the feasibility of colza autumnal cultivation in hamedan province with focus on agroclimatic conditions by means of gis system

weather and climatic parameters and their impact on farming plants are one of the foremost effective factors on improvement of crop yield. the potential facilities of various regions may be determined with agroclimatic study and exploit maximally from these facilities. in order to evaluate agroclimate of colza cultivation throughout the selected substations at hamedan province in this current investigation, the statistics data related to daily temperatures within a 10- year statistical period were employed. deviation from optimum percentage (dop) technique, growing degree day (active day temperature), and thermal gradient methods have been adapted for computation and agroclimatic analysis. the results of this study indicate that the optimal date for cultivation of autumnal colza in high and cold- weather lands (nahavand and malayer) is the end of october. temperature gradient analysis and dop technique in various heights at the studied region may show that there is one month postponement in deviation from the optimum conditions for optimal cultivation per 100m increase in height of given region. this point is important in terms of date of cultivation and production of commercial product. according to the acquired farming calendar, end of october is the most appropriate time for autumnal cultivation in this area and thus date of harvest will be the end of august.