Paclobutrazol for height control of two Lilium L.A. hybrids grown in pots

FRANCESCANGELI, NORA; MARINANGELI, PABLO; CURVETTO, NÉSTOR

SPANISH JOURNAL OF AGRICULTURAL RESEARCH

Spanish National Institute for Agricultural and Food Research and Technology

Lugar: Madrid; Año: 2006 vol. 5 p. 425 - 430

1695-971X

 Height control is often required to obtain bulb plants which are proportional to their pot size and to reduce post-harvest stem elongation. Plant growth regulators afford an effective means of controlling plant height. In this study, paclobutrazol (Pbz) was studied for use in the chemical dwarfing for marketing potted Lilium plants – the hybrids  ‘Ercolano’ and ‘Royal Respect’ – for marketing. Their bulbs were dipped in thegrowth regulator (0, 50, 100, and 150 ppm) for 10 min before planting. Plant height (measured at 7 days intervals), the duration of the different stages of the growth cycle, thec number of flower buds formed, and the number of open and aborted flowers were recorded. The average day and night temperatures were 25 and 13º C, respectively. Increasing Pbz dose progressively reduced the height of the Ercolano hybrid by between 29% (46.2 cm; 50 ppm) and 45% (35.3 cm; 150 ppm) compared to control plants (64.4 cm), however,  neither the duration of flowering nor the number of flowers was modified. The Royal Respect hybrid responded with a marked shortening – by 45% (20.8 cm; 50 ppm) to 59% (28.2 cm; 150 ppm) in comparison with the average control height (51.1 cm), but in this case, both the duration of flowering and the number of open flowers was reduced at the highest concentration. The  feasibility of cultivating these Lilium hybrids for marketing in pots is demonstrated. However, the concentration of paclobutrazol should be adjusted according to the hybrid grown.