Growth and Yield Performance of Several Potato Clones Grown at Three Elevations in Hawaii. I. Plant Morphology

There are few data on the growth and yield of potato (Solanum tuberosum L.) genotypes in the field in tropical and subtropical environments despite interest in such work. Among other things, the data were needed to validate a potato growth model being developed for use in agriculture technology transfer in the tropics. A genotype by environment experiment was conducted on Mr. Haleakala, Maui, HI in 1985 and 1986 at elevations of 91, 282, 640, and 1097 m. The 91 and 1097 m elevations were common in both years. Mean maximum air temperatures during the experimental period for 1985 and 1986 were 29.2 and 30.3 °C at 91 m and 23.1 and 24.0 °C at 1097 m. Mean minimum air temperatures for the same period in 1985 and 1986 were 20.9 and 20.5 °C at 91 m and 14.3 and 15.0 °C at 1097 m. Differences in irradiance across the sites was small. The growth and yield of the standard temperate cultivars Desiree, Katahdin, Kennebec, and Norchip and three heat tolerant clones LT-1, C14-343, and C1-884 were contrasted across the sites. Stem numbers per plant did not differ across elevations but plants were taller, internodes were longer, there were more branches per stem, and the leaf area index was greater for plants grown as the low-elevation sites. Days to tuber initiation decreased significantly as the elevation increased. Numbers of nonmarketable tubers (diam. < 5 cm) were greater at the lowest elevation, whereas a higher percentage of marketable tubers (diam. > 5 cm) was produced at the highest elevation. Katahdin outperformed all cultivars producing relatively high yields of marketable tubers at all elevations. The heat-tolerant clones began tuber initiation earlier than the cultivars, but early tuber formation did not result in higher yields. There was little evidence that the heat-tolerant clones were superior to the temperate cultivars, even at the lowest elevation where temperatures were warmest. This research was supported by the IBSNAT Project, Dep. of Agronomy and Soil Sci., Univ. of Hawaii. Seed tubers were produced as part of BARD Res. Project no. US-427-82.