Field experiments were conducted at Central Potato Research Institute, Simla (H. P.) during 1976 and 1977 on potato (cv. Kufri Jyoti), to find the optimum intra-row spacings for planting different sizes of seed tubers. Optimum intra-row spacings for 20, 40, 60, 80 and 100 g seed sizes were 10, 20, 30, 40 and 40 cm, respectively, when inter-row spacing was 60 cm. Increasing the intra-row spacing beyond 40 cm for planting of even 100 g tubers significantly reduced the yield. Large-sized seed tubers emerged faster and produced significantly higher number of main stems and tubers per plant. The number of tubers per plant was significantly correlated (r = +0.86) with the number of main stems per plant. The number of main stems/m2 was significantly correlated (r= +0.83) with the tuber yield and 21–23 main stems/m2 were the optimum. Proportion of large sized tubers produced was more at wider spacings and that of medium size tubers at closer spacings.
