Potato (Solanum spp.) apical and sprout cutting production and their agronomic potential as transplants

Mother plants could be maintained under lowland conditions for at least 6 months. Cutting production from mother plants could compete with that in a cooler mid-elevation location with an average production of 600 cuttings per 50 mother plants in a period of 140 days. Cutting production was genotype and environment dependent. Sprout cuttings, taken from tubers stored for 9 months in diffused light storage in the lowlands, had good plant survival, vigorous plant growth and large canopy, resulting in acceptable tuber yields from some clones which could compete with yields from tuber seed. Genetic diversity was found within a narrow genetic base, indicating the possibility of breeding potato in the lowlands for adaptation and yield using sprouts. Increasing plant density would have increased tuber yield. Rooted, transplanted, apical cuttings were more susceptible to adverse field growing conditions such as wind, heat and drought, resulting in severe pest damage for some clones infection. For the best five clones with Solanum andigena and S. phureja background, acceptable tuber yields were obtained averaging 12 t/ha on an area basis. There were strong positive linear relationship for canopy duration versus tuber yield and intercepted solar radiaton versus tuber yield. Increasing crop canopy and longevity through selection of adopted genotypes and proper agronomic management may improve tuber yields. There were significant genetic correlation for tuber yields versus canopy duration (r=0.65) and versus tuber weight (r=0.50); between canopy duration and tuber number (r=0.73), and between tuber number and average tuber weight (r=-0.88). Broad sense heritability estimates for tuber number, tuber weight and tuber dry weight (%) were 60%, 85%, and 63%, respectively. Tuber weight, tuber number and canopy duration contributed more than other traits to the tuber yield.