Studies on the blindness in gladiolus. VII

Abstract

A study was made to know the effect of nutritional contents in corms on the flowering in gladiolus. Corms of the variety Spotlight, which were shown in Table 1, were planted in benches containing sandy soil in the experimental greenhouse at Kagawa University on March 19, 1959, and they were grown with water alone (no fertilizer was added). Number of germinated corms, date of flowering, number of plants died, number of blind stalks, and number of flowered plants were recorded. On July 31, all plants were dug up, and fresh weight of tops, fresh weight of corms, and number of cormels were recorded. Cormels of the same variety which were shown in Table 3 were planted in the same greenhouse on March 20, and they were dug up on June 4, and the fresh weight of the plants was measured. The reasults obtained are summarized as follows: 1. Earlier flowering was observed in the plants to which N 100 ppm and P 25-50 ppm were applied in the previous year, and later flowering in -N plants or the plants to which N 200 ppm alone was applied. 2. Percentage of germination and percentage of flowering were high in the plants to which nitrogen was applied in the previous year, and percentage of plants died and percentage of blind stalks were high in -N plants. Several malformed plants were observed in the plot in which N 200 ppm alone was applied. 3. Number of florets, height of plants, fresh weight of tops, fresh weight of corms, and number of cormels were increased. 4. No significant differences were observed in the number of leaves and fresh weight of cormels. 5. From the results above mentioned it seems that the most superior was the plant to which N 200 ppm and P 50 ppm were applied in the previous year, and the nutritional contents in these corms were 1.99% of nitrogen, 0.31% of phosphorus and 0.57% of potassium in dry matter. The second was the plant to which N 200 ppm and P 25 ppm were applied, and 1.82% of nitrogen, 0. 22%of phosphorus, and 0.49% of potassium were contained in corms.