BREEDING OF TEMPERATE ZONE FRUITS FOR SUB-TROPICAL CONDITIONS

The temperate fruit production in Brazil is located between 23 and 33°S. Most of the orchards are located at altitudes from 500 to 1400 m. Over the great majority of the area there is a mild winter, where chilling varies between 150 to 900 h below 7.2°C. The summer is hot and wet, with an annual rainfall above 1500 mm, causing serious problems with summer diseases. The main objectives of the apple breeding program is to develop low chill varieties with resistance to the main diseases (scab: vertical Vf resistance; Gala leaf spot also vertical resistance; horizontal mildew resistance and bitter rot resistance, all recently initiated work. The Brazilian market has preference for red-striped skin color of fruits, like ‘Gala’ and sweet flavor, like ‘Fuji’ as references. These are the patterns used in the selection of new varieties in Brazil. The long vegetative period at Southern Brazil allows an extended harvesting period from the current 2.5 months up to 4.5 months. Besides fruit quality and high productivity as inherent objectives of each of the world peach breeding programs, in Southern Brazil the emphasis is given to climatic adaptation for low chilling areas, tolerance to pronounced temperature oscillations and no excessive early blooming in order to avoid problems with late winter frosts. Resistance to brown rot and bacterial diseases, and fruits of a high total soluble solid content are the main priorities of this breeding program.