Global warming and climatic zoning of apple cultivars with medium chilling requirement on time of bud break in the south of Brazil

Abstract

Apple is a crop of high economic and social importance in the south of Brazil and studies that quantify the impacts of global warming on the future production of this culture are very important. The aim of this study is to determine the impacts of global warming in climatic zoning of apple cultivars with medium chilling requirement on time of bud break, evaluating the expansion or contraction of potential areas for planting for the states of Paraná, Santa Catarina and Rio Grande do Sul, in the south of Brazil. The HadRM3P Climate Model was used as a tool to generate the daily data of precipitation, maximum, average and minimum air temperature for the three scenarios in southern Brazil (current, A2 and B2). The criteria for defining climatic zoning were to: i. the minimum monthly air temperature was less than or equal to 15 °C; ii the average monthly air temperature was less than or equal to 22oC in the months of January, February, March, April, October, November and December; and iii. the chilling hours accumulated from April to September was between 350 and 700. The global warming could reduce, in the long term, the potential areas for production of apple cultivars with medium chilling requirement on time of bud break in the three southern states of Brazil.