The 2009 ASHS Annual Conference

Three gallon containers of ‘Razzle Dazzle’ crape myrtles [‘Ruby Dazzle’ (pink blooms with bronze-red foliage), ‘Cherry Dazzle’ (cherry red blooms), ‘Snow Dazzle’ (white blooms), ‘Dazzle Me Pink’ (pink blooms) and ‘Raspberry Dazzle’ (raspberry red blooms)], ‘Chickasaw’ crape myrtle and ‘Pocomoke’ crape myrtle were planted in late summer 2006 in full sun landscape trials at Burden Center, a LSU AgCenter agricultural experiment station in Baton Rouge, LA (USDA hardiness zone 8B, AHS heat zone 8). Plants were placed in raised rows of Oliver silt loam soil (normal pH 6.2) approximately five feet apart in a randomized complete block design with each cultivar replicated three times. Supplemental irrigation was provided as needed via a drip system. Plants were fertilized in March 2007 and 2008 with Sta-Green Nursery Special 12-6-6. Pine straw mulch was maintained at a depth of two inches refreshed two times annually. Hand weeding, glyphosate and Amaze pre-emergent granular herbicide were used for weed control. Plants have not been pruned, pinched, or deadhead from the initial planting time through 2008. In addition, fungicides and insecticides were not been applied. Visual quality ratings based on a scale from 1 to 5 (1=dead, below average landscape performance, 3=average landscape performance, 4=above average landscape performance, 5=superior landscape performance) were taken monthly from April – November 2007 and monthly from April – November 2008. Cercospora leaf spot ratings were taken in October 2007 and October 2008 based on a scale from 1 to 6 where 1= no leaf spot, 2=1-10% foliage with leaf spots, 3=11-25 foliage with leaf spots, 4=26-50% foliage with leaf spot, 5=51-75% foliage with leaf spot, and 6=76-100% foliage with leaf spot. Height measurements were taken in October 2007 and October 2008. ‘Pocomoke’ had the tallest overall height. Among the ‘Razzle Dazzle’ group, ‘Snow Dazzle’ and ‘Raspberry Dazzle’ were the tallest plants, followed by ‘Cherry Dazzle’, ‘Dazzle Me Pink’, and ‘Ruby Dazzle’. Leaf spot was not observed on ‘Raspberry Dazzle’. Leaf spot was slight on ‘Ruby Dazzle’ and moderate on ‘Dazzle Me Pink’, ‘Cherry Dazzle’ and ;Snow Dazzle’. Quality ratings were highest for ‘Raspberry Dazzle’, ‘Cherry Dazzle’ and ‘Pocomoke’.