Temporal-Spatial Estimation of Fruit Trees Flowering Dates in West Azerbaijan Province for Reducetion of Climatic Risks

The Agricultural sector, due to its biological conditions, has always been consideredas a risky activity. The unpredictability of most natural hazards has caused challengesfor farmers and gardeners. The present study endeavored to determine the optimumflowering date of pome and stone fruit trees in West Azerbaijan Province based onclimatic conditions. To do so, the minimum and maximum daily temperature data ofmeteorological stations for a statistical period of 20 years was used. The flowering dateof fruit trees was calculated using growing degree days index (GDD), and then theprobability of these dates at different confidence levels were estimated by the SMADAstatistical software. Later, in order to determine the time zones with a same floweringperiod, the estimated dates were determined in ArcGIS10.2 software based on spatialfactors overlap and interpolation functions on the digital elevation model of the region.Based on the required thermal and climatic conditions for the fruit trees of the region,the flowering date of most pome and stone fruit trees occur in May. The completion offlowering period of plum, blueberry, and cherry trees takes place in a shorter interval dueto less thermal need in the region. The flowering of apple, apricots, blueberry, pear, andpeach trees begins in April in the eastern and southern half of the province. Floweringof cherry trees takes place in May with a-month delay compared with other trees. Thecompletion of flowering period for apple, apricots, and cherry trees lasts until earlysummer at high altitudes and cold areas. The earliest flowering occurs in the easternhalf, around Lake Urmia and in Sardasht, in southern area of the province. Climaticconditions and altitude play a significant role in the completion of thermal requirementsof the phenological stage of the fruit trees flowering period. In West Azerbaijan Province,due to an increase in the height, the flowering date delays a month from east to west.Estimating the flowering period is important to take preventive measures in order toreduce the damage during spring in fruit orchards before the occurrence of climatichazards such as cold, frost and hail. The awareness of fruit trees flowering period andinforming others through crisis management programs can be very influential.