Chrysanthemum plant named Yellow Tayrona

#The present invention comprises a new and distinct cultivar of Chrysanthemum, botanically known as Dendranthema grandiflora, and referred to by the cultivar name Yellow Tayrona.

#Yellow Tayrona, identified as 0584 (85-249A04), is a product of a mutation induction program. The new cultivar was discovered and selected by Cornelis P. VandenBerg on Nov. 13, 1989 in a controlled environment in Salinas, Calif., as one flowering plant within a flowering block established as rooted cuttings from stock plants which had been exposed as unrooted cuttings to an X-ray source of 2000 rads in Fort Myers, Fla., on May 11, 1989. The irradiated parent cultivar was the cultivar identified as Tayrona, disclosed in U.S. Plant Pat. No. 7,482. Tayrona is described as a decorative spray cut mum with a flat capitulum form; a white ray floret color with a fresh green center of the flower; diameter across face of capitulum of 63 to 73 mm when fully opened; flowering response period of 50 to 57 days after start of short days in Salinas, Calif., and of 64 to 68 days in Bogota, Colombia; plant height of 74 to 86 cm when grown in Salinas with 6 to 11 long days prior to start of short days, and of 97 to 119 cm when grown in Bogota with 14 to 15 long days prior to start of short days; and excellent tolerance to low night temperatures for bud initiation and flower development. The above description of Tayrona has a wider range of measurements than the description of Tayrona in U.S. Plant Pat. No. 7,482. This is based on the continued flowering trials of Tayrona after preparing the plant patent application for Tayrona. Tayrona was commercially introduced in July 1990.

#The irradiation program resulting in Yellow Tayrona had as its primary objective the expansion of color ranges of the parent cultivar Tayrona. The irradiation program comprised irradiating cuttings of the parent cultivar at irradiation levels of 1500, 1750 and 2000 rads. A total of 1198 cuttings harvested from a total of 225 irradiated plants were planted on Sep. 11, 1989, Sep. 4, 1989 and Aug. 21, 1989 for plants irradiated at 1500 rads, 1750 rads and 2000 rads, respectively. Of these, 16 initial selections were made, which selections were then revegetated and reflowered. Four consecutive flowerings resulted in discarding 12 of the original 16 selections on Sept. 4, 1990. Three codes (plants) were reselected prior to discarding on the same date, while four codes were retained as PI (Possible Introduction) status. The four retained codes and the three reselections were tested in Salinas, Calif., and in Bogota, Colombia, ultimately resulting in discarding five of these codes, and the decision to introduce one code 0584 as Yellow Tayrona and one reselected code 0804 as Lemon Tayrona, the latter being disclosed in pending application Ser. No. 07/919760.

#The accompanying photographic drawing is a side view of a single stem cut spray mum of Yellow Tayrona, with the colors being as nearly true as possible with illustrations of this type.

#Of the commercial cultivars known to the inventor, the most similar in comparison to Yellow Tayrona is the parent cultivar Tayrona. All traits of Yellow Tayrona are similar to those of Tayrona, except for the ray floret color. Yellow Tayrona has a yellow ray floret color, while Tayrona has a white ray floret color. Both Yellow Tayrona and Tayrona have a fresh green center of the flower. In several flowering trials in Salinas and Bogota, slight differences in response time and plant height were noted between Tayrona and Yellow Tayrona. However, these differences were not sufficiently consistent to be considered distinguishing differences.

#In the following description color references are made of the Royal Horticultural Society Colour Chart. The color values were determined on plant material grown as a single stem spray cut mum in Salinas, Calif. on Dec. 27, 1991.

#Classification: