Influence of production and storage conditions on subsequent growth and tuber yield of potato (Solanum spp.) in the hot tropics

Abstract

SummaryA series of experiments to quantify the response of diverse potato genotypes to production and storage conditions in hot climates was carried out in 1984–87 at three sites in Peru, two of which were characterized by at least one hot season per year. Yield stability and field performance of seed tubers of six clones produced in situ, and stored in diffused light (DLS) or cold stored (CS), were compared with those of good quality seed tubers produced and stored in cool conditions. The yield potential of tubers produced in hot climates and grown as (i) a double crop per year with short DLS (1–4 months) (ii) a single crop per year with long DLS (c. 8 months) and (iii) a single crop per year with long CS (c. 8 months) was compared with that of seed tubers produced in cool conditions and introduced in successive crops.The first replanting of tubers produced in hot climates resulted in lower yield than that of coolproduced tubers. Yield reductions in clones ranged from 30 to 93% when replanted within 4 months, from 10 to 100% when replanted after 7–10·5 months of DLS and from 0 to 82% after similar periods of CS. Reduced yield was often due to poor plant vigour and crop growth leading to inefficient interception of solar radiation. There was, however, no evidence that the efficiency of utilization of intercepted radiation for tuber dry matter production was influenced by storage treatment. Poor sprout growth at planting reduced yield considerably for late clones in double cropping. Low dry matter content of tubers produced in hot climates did not influence emergence rate, but was related to poor plant vigour in the first replant under warmer conditions. Replanting and storage in hot climates did not enhance the initial reduction of tuber dry matter, which was evident after the first hot season. Tuber yields continued to decline, particularly under single cropping with long DLS.For the clones studied, CS would be a feasible storage method for potato production in hot climates if replanted tubers were used on an annual basis. For double cropping, short dormancy is essential; however, poor plant vigour results in additional yield reductions. Our data indicate that clonal selection for maximum production in hot climates should take into account the proposed or existing production and storage schemes.