Evaluation and zoning of thermal and phenological conditions of grape cultivation in Hamadan province

Agriculture in the context of climate arrives at a favorable outcome. One of the important goals in agricultural researches is the investigation of effects of atmospheric parameter on various agricultural products. In this research we study the thermal and phenological conditions of grape cultivation in Hamadan province. In this study we analyzed thermal conditions for grape based on minimum and maximum daily temperatures of Meteorological stations in Hamadan province, by use of  thermal potential, normal distribution, optimal deviation, growing degree days (GDD), phenology interphase methods. We also used SMADA software for statistical analyses and by Arc GIS Software to determine the possibility of frost and IDW technique for zoning and presentation of spatial distribution results. The results show that from the southern to the northern of Hamadan province the total heat units is reduced. An examination of the probability of a late spring frost at 95% showed that the date varies from late April in the southern regions of the province to the first decade of May in the northern half of the region. The probable date of late spring frost was seen at the end of April in the southern half (Malayer and Nahavand) areas, which coincides with the phenological stage of germination. The date of these phenological stages complete with a delay of ten days from south to north. The deviation from optimal temperature conditions in each grape phenological stage, in the northern half is more than that of the southern half. According to the research results, early varieties of grapes is suitable for cultivation in the northern half of the region, due to the lower heat potential.