GROWTH AND FLOWERING OF TWO CLONES OF REINWARDTIA INDICA AT DIFFERENT TEMPERATURE AND DAYLENGTH.

Both clones are short day plants with a critical daylength of about 16 hours for one clone and perhaps 14 hours for the other clone. The critical daylength has only a small variation depending on the temperature.

When the plants were grown at 18°–21°C and short days they flower 42 or 62 days later depending on the clone.

Growth at 24°C gave the highest number of shoots at 8 and 12 hours daylength and also in clone 1 the highest number of shoots with flowers and flowerbuds, while the best in clone 2 was 20–21°C.

The greatest number of flowering sho ots was recorded in plants grown at 8 hour daylength at 15°–24°C in clone 1 and from 12°C to 21°C in clone 2. The number of flowers and flowerbuds on the largest shoot were higher at 8 hours daylength and 21°–24°C in both clones.

When the plants of clone 1 are grown at 8 hours of daylength and at 18°–21°C, they will at flowering have a total of 5.4 shoots, with 5.3 shoots with flower and flowerbuds and 4.2 shoots with flowers. The largest shoot will be 14.9 cm and have 4–5 flowers and flowerbuds. Clone 2 at the same conditions will have in all 30 shoots, 18 shoots with flower and flowerbuds and 3 with flowers. The largest shoot will be 15.2 cm and have 4–5 flowers and flowerbuds.

At 16 hours the vegetative growth was positively correlated to the temperature with clonal differences only at 9°–15°C, and with no temperature dependent internode length. The internode length of clone 1 being 2.5 cm and clone 2 1.5 cm.