The Ohio State University Learning Gardens Osteospermum Cultivar Trial 2004 Part I GREENHOUSE TRIAL Monica Kmetz-González and Dr. Claudio Pasian OSU Department of Horticulture & Crop Science In 2004, we conducted Osteospermum/African Daisy Trials for the seventh consecutive year in our Departmental greenhouses on the Columbus Campus. We evaluated 26 entries from 4 source companies in the trial period from January through early May. Rooted cuttings were received from participating companies between January 2 - 16. *** See photos of each cultivar entry in Table 2 below *** Cultural Schedule: 1/8 - 1/16/04, Week 0 Rooted cuttings of 20 plants per cultivar were transplanted to 4.5 inch pots. Potting media: MetroMix 360. Greenhouse temperature: 72F day/night. 2/12/04, Week 4 Pinched plants to 5 - 6 nodes. 2/26/04, Week 6 Cold vernalization initiated: 46F day/night 4/8/04, Week 12 Temperature changed back to warm: 65F day/55F night 4/19/04, Weeks 13-14 Cultivars with no vernalization requirement (or minimal vernalization needs) at peak flower. 4/27 - 5/2/04, Weeks 15 -16 Majority of cultivars at peak flower. (Vernalization-requiring cultivars) Fertilization: Greencare 17-5-17 at 200ppm N 3 times/week Disease Problems: --- Pythium root rot was detected on some plants in late January. Plants were drenched with Plant Shield at the maximum rate of 5 oz/100 gal. on January 28 as a preventative measure for further problems. --- Botrytis was detected in mid-April. Treatment with Heritage fungicide @ 6 oz/100 gal. took place on April 23. Height Control: No growth regulators were used in this cultivar evaluation. This provided a good indicator of the natural growth habit of each cultivar. Evaluations Performed: 1). PLANT HEIGHT to top of flowers (Table 1 ) was measured on May 3. Height is presented in both centimeters and inches, and the table is ranked in order of shortest to tallest cultivar. 2). The main CULTIVAR EVALUATION (Table 2 ) was performed by the Trials Leader and Trials Coordinator on April 29. The table is ranked in decreasing order of the Overall rating. Evaluation Criteria: Ratings were based on a 1 - 5 scale: 1 = poor/not acceptable, 2 = fair, 3 = good, 4 = very good, 5 = excellent. Plants were evaluated for the following characteristics: < /FONT > Flower number. Flower quality: Flower aesthetics; color, health and appearance. Vegetative/ Foliage quality: Plant habit, plant vigor, leaf color, health, and appearance of vegetative portion of plants. Overall: Overall rating for all plants in the grouping, taking the above aspects into consideration. 3). The CONSUMER PREFERENCE EVALUATION (Table 3 ) was performed by our Annuals Team of Master Gardeners on April 22 - 27. Plants were given an Overall (1 - 5) rating based on personal preference. 4). FLOWERING BEFORE COLD VERNALIZATION (Table 4 ). We recorded the number of plants with flower buds and open flowers on February 2, just two weeks after transplant. The open flowers were subsequently removed. All plants in the trial were pinched 10 days later on February 12 according to the Cultural Schedule guidelines. The data presented in this table reflects those entries which require minimal or no vernalization treatment. All entries did receive the 6 week prescribed vernalization period, however. Results: The top entries (with an overall ranking of above 4.0) in the Cultivar Evaluation as rated by the Trials Leader and Trials Coordinator at the time of peak flower were: Pinwheel Purple, Symphony Lemon, Symphony Vanilla, and Symphony Orange. Also performing well, and all tied with a ranking of 4.0 were: IN47 , Pinwheel White Eye, Seaside, Exp. V77-9B-3C, Symphony Cream, Iringa, and Margarita Maria. The top 5 entries (with an overall ranking of above 4.0) in the Consumer Evaluation were: Soprano Purple, Nairobi Improved, Symphony Orange, Symphony Lemon, and Iringa . Also performing well with a rating of 4.0 were: Seaside and Exp. V77-9B-3C. Note that both Symphony Lemon and Symphony Orange were top finishers in both Evaluations. Trial Coordinator Comments: **  Each year, we receive an increasing number of entries with little or no cold vernalization requirement. This year, the following entries had plants in flower bud and/or open flower on February 2, just two weeks after transplant and ten days before plants were pinched. At the end of the trial, these entries were all at peak bloom 2 weeks sooner than vernalization-requiring cultivars. Soprano Series (3 cultivars- White, Light Purple, and Purple), Symphony Series (5 cultivars - Cream, Lemon, Orange, Peach, and Vanilla) , and Experimentals IN46 and IN47. **  Since no growth regulators are used in this trial, it is always interesting to observe natural plant heights. Final plant heights almost doubled from the shortest entry, Cape Daisy Nasinga Cream (19 cm, 7.5 in.) to Margarita Rosita (35.5 cm, 14 in.). Entries all finishing off below 20 cm (8 in.), were Cape Daisy Nasinga Cream, Pinwheel White Eye, Pinwheel Purple, and Margarita Maria. Photos: Overview photos of the Greenhouse Trial at peak flower (remember you can access individual cultivar photos from Table 2): Photo 1 , Photo 2, Photo 3. And we thank the following companies for their participation in this year's Greenhouse Trial: • BODGER BOTANICAL: = http://www.michells.com/Bodger/bodger.htm • ECKE = http://www.ecke.com • FIDES North America: = http://www.fidesnorthamerica.com • PROVEN WINNERS: = http://www.provenwinners.com