Growth and yield of apical stem cuttings of white potato (Solanum tuberosum L.) derived from disease-free G₀ plants

Abstract: Growth and production of apical stem cuttings under various soil-less culture conditions for mass production of potato G₁ seed tubers was investigated. Different cutting lengths, Indole Acetic Acid (IAA) concentration, and age of mother plants from which the cuttings were taken, were evaluated for survival and growth of the cuttings. In separate experiments, successful cuttings were planted at different spacings and fertilizer rates. The highest survival rate was obtained from apical cuttings with three nodes treated with 1 ppm IAA. The best cutting growth was obtained from cuttings derived from 2 to 3 week-old mother plants. Plant height and individual leaf areas were higher at low spacing (10 cm x 10 cm), and a higher dose of NPK fertilizer (40 g/plot). The number of tubers and tuber weight per plant were higher at a spacing of 20 x 20 cm and fertilizer dose of 40 g/plot. Although higher plant density resulted in smaller tuber size, the combination of close spacing and higher doses of fertilizer resulted in the highest yield per unit area. Importantly, stock plants showed no significant decrease in plant yield after cutting. The results indicate that apical cuttings can be used for the mass-propagation of G₀ seed plants to speed up and increase the efficiency of production of G₁ seed tubers.