Agro-climatic zoning in determining zoning of determining the appropriate growth period, planting date and harvesting date of autumn sowing of sugar beet in Kerman province

Water scarcity is of most important limiting factor of sugar beet production in arid and semi-arid world, like Iran. Due to the lack of autumn cultivation of sugar beet in Kerman province, using Agro-climate zoning, concerning various affecting factors on the growth of sugar beets is of the best and lowest-cost method for identification of prone areas for this crop species. In this study, using long-term weather data, occurrence probability of threshold temperatures and developmental stage were calculated. Due to influence of altitude on temperature variables, three-dimensional gradient equations were used for mapping of these factors in geographical information system. The results showed that in the South and east parts of Kerman province, the optimum planting date is the late of October and first days of November. But for the southern of Baft city, first half of October is suitable for planting. For a large parts of the cities of Rafsanjan, Sirjan, Zarand and Bardsir, appropriate planting date was obtained on second half of September. For southern of Kerman province, mid-May is determined of harvest date. Due to temperature limitations, length of growth seasons in these regions are less than central parts. However, these regions have more GDD and appropriate growth days than central parts. It seems that the southern regions of the province, including the cities of Manoujan, Jiroft, Arzuiyeh and Anbarabad with less than 30% probability of vernalisation risk and stemming are quite perfect for sugar beet autumn cultivation.