This study was conducted to find out the optimum plantlet type and transplanting time on plant growth and mini-tuber formation of potato in aeroponics system. Acclimation plantlet, 1st, 2nd, 3rd, 4th stem cuttings, and non-rooted stem cutting(DOS) were utilized in aeroponics system to find out the optimum plantlet type. And stem cutting were transplanted on Mar. 7, Mar. 14, Mar. 21 and Mar. 28 in spring aeroponics cultivation and on Aug. 31, Sep. 7, Sep. 14 and Sep. 21 in autumn aeroponics cultivation to determine optimum transplanting time.

Among the stem cutting plantlets and acclimation plantlet, the longer stem length was recorded from the 2nd, 3rd stem cuttings in spring cultivation, and similar results were shown in autumn cultivation also. Number of stolons were highest in acclimation plantlet, and showed the tendency to decrease gradually with cutting times. Number of tubers above 3g were similar in acclimation plantlet, 1st and 2nd stem cuttings, and were less in 3rd, 4th stem cuttings than another treatments in spring cultivation, and it was highest in acclimation plantlet and showed the tendency to decrease gradually with cutting times in autumn cultivation. Weight of tubers above 3g was not difference among acclimation plantlet, 1st, 2nd and 3rd stem cuttings in soring cultivation, and no difference among 1st, 2nd and 3rd stem cuttings in autumn cultivation
The stem length of non-rooted stem cutting and days-old stem cuttings showed a vigorous tendency in spring and autumn cultivations, as the stem cutting age is longer. The highest number of 1st stolons were recorded from the non-rooted stem cutting in spring and autumn cultivations, and showed the tendency to increase as the stem cutting age is longer. Number of 2nd stolons were not difference among the non-rooted stem and 25, 35 days-old stem cuttings in spring cultivation, and it was highest in non-rooted stem cutting in autumn cultivation. Number of tubers above 3g were similar in 25, 35 ays-old stem cuttings, and it was less in non-rooted stem cutting and 15 days-old stem cutting than another treatments in spring and autumn cultivations. Weight of tubers above 3g was shown a similar tendency to number of tubers above 3g in spring and autumn cultivation.

The stem length was increased in spring cultivation as delaying the transplanting time. Number of 1st stolons were highest on Mar. 21. Number. of 2nd stolons were higher on Mar. 21 and Mar. 28 than on Mar. 7 and Mar. 14. Numbers of tubers above 3g was highest on Mar. 21. Weight of tubers above 3g was not difference among Mar. 14, Mar. 21 and Mar. 28 and the lowest was recorded on Mar. 7.
The stem length was reduced in autumn cultivation as delaying the transplanting time. Number of 1st stolons were highest on Sep. 21. Number of 2nd stolons were highest. on Sep. 14. Number of tubers above 3g were increased as delaying the transplanting time. The weight of tubers above 3g was not changed with the transplanting time.
There were significant positive correlation among the agronomic traits except stem length and number of 1st stolons in spring cultivation. The stem length showed a significant positive correlation with the weight of tubers in autumn cultivation.