Effect of Climate on Spring Phenology and Harvest Dates in 'Fuji' and 'Hongro' Apples in Korea

Spring phenology and harvest dates of two apple cultivars, 'Fuji' and 'Hongro', were observed in 41 orchards across Korea for 4 years between 2011 and 2014. Climate data of each orchard were reconstructed by geostatistical methods on the basis of the network of weather stations and the digital elevation model. From the climate data, the WORLDCLIM bioclimatic variables (Bio 1 to Bio 19) were calculated to find a possibility as predictors. For spring phenology, dates of bud burst, flowering, and full bloom were compared to the climate data set from the previous year to the surveyed year. The monthly temperatures from the last October to April were related to the spring phenology without November in both cultivars. In a case of the bioclimatic variables, the mean temperature of driest quarter (Bio 9) and the mean temperature of coldest quarter (Bio 11) of the previous year were most related. Precipitation could not be found the relation to the spring phenology and harvest dates in both cultivars. Also, harvest dates could not be found any correlation to the climate data set in this study. From these results, we could make future flowering date maps with the scenarios of the RCP (Representative Concentration Pathways) 4.5 and 8.5.