hand, varieties of medium and short cycle had not presented the Stage II, with little growth, switching directly from Stage I to Stage III.
Prunus persica; fruit growth; production; ecophysiology; physiology; quality
