Cultivated caladiums (Caladium ×hortulanum Birdsey, Araceae Juss.) are valued for their colorful and variable-shaped leaves (Harbaugh and Tjia, 1985; Wilfret, 1993). Cultivars generally are divided into three groups according to leaf shape and size: fancy-, lance-, and strap-leaved (Wilfret, 1986). Fancy-leaved caladiums produce large round–ovate to triangular leaves with three main veins, two large basal lobes partially to fully joined, and a petiole attached to the back of the leaf blade. Strap-leaved caladiums have linear leaves with one main vein and no obvious basal lobes. Lance-leaved caladiums produce leaves intermediate between fancy and strap types: leaves sagittate to cordate–lanceolate in shape, basal lobes obvious to barely obvious, and petioles attached to the base of the leaves (Deng and Harbaugh, 2006a). The majority of caladium cultivars in commercial production are fancy-leaved (Bell et al., 1998; Deng et al., 2011). However, there has been an increasing demand for lance-leaved cultivars. Florida growers, the primary supplier of caladium tubers used in the world, reported greater than 50% more acres used for producing lance-leaved caladiums in 2008 than in 1998 (Bell et al., 1998; Deng and Alleyne, 2009; Deng et al., 2011).
Plants of lance-leaved cultivars generally are more compact with smaller leaves and shorter petioles than fancy-leaved caladiums. Tubers produced by lance-leaved caladiums tend to be more branched (Deng and Harbaugh, 2008). Therefore, lance-leaved caladiums are adaptable to different container sizes, do not require tuber de-eyeing for pot plant production, and are less expensive and easier to ship from production sites to markets. These characteristics result in significant benefits to growers producing and marketing potted caladium plants (Deng and Harbaugh, 2008). Lance-leaved caladiums may be more resilient to wind damage, drought, sunburn, and shading than fancy-leaved caladiums and may do better than the latter in the landscape when such stresses occur (Deng and Harbaugh, 2008). However, many lance-leaved caladiums often produce small tubers (Wilfret, 1983). Tubers are both the planting stock and the crop for caladium growers. Thus, tuber yield is one of the most important factors determining a cultivar’s economic value for commercial production of caladium tubers. Growers cannot produce cultivars profitably without adequate tuber yield and have to eliminate them from commercial production. Thus, developing new lance-leaved caladium cultivars with adequate tuber yield potential has been a priority breeding objective for the University of Florida (UF) caladium breeding program since its beginning in 1976.
Currently, ‘Florida Sweetheart’ is the most popular lance-leaved commercial cultivar of any color, and ‘Florida Red Ruffles’ is the most popular red lance-leaved commercial cultivar among caladium growers, greenhouse growers, and nurseries (Bell et al., 1998; Deng and Alleyne, 2009; Deng et al., 2011). Both cultivars were introduced by the UF caladium breeding program. Plants of ‘Florida Sweetheart’ are compact and produce wide lance leaves with a rosy color and relatively large tubers (Wilfret, 1991a). ‘Florida Red Ruffles’ has a compact, upright growth habit and excellent sunburn tolerance (Wilfret 1991b).
UF 4412 (Fig. 1) and UF 4424 (Fig. 2) are attractive lance-leaved cultivars with novel, distinct combinations of plant and foliar characteristics. UF 4412 leaves are heart-shaped like ‘Florida Sweetheart’ but have a large red center and numerous netted red veins. UF 4412 plants are taller and produce longer and wider leaves than ‘Florida Sweetheart’ plants. UF 4424 leaves are cordate–lanceolate-like ‘Florida Red Ruffles’ leaves but have a large, glossy, red center and numerous red, thick veins. UF 4412 and UF 4424 were comparable or superior in replicated field, greenhouse, and landscape trials to ‘Florida Red Ruffles’ and ‘Florida Sweetheart’ in tuber yield, pot plant quality, and landscape performance. UF 4412 and UF 4424 are suitable for producing pot plants, and tuber de-eyeing was not required for forcing in small containers. These characteristics should make UF 4412 and UF 4424 economically viable and profitable cultivars for commercial production of caladium tubers. The availability of UF 4412 and UF 4424 can help expand the caladium plant palette for greenhouse growers, nurseries, and gardeners.
Bell, M.L., Wilfret, G.J. & DeVoll, D.A. 1998 Survey of caladium tuber producers for acreage of cultivars grown Proc. Fla. State Hort. Soc. 111 32 34
Deng, Z. & Alleyne, J.C. 2009 2008 survey of caladium growers in Florida. 2009 FSHS (Florida State Horticultural Society) Meeting. Abstract by Section. 27 Aug. 2012. <http://www.fshs.org/Meetings/2009/Abstracts-FSHS_2009.pdf>
Deng, Z. & Harbaugh, B.K. 2006a Independent inheritance of leaf shape and main vein color in caladium J. Amer. Soc. Hort. Sci. 131 53 58
Deng, Z. & Harbaugh, B.K. 2006b ‘Garden White’—A large white fancy-leaved caladium for sunny landscapes and large containers HortScience 41 840 842
Deng, Z. & Harbaugh, B.K. 2008 Caladium breeding: Progress in developing lance-leaved cultivars Proc. Fla. State Hort. Soc. 121 395 398
Deng, Z., Harbaugh, B.K., Schoellhorn, R.K. & Andrew, R.C. 2011 2003 survey of the Florida caladium tuber production industry. Univ. of Fla. /IFAS extension fact sheet, ENH 1007. 27 Aug. 2008. <http://edis.ifas.ufl.edu/EP258>
Geraldson, C.M., Overman, A.J. & Jones, J.P. 1965 Combination of high analysis fertilizers, plastic mulch and fumigation for tomato production on old agricultural land Proc. Soil Crop Sci. Soc. Fla. 25 18 24
Harbaugh, B.K. & Tjia, B.O. 1985 Commercial forcing of caladiums. IFAS, Univ. of Fla. Agr. Ext. Serv. Circ. 621
Rhodes, H.L. 1964 Effect of hot water treatment of seed tubers and soil fumigation for control of root knot on yield of caladiums Plant Disease Reporter 8 568 571
Royal Horticultural Society 1986 RHS colour chart. Royal Hort. Soc., London, UK
SAS Institute 2011 The SAS system for Windows. Release 9.2. SAS Inst., Cary, NC
Wilfret, G.J. 1991a Florida Sweetheart: A rose lance caladium for landscape and containers. Florida Agr. Exp. Stn., Instit. Food Agric. Sci., Univ. Fla., Gainesville, Cir. S-380
Wilfret, G.J. 1993 Caladium, p. 239–247. In: de Hertogh, A. and M. le Nard (eds.). The physiology of flower bulbs, Elsevier, New York, NY