Cutting Production of Poinsettia Cultigens Grown in Central Florida

Abstract

Production of stock plants is essential for the asexual propagation of poinsettia, but variability exists among cultigens in the development of axillary shoots under high day/night temperatures of central Florida. Thirty-eight and 44 cultigens were grown during 1995 and 1996, respectively, and were evaluated for cutting production and subsequent growth of harvested cuttings. Plants were pruned twice prior to cutting harvest, with a projected cutting number of 21 in 1995 and 27 in 1996. Cuttings were graded into three groups based upon stem caliper and overall quality: #1, #2, and cull. Number of #1 cuttings/plant in 1995 ranged from 3.4 to 18.6, represented by `Cortez' and `Ball 838', respectively; a majority of the cultigens produced between 14 and 16 cuttings in the top grade. Number of usable (#1 and #2) cuttings ranged from 4.9 to 30.0, represented by `Cortez' and `Jolly Red', respectively, with a mean of 20.2. Stem caliper of cuttings measured 7 cm from terminal apex ranged from 0.55 cm of `Mikkel 520' to 0.91 cm of `Ball 838'. Cuttings of `Cortez' and `Red Splendor' had poor lateral development. During 1996, number of #1 cuttings ranged from 9.8 (`Picacho') to 22.2 (`Freedom'), with a mean of 16.6. Number of usable cuttings ranged from 14.2 to 31.9, represented by `Cortez' and `Spotlight Dark Red', with a mean of 25.3. Stem caliper ranged from 0.55 cm (`Ball 865') to 0.79 cm (`Supjibi'). Cuttings taken from plants of the `Cortez' series produced few, if any, laterals, while `Marblestar' and `Jolly Red' had up to 50% aborted axillary buds.