Eur.J.Hortic.Sci. 80 (2) 87-93 | DOI: 10.17660/eJHS.2015/80.2.7|
ISSN 1611-4426 print and 1611-4434 online | © ISHS 2015 | European Journal of Horticultural Science | Original article
Effect of paclobutrazol in potted plants of four cultivars of Dianthus barbatus × chinensis
A. Lenzi, M. Nannicini, P. Mazzeo and A. Baldi
Department of Agrifood Production and Environmental Sciences (DISPAA), University of Florence, Italy
Dianthus barbatus × chinensis is a perennial herb derived from the interspecific cross between Sweet Williams (D. barbatus L.) and China pink (D. chinensis L.). At present cultivated as a cut flower, it could be potential as a flowering potted plant, but height control should be performed. In this study, the possibility to reduce plant height by the use of paclobutrazol (triazole; PBZ) was investigated in four cultivars. In addition, the effect of PBZ on flowering (inflorescence number and size, and flowering time) and on leaf colour was evaluated. Two experiments were carried out in different seasons (corresponding to autumn potting and summer potting, respectively) and PBZ was applied as a substrate drench at different dosages: 0.5, 1, and 2 mg per pot for autumn-potted plants; 0.25, 0.5, and 1 mg per pot for summer-potted plants. Paclobutrazol resulted to be effective in controlling plant height in all the studied cultivars without producing any toxicity symptoms. Neither effect of PBZ on number and size of inflorescences, nor on flowering time was observed. On the contrary, PBZ enhanced leaf colour.
Dianthus spp., flowering pot plant, leaf SPAD, PBZ, plant
growth retardant, plant height control
Significance of this study
What is already known on this subject?
What are the new findings?
It was previously demonstrated that PBZ is effective in controlling plant height and enhancing colour of a large number of floriculture crops. However, different species have their own needs as to way of application (spray or substrate drench) and appropriate dosage.
What is the expected impact on horticulture?
The study showed that PBZ as a substrate drench reduces plant height and enhances foliage colour in potted Dianthus barbatus × chinensis, a species at present cultivated as a cut flower. Appropriate dosage ranges from 0.5 to 1 mg a.i. per pot depending on pot size, cultivar and season.
The ornamental plant market is characterized by being eager for novelties. Therefore, the use of Dianthus barbatus × chinensis as a new flowering pot crop, which is made possible by height control, may represent an opportunity for growers.
- Al-Khassawneh, N.M., Karam, N.S., and Shibli, R.A. (2006). Growth and flowering of black iris (Iris nigricans Dinsm.) following treatment with plant growth regulators. Sci. Hort. 107, 187–193. https://doi.org/10.1016/j.scienta.2005.10.003.
- Bañón, S., Ochoa, J., and González, A. (2001). Manipulation of oleander growth, development and foliage colour by paclobutrazol and ethephon. Gartenbauwissenschaft 66, 123–132.
- Bañón, S., González, A., Cano, E.A., Franco, J.A., and Fernández, J.A. (2002). Growth, development and colour response of potted Dianthus caryophyllus cv. Mondriaan to paclobutrazol treatment. Sci. Hort. 94, 371–377. https://doi.org/10.1016/S0304-4238(02)00005-5.
- Bañón, S., Ochoa, J., Fernández, J.A., González, A., Sánchez, J.J.M., and Franco, J.A. (2003). Plant growth retardants for introduction of native Reichardia tingitana. Acta Hort. 598, 271–277. https://doi.org/10.17660/ActaHortic.2003.598.41.
- Barrett, J.E., Bartuska, C.A., and Nell, T.A. (1994). Comparison of paclobutrazol drench and spike applications for height control of potted floriculture crops. HortSci. 29, 180–182.
- Currey, C.J., and Lopez, R.G. (2010). Paclobutrazol pre-plant bulb dips effectively control height of ‘Nellie White’ Easter Lily. HortTechnol. 20, 357–360.
- Faust, J.E., Korczynski, P.C., and Klein, R. (2001). Effects of paclobutrazol drench application dates on poinsettia height and flowering. HortTechnol. 11, 557–560.
