Caladiums [Caladium ×hortulanum Birdsey, Araceae Juss.] are ornamental aroids widely used as pot and landscape plants for their colorful foliage and ease in growing (Evans et al., 1992; Harbaugh and Tjia, 1985). Tens of millions of caladium tubers are used annually by the worldwide ornamental industries with 70% to 80% forced in containers and 20% to 30% directly planted in the landscape. More than 95% of the tubers used worldwide are produced in central Florida.
Based on leaf shape (fancy or heart-shaped and lance) and predominant leaf color (white, red, pink, and multicolored), commercial caladium cultivars are often separated into eight groups (Bell et al., 1998; Wilfret and Hurner, 1982). Historically, fancy-leaved caladium cultivars have dominated the market. However, during the past two or three decades, the demand for lance-leaved cultivars has increased steadily; growers producing tubers planted greater than 50% more acres of lance-leaved cultivars in 2003 than in 1998 (Bell et al., 1998; Deng et al., 2005).
The compact growth habits of lance-leaved cultivars make them more adaptable to different types and sizes of containers compared with fancy-leaved cultivars, and they are easier and less expensive to ship as potted plants. A popular red lance-leaved caladium cultivar has been ‘Red Frill’, which accounted for ≈70% of the acreage of red lance-leaved cultivars according to the 1998 survey of the Florida caladium growers (Bell et al., 1998). Unfortunately, ‘Red Frill’ and many other lance-leaved cultivars produce small tubers (Wilfret, 1983), making tubers unprofitable to grow and leading to a considerable shortage of tubers for the market demand. Developing new red lance-leaved cultivars with tuber yields exceeding those of ‘Red Frill’ has been an important objective in our caladium breeding program.
Native to the New World's tropical region, caladiums inherently are very susceptible to injury by low temperatures. Chilling injury (CI) can occur to caladium leaves when temperatures are 15.5 °C or lower (Harbaugh, 1990). This sensitivity to low temperatures can lead to increased production costs for heating in greenhouse production of potted caladium plants and restricts geographic and seasonal use of caladiums in the landscape.
In recent years, there has been considerable interest in developing new caladium cultivars resistant to CI. Toward this objective, the University of Florida's Institute of Food and Agricultural Sciences caladium breeding program released ‘Florida Red Ruffles’. This cultivar develops multiple vibrant red leaves and is much improved in tuber yield and resistance to CI compared with other commercial lance-leaved cultivars. It has become the new standard for red lance-leaved caladium cultivars.
‘UF-404’ is an attractive, new red lance-leaved cultivar with a novel coloration pattern (bright red with white blotches scattered between main veins) (Fig. 1). It has been similar or superior to ‘Florida Red Ruffles’ in tuber yield, pot plant quality, and landscape performance. With numerous brightly colored, wide, and lance-shaped leaves that are resistant to sunburn, ‘UF-404’ is well suited for forcing in various size containers, for producing hanging baskets, and for planting in sunny or shady landscape locations. Its tubers are well branched and do not require de-eyeing for forcing in small- or medium-sized pots (11.4 to 15.3 cm) (Fig. 1), and its leaves are more resistant to CI than leaves of ‘Florida Red Ruffles’.
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., Harbaugh, B.K., Schoellhorn, R.K. & Andrew, R.C. 2005 2003 survey of the Florida caladium tuber production industry Univ. of Fla. IFAS extension fact sheet, ENH 1007 16 Feb. 2008 <http://edis.ifas.ufl.edu/EP258>.
Evans, M.R., Wilfret, G.J. & Harbaugh, B.K. 1992 Caladiums as potted and landscape plants Univ. of Fla. IFAS Agr. Ext. Serv. Circ. 1060
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 and Crop Sci. Soc. Fla. 25 18 24
Harbaugh, B.K. 1990 Transit duration × temperature and fertilization of prefinished caladiums affect subsequent growth HortScience 25 554 555
Harbaugh, B.K., Miranda, B.D. & Wilfret, G.J. 2002 Florida Blizzard—A white fancy-leaved caladium for large pots or shady landscapes HortScience 37 844 866
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 Reptr. 8 568 571
Wilfret, G.J. & Hurner G.T. Jr 1982 A survey of caladium cultivars grown in Florida and their characteristics as potted plants Proc. Fla. State Hort. Soc. 95 190 194