EFFECTS OF AUTUMN AND WINTER PLANTING AND TEMPERATURE STRESS ON TOTAL YIELD, MARKETABLE YIELD AND YIELD COMPONENTS OF SOME POTATO CULTIVARS

Two separate experiments were conducted to compare the total and marketable yield of eight potato cultivars in winter and autumn planting for selection of adapted cultivars to Khuzestan conditions. The experiments were carried out at Behbahan Agricultural Researeh Station from 1999 to 2001. The first experiment began in January and eight cultivars were compared in a RCBD with four replications. Tubers were planted late in January and harvested in mid May. In the other experiment, the same cultivars were planted early in October and harveted late in February. Frost occurred in November 30 in 1999 and January 25 in 2001. After harvesting, yield of each cultivar was separated into marketable and unmarketable. At the end of experiments total and marketable yield of autumn and winter plantings were analyzed by split plot design in time. According to the obtained results cultivars Binella, Arinda, Sante, Cosmos and Ajax were recommended for winter planting and Sante for autumn planting. Due to the probability of frost occurrence in autumn planting, winter planting is prefered to autumn planting in Khuzestan conditions .