- Foley, T., and Keever, G.K. (1991). Growth regulators and pruning alter growth and axillary shoot development of Dianthus. J. Environ. Hort. 9, 191–195.
- Gent, M.P.N., and McAvoy, R.J. (2000). Plant growth retardants in ornamental horticulture: A critical appraisal. In Plant Growth Regulators in Agriculture and Horticulture: Their Role and Commercial Uses, M.S. Basra, ed. (New York: Haworth Press), pp. 89–145.
- Kim, S.H., De Hertogh, A.A., and Nelson, P.V. (1999). Effects of plant growth regulators applied as sprays or media drenches on forcing Dutch-grown bleeding heart as a flowering potted plant. Hort-Technol. 9, 629–633.
- Larcher, F., Berruti, A., Gullino, P., and Scariot, V. (2011). Reducing peat and growth regulator input in camellia pot cultivation. Hortic. Sci. (Prague) 38, 35–42.
- Mansuroglu, S., Karaguzel, O., Ortacesme, V., and Sayan, M.S. (2009). Effect of paclobutrazol on flowering, leaf and flower colour of Consolida orientalis. Pak. J. Bot. 41, 2323–2332.
- Meijón, M., Rodrìguez, R., Cañal, M.J., and Feito, I. (2009). Improvement of compactness and floral quality in azalea by means of application of plant growth regulators. Sci. Hort. 119, 169–176. https://doi.org/10.1016/j.scienta.2008.07.023.
- Mishra, D.K., Mishra, H.R., and Yadava, L.P. (2005). Influence of paclobutrazol on early flowering and aesthetic value of China aster (Callistephus chinensis L. Nees). J. Appl. Hort. 7, 34–37.
- Nasr, M.N. (1995). Effect of method of application and concentration of paclobutrazol on Pelargonium zonale (L.) as a pot plant. Alexandria J. Agric. Res. 40, 261–279.
- Newton, L.A., and Runkle, E.S. (2010). Effects of paclobutrazol sprays on inflorescences of three potted moth orchid clones. HortSci. 20, 892–895.
- Pan, R.C., and Luo, Y.X. (1994). Effect of PP333 on growth, development and leaf structure of Cymbidium sinense. Acta Hort. Sinica 21, 269–272.
- Ranney, T.G., Bir, R.E., Conner, J.L., and Whitman, II, E.P. (1994). Use of paclobutrazol to regulate shoot growth and flower development of ‘Roseum Elegans’ Rhododendron. J. Environment Hort. 12, 174–178.
- Thompson, D.I., Anderson, N.O., and Van Staden, J. (2005). Watsonias as container plants: using paclobutrazol for flowering and height control. S. Afr. J. Bot. 73, 426–431.
- Wahyuni, S., Krisantini, S., and Johnston, M.E. (2011). Plant growth regulators and flowering of Brunonia and Calandrinia sp. Sci. Hort. 128, 141–145. https://doi.org/10.1016/j.scienta.2011.01.004.
- Whipker, B.E. (2013). Growth regulators for floricultural crops in greenhouses. In 2013 Plant Growth Regulator Guide, GrowerTalks Magazine, C. Beytes, ed. (West Chicago, IL: Ball Publishing), pp. 8–37.
- Whipker, B.E., and Latimer, J.G. (2013). Wide assortment of available PGRs. In 2013 Plant Growth Regulator Guide, GrowerTalks Magazine, C. Beytes, ed. (West Chicago, IL: Ball Publishing), pp.
- Yewale, A.K., Belorkar, P.V., Jayeeta, B., Chanekar, M.A., and Chimurkar, B.S. (1998). Effect of paclobutrazol on thickness of stem, flower diameter, fresh weight and dry weight of aerial portion of chrysanthemum. J. Soil Crops 8, 73–75.
Received: 10 July 2014 | Revised: 14 October 2014 | Accepted: 18 November 2014 | Published: 22 April 2015 | Available online: 22 April 2015