Focus on Floriculture
The 1981 trials were with 8 cultivars as single stem (3 plants/6 inch pot) or branched (1 pinched plant/6 inch pot) plant grown at 60 or 65 F night temperature. The day temperature was 70-75°F. The cuttings were rooted in Oasis® root cubes. They were potted in a soil/peat/perlite soil mix in plastic pots. Fertilizer applications of 200 ppm N and K (ammonium nitrate, potassium nitrate) and phosphoric acid (water, pH 6.2) were made at each watering. An application of epsom salt (Magnesium sulfate) at 3 lbs/100 gallons of water was made on October 16. Terraclor was applied 1 week after potting and Lesan applied every 4 weeks. Temik was applied every 4-5 weeks. One tablespoon of 14-14-14 Osmocote was applied to each pot on October 2. Cultivars and production schedules are shown in Tables 1 and 2. Height and weeks to flower are shown in Figures 1, 2, 3, and 4. Night temperature had a much greater effect on the height of the branched plants than the single stem plants. Growing at 60 F night temperature greatly increased the time to flowering and significantly reduced bract size. We still recommend a growing temperature of 65 F for poinsettias.
Keywords: Soil/peat/perlite Cultivars Growing temperatur phosphoric acid