Investigation of phalogenetic stages of raisins grapevine and changes in chilling accumulation that in Iran

One of the crucial factors in the successful production of agricultural products is the climate. Lack of attention to climatic conditions causes the loss of horticultural products. As one of the major crops in Iran, grapes are affected by climate change and anomalies. Due to climate change, assessment of the phenological stages of grapevine and assessment of chill accumulation status is important for the development of this decidous tree and sustainable management of the horticultural sector. In the present study, the phenological stages of the grapevine were determined based on field observations in two consecutive years at Golmakan agrometeorological station. to evaluate the condition of chill accumulation based on dynamic model, data from 55 valid meteorological stations from 1985 to 2013 were evaluated on an hourly and daily time scale. Mann-Kendall nonparametric method was used to investigate the trend of cold accumulation changes.The results showed that grapes require eight phenological stages to complete the developmental period from early April to late November. The highest temperature requirement occurs during the fruit development stage. According to the dynamic modeloccur51 to 91 cold portions. At high latitudes, severe colds and at lower latitudes mild winter have reduced the chill accumulation for the grape tree.Therefore, climate change has emerged as a decrease in the rate of cold accumulation and the inadequate requirement. Therefore, consideration of climatic considerations is important in selecting species and varieties consistent with this decrease in chill units during the period of dormancy of decidous trees.