Study on the agro-meteorological indices at different phenological stages and yield ‎of new potato cultivars in winter planting

In order to study agro-meteorological indices at different phenological stages and yield of new potato cultivars in winter planting in Behbahan Agriculture Research Station an experiment was conducted in randomized complete block design including 11 cultivars in three replications. The results showed that at tuber bulking stage the highest growth degree day and helio thermal unit (respectively 1003.97 °C day and 7301.90°C day hr-1) belonged to Sante cultivar. The maximum photo thermal index in all studied cultivars belonged to tuber bulking stage. Evaluation the correlation coefficient between characters showed that, yield exhibited significant positive correlation with growth degree day (r=0.387) at tuber bulking stage. The highest plant height (67.90 cm) and minimum days to canopy closure (71.33 days) belonged to Savalan cultivar. The highest yield (34.28 t ha-1), heat use efficiency (18.95 kg ha-1°C day-1) and helio thermal use efficiency (2.06 kg ha-1°C day hr-1) were found in Savalan cultivar. According to result Savalan, Ottawa, Jelly, Georgina and Bunba cultivars are recommended for winter potato planting in Behbahan.