Peach and nectarine crops, despite their high climatic and market potential, are not yet well exploited in the state of Paraná. The objective of this research was to indicate zones with lower climatic risk for production of these crops in the state of Paraná, Brazil, using climatic risk analysis and agronomic data. Historical data of 32 weather stations of IAPAR were analyzed to estimate and map the risks of late frost and the average totals of chilling hours above 7.2ºC accumulated from May to September. The regions in which the last frost occurs before flowering and with the total chilling hours suitable to the cultivars needs were considered apt. Most of the north, west and the coast of Paraná do not have enough chilling hours. The areas located in the south with altitudes above 800 m are the most suitable. Within the apt areas eight zones were classified according to the chilling requirements of peaches and nectarine varieties and climatic conditions of each region: zone 1 (75 to 150 hf); zone 2 (150 to 200 hf); zone 3 (200 to 250 hf); zone 4 (250 to 300 hf); zone 5 (300 to 350 hf); zone 6 (350 to 400 hf), zone 7 (400 to 450 hf) and zone 8 (> 450 hf). The zones with lower altitude and higher temperatures accumulate less chilling hours from May to September and are indicated for cultivars with lower chilling requirement. The zones with higher altitudes and high chilling accumulation are suitable for varieties with high chilling requirements (> 400 chilling hours). The last frost is likely to occur in the last ten days of August in the colder regions and do not cause damages to suitable varieties of peaches and nectarine. The results obtained in this work support the adoption of policies to foment these crops in the state of Paraná with low risk.
peaches; nectarine; frost; chilling hours; zoning
