Nutrient absorption by genotype in Gloriosa superba L. 'Misato Red' and 'Southern Wind' cultivated on sandy soils in greenhouse

Nutrient absorption by Gloriosa superba L. 'Misato Red' and 'Southern Wind' cultivated in greenhouses on sandy soils in the Misato district of the city of Kochi was investigated. 1. In each cultivar, the total plant dry weight hardly changed for 30 days after planting but thereafter increased sharply to 43-46 g per plant at the time of lifting the new tubers. The dry weight of stems and leaves increased from the flower budding stage, and accounted for 60% of total plant dry biomass at the time of harvesting. That of new tubers accounted for 20% of the total dry weight at the time of harvesting, after which it increased greatly, and accounted for 50% of total plant dry weight at the time of lifting the new tubers. 2. The amounts of the three primary nutrients absorbed per 1 square m were estimated to be 6.2 g N, 1.3 g P2O5, and 9.2 g K2O in 'Misato Red', and 5.9 g N, 1.4 g P2O5, and 10.1 g K2O in 'Southern Wind'. In 'Misato Red', 60-70% of the amount of absorbed macronutrients, including CaO and MgO, were absorbed by the time of harvesting, and for all nutrients except CaO the majority was absorbed by the midpoint of new tuber growth. In 'Southern Wind', 50-70% of macronutrients were absorbed by the time of harvesting, and 90% were absorbed by the midpoint of new tuber growth. 3. The accumulation of some nutrients over the course of the growing season showed a similar trend to that of total plant dry weight. However, accumulation of CaO and Fe in the new tuber was lower than that for the other nutrients. The amount of CaO in the new tuber accounted for 7-13% of the total content at the time of lifting the new tubers. The amount of Fe in the new tuber accounted for 9-10% of the total content at the time of lifting the new tubers. 4. In each cultivar, the P and Zn content in the flowers in the period from pinching to harvesting were higher than those of any other organ, and the floral content accounted for 17-24% of the total content at the time of harvesting. 5. The amount of absorbed Fe was remarkably higher than that of Mn and Zn in both cultivars. 6. In each cultivar, availability of the three primary nutrients was low, i.e. 30-31% for N, 4-5% for P2O5, and 30-34% for K2O.