Selection of Cultivars and Growth Response to Planting Distance for Summer Spinach in Alpine Area

This study was carried out to investigate effects of cultivars and to provide the practical production method of spinach (Spinacia oleracea L.) in the summer season for the local farmers of alpine areas. Considering the rate of germination, bolting and resistance to hot temperature, four cultivars ‘Bio’, ‘Kwangchae’, ‘King of Summer’, and ‘Samson’ were selected among the 12 cultivars tested. Seed germination was more than 95% in both cultivars of ‘Platon’ and ‘Samson’. There were not bolted plants from ‘Kwangchae’, ‘King of Summer’, ‘Platon’ and ‘Samson’. Cultivars ‘Bio’, ‘Kwangchae’, and ‘Samson’ showed high resistance to summer climate in alpine areas. The increase of leaf width and number of leaves was typically associated with increasing transplanting distance from 7×7cm to 20×20cm. For example, the fresh weight measured at 30 days after transplanting with 20×20cm distance was two times heavier than the fresh weight at transplanting with 7×7cm distance. However, the 10×10cm transplanting distance was the most effective, considering economic efficiency and spinach quality.