Ornamental Cabbage and Kale Cultivar Comparison Study: Growth Characteristics and Response to Daminozide and Uniconazole Foliar Sprays
Twenty-six ornamental cabbage and kale (Brassica oleracea var. acephala) cultivars were grown in 8-inch (20.8-cm) diameter pots during Fall 1998 to classify their foliage traits and determine their response to the plant growth regulator (PGR) daminozide. Cultivar vigor was classified by height. Foliage characteristics were described and cultivars of ornamental cabbage, notched ornamental kale, and curly ornamental kale were selected for retail or wholesale markets based on the shortest number of days until a significant center color change, the largest center color diameter, and attractive foliage characteristics. Two cultivars treated with 2,500 ppm (mg·L-1) daminozide and eight cultivars treated with 5,000 ppm were significantly smaller in height compared to nontreated plants. Plants were treated 6 weeks after sowing, and the response to the PGRs may have been diminished by the age of the plant. Therefore, to further investigate PGR efficacy, seven outstanding cultivars selected in 1998 were treated with 5,000 ppm daminozide or 5 ppm uniconazole 14 days after potting (4 weeks after sowing) in Fall 1999. Greater control was observed with daminozide at 5,000 ppm in 1999 with a 13% smaller plant height as compared to 9% in 1998, when compared to the nontreated control. For greater height control, PGR applications to ornamental cabbage and kale should be applied 4 weeks after sowing.