고구마 줄기묘의 월동육묘 적정조건

This study was conducted to know the optimum conditions for overwinter culture of sweetpotato stems in PE film house. The stems will be used as transplant shoots in the next year instead of sprouts produced from storage roots. Sweetpotato stems were cut at field on harvest season and planted in PE film house under three different conditions of PE film mulching, tunnel, or mulching plus tunnel in comparison with the non-treatment of PE film on October 10 and November 10. The survival rate of sweetpotato stems, which was evaluated on April 10 after overwinter, was higher in the treatment planted on October 10 than that on November 10, and with PE film treatments, it was higher in tunnel or mulching plus tunnel than that of the non-treatment of PE film. The survival rate of sweetpotato stems to planting densities was 95∼96% in 10 × 2 ㎝ (333 stems/㎡) or in 10 × 4 ㎝ (250 stems/㎡) when compared with 10 × 2 ㎝ (500 stems/㎡). The survival rate under low temperature showed 95% until 20 days at 5 ± 1℃, and 0% within 5 days at 2 ± 1℃. From these results, it was concluded that there were optimum conditions that cutting time is middle October, planting density is 10 × 3 ㎝, and minimum maintenance temperature is 5℃ in growing conditions of sweetpotato stems. Root yield produced by transplanting shoots using the stems was similar to yield by shoots produced from roots, and the survival rate was not different among varieties.