Small-sized tuber of sweet potato (Ipomoea batatas Lam.) is more preferred by Korean consumers, because it is convenient to eat with hands, and can easily be steamed or roasted in small pan as a healthy snack for a small family. The present study was aimed to investigate the effect of highdensity plantings and harvesting times on production of smallsized tuber (50~200 g). Four varieties (‘Annobeny’, ‘Daeyumi’, ‘Shinzami’, and ‘Yeonhwangmi’) were planted in 2-row zigzag high-density planting (75×30 cm, A; 75×25 cm, B) and 1-row planting (75×25 cm, control) covered with black vinyl film on May 23th, 2014. Marketable yields and small-sized tuber yields were compared between 120- and 150-day harvesting. Vine length and fresh weight per plant were significantly decreased in 2-row planting A and B plots compared to the control at 120 days after planting. Weight of tuber per plant, mean weight of tuber and number of tuber per plant were significantly decreased in 120-day harvesting of A and B plots than in the control. Marketable yields per 10a were increased by 17% (2.4 ton‧10a -1 ) and 8% (2.6 ton‧10a -1 ) in 120-day harvesting of A and B plots compared to the control (2.4 ton‧10a -1 ), and those were largely increased by 29% (4.0 ton‧10a -1 ) and 26% (3.9 ton‧10a -1 ) in 150-day harvesting than in the control (3.1 ton‧10a -1 ). Proportions of small size tuber (50~200 g) were increased by about 65% in 150-day harvesting of A and B plots compared to the control (55.3%). Small-size tuber yield and marketable yield were highly increased in 150-day harvesting of 2-row zigzag high-density planting A (75×30 cm).

고구마 소형 간식용 생산을 위한 적정 재배기술 확립을 위하여 고구마 삽식기, 재식거리 및 수확시기를 달리하여 소비자의 선호도에 부응한 간식용으로 적합한 소형 고구마 생산을 향상시키고자 시험을 수행하였던 결과를 요약하면 다음과 같다. 1. 소형간식용 고구마생산을 위한 적정 삽식시기는 4월 중순(피복재배)에 삽식거리는 75cm×15~20cm , 6월 중 순(무피복재배) 삽식시 75cm×15cm 가 적합하였다. 2. 고구마 상저수량은 삽식후 수확일수가 길어질수록 증수되었으나, 삽식후 100일 수확이 80일이나 120일 수확보다 소형 간식용으로 적합한 고구마 괴근 비율이 높았다. 3. 삽식시기 및 삽식거리에 따라 상저수량이 차이가 인정되었으며, 4월 15일 조기 비닐피복재배에서 처리간에 변이폭이 적어 안정적이었다. 4. 보통기(5월) 비닐무피복재배보다 조기(4월) 비닐피복 재배가 농가소득이 32~61% 증가되어 유리하였다.