Potato (Solanum spp.) in an isohyperthermic environment IV. Effects of cutting seed tubers

Abstract Seed tubers are the largest potato-production cost in the warm tropics. Cutting the tubers into small seed-pieces is one way to reduce this expense. Seed-tuber cutting was evaluated in seven experiments with five cultivars (evaluated in one or more experiments) in The Philippines. Cut seed-pieces produced equal or greater yields compared to whole seed tubers at similar seed rates (t ha −1 ). With the cv. Cosima, seed rates from 0.8 to 3.9 t ha −1 (whole or cut) gave yields between 21 and 27 t ha −1 . Lowering seed rates to 0.4 t ha −1 by cutting into small seed-pieces increased yield per unit seed weight planted (highest ratio was 44:1). Cutting resulted in many more stems per unit weight of seed planted, particularly for cultivars with long dormancy (up to 100% increase). Seed-curing for 5 days before planting was essential for cv. P-7 but only slightly advantageous for Cosima. Benomyl or sodium-hypocholorite treatments did not improve suberization or plant growth. Suberization was rapid under the high temperatures ( x = 25° C ) of our study. Seed cutting is feasible in reducing seed rates and for more effective use of large, expensive seed tubers.