تعيين احتمال وقوع تجربي و دوره بازگشت حداقل دما در ماه هاي اسفند فروردين و ارديبهشت در باغ هاي بادام منطقه سامان

Probability of occurrence and return period of minimal temperature in almond orchards at Saman region during March,April and May

AImond is one of the most important horticultural crops in Chahar-Mahal and Bakhtiari. At the present time more than 4000 hectares of this region is under the cultivation of Almond. One of the problems in these orchards is the late chilling which causes 80% decrease yield in many years. Study of agroclimatic conditions, especially daily temperature in March, April and May helps determination of occurrence and return period of late chilling. In this study, absolute temperature and daily frost data were prepared from Shahrekord Synoptic Station form 1975 to 1996. Data were corrected for Saman region using temperature gradient and interpolation equation. Weibull formula was used to calculate probability occurrence and return period at different stages, i.e.. flower initiation, full bloom and fruit setting. According to the results obtained, some recommendations are given in this paper; (a) suitable varieties (i. e., varieties with late blooming) should be used (b) gardeners should be trained, precisely informed and taught prevention and campaign methods against spring chilling.