Abstract
Three experiments were conducted to clarify the effects of soil moisture on the blindness in gladiolus.
The first experiment Corms of T. E. Wilson variety were planted in wooden poxes with sand in glasshouse, on June 12, 1959. The boxes were grouped into four plots (I, II, III, and IV), and were supplied with water every 1, 3, 6, and 9 days respectively.
The second experiment : Corms of Sequeen variety were planted in a bench with sand in glasshouse on June 6, 1959, and the dry plot was dried up for 5 weeks from June 24 without supplying water, while in the ccntrol, water was supplied almost every day. Samples were taken from each plot every week, and the development of flower bud was observed by binoculor and photographed.
The third experiment : Corms of Sequeen variety were planted in WAGNER'S pots with sand in glasshouse. Water supply was suspended in the “A group for 3, 4, 5, 6, and 7 weeks from June 24, when the first blade emerged. In the “B” group, it was suspended for 2, 3, 4, 5, and 6 weeks from July 15, when the third or fourth blades had emerged, and in the “C” group, for 1, 2, 3, 4, and 5 weeks from July 29, when the fifth or sixth blades had emerged. After the termination of suspension of watering, all plants were supplied with water again almost every day.
1. In the first experiment, 15. 5% of blind plants was recorded in the III plot which was supplied with water on every 6 th day, and 51% in the IV plot which was supplied on every 9 th day, while no blind plant was observed in the I and the II pots. The soil moisture fluctuated from 100. 4% to 22. 2% to water capacity in the III plot, and 101.2% to 36.5% to water capacity in the II plot.
2. In the second experiment, growth of the plants ceased in the dry plot, whereas normal growth was observed in the control plants. Blind plants were not observed in either plot.
3. In the third experiment, it was observed that the resistance to dryness of soil was stronger in early stages of growth than in later stages.
4. From the results obtained, dryness has less serious influence on blind than day length or nutrition when gladiolus is cultured in autumn.
