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Evaluation of Marigold Cultivars as Bedding Plants – Fall 2000
Richard O. Kelly[1], Brent K. Harbaugh[2] and Rick Schoellhorn[3]
Summary. We evaluated 41 cultivars of African marigold (Tagetes erecta), and French marigold (Tagetes patula) in replicated class tests at the University of Florida Gulf Coast Research and Education Center at Bradenton, Fla. [lat. 27.4 N, long. 82.5 W; AHS Heat Zone 10; USDA (American Horticultural Society, 1999); USDA Cold Hardiness Zone 9b (U. S. National Arboretum, 1990] in the fall of 2000. In this report we provided objective plant measurements of vegetative and flower characteristics (Table 1) as well as 3 subjective ratings (Nov. 1, 16 and Dec. 6) that permit readers to evaluate foliage and flower characteristics (Table 2) at different times during the season, and to evaluate performance over time. Subjective ratings were on a scale from 1 to 7 with the highest rating of 7 for excellent. In general, cultivars with vegetative and floral ratings > 5 were considered outstanding, 4 – 4.9 as good performers, and < 3.9 as fair to poor. Cultivars were grouped into classes based on species, plant height, flower type, and flower color. Outstanding cultivars (overall rating > 5) in their class were: ‘Bonanza Gold’ and ‘Golden Boy’ (French dwarf – double gold class); ‘Bonanza Orange’, ‘Bounty Orange’, ‘Orange Boy’, ‘Orange Jacket’, and ‘Orange Gate’ (French dwarf – double orange class); ‘Bounty Yellow’ and ‘Yellow Boy’ (French dwarf – double yellow class); ‘Bonanza Bolero’ (French dwarf – double gold/red class); ‘Harmony Boy’ (French dwarf – double orange/red class); ‘Little Devil Fire’ (French dwarf – double red/yellow class); ‘Spry Boy’ (French dwarf – double yellow/red class); ‘Granada’ (French dwarf – single gold/red class); ‘Durango Gold’ (French – double gold class); ‘Durango Bee’, ‘Durango Red’, and ‘Honeycomb’ (French – double red/yellow class).
This research was supported by the Florida Agricultural Expt. Station, and donations of money, seeds and fertilizer from the following companies: Ball Seed Company; Ernst Benary Seed Growers, Ltd., Bodger Seeds, Ltd.; Floranova Ltd.; Florikan E.S.A. Corp.; Goldsmith Seeds; Grimes Seeds & Plants; PanAmerican Seed; and Syngenta Seeds Inc. We thank Joyce Jones, Nancy West, and Gail Bowman for their excellent technical support.
The United States wholesale value of floricultural crops was $4.6 billion in 2000, estimated from growers with sales ≥ $10,000. (United States Department of Agriculture, 2001). Bedding and garden plants comprise 50% of the floriculture value at $2.12 billion. Florida ($107.4 million) ranks fifth behind California, Michigan, Texas and Ohio, who together generate 42% of the bedding/garden plant wholesale value. Hybrid marigolds are ranked fourth and eleventh in the United States for wholesale value in flat and pot culture, respectively (United States Department of Agriculture, 1998). Florida was number one (growers with sales > $100, 000) in the United States for the number of potted marigolds produced, and their wholesale value was $1.2 million in 1999-2000 (United States Department of Agriculture, 2001).
Most of the bedding plant variety trials currently conducted in the United States are performed without multiple experimental units replicated in an appropriate experimental design that allows statistical analysis, thus these variety trials provide results that are of questionable scientific merit. This study was conducted to evaluate marigold performance in a seasonal replicated trial in order to provide evaluations that may be used by growers, landscapers, consumers and seed companies as well as the scientific community.
Seeds of 41 cultivars of African and French marigolds were sown on 16 Aug. 2000 into a soil mix containing peat and vermiculite (1:1, volumetric) prepared and amended with dolomite 11.3 lbs./yd3 (6.7 kg/m3), superphosphate 5.6 lbs./yd3 (3.3 kg/m3) and hydrated lime 2.8 lbs./yd3 (1.7 kg/m3) and used for seed germination at 72 to 75 °F (22 to 24 °C) in a growth room with a photosynthetic photon flux (PPF) of 30 μmol·m-2·s-1 for 12 h from cool-white fluorescent lamps. Immediately after germination, seedlings were transplanted into Toddâ planter flats [model 128: 1.5 inches x 1.5 inches x 2.5 inches (3.8 cm x 3.8 cm x 6.4 cm) cells; Speedling Incorporated, P. O. Box 7220, Sun City, Florida] and placed into a screen sided, fiberglass covered greenhouse. Seedlings were fertilized weekly with a 20N-16.6P-8.7K water soluble fertilizer (20-20-20 Ca-Mg Excel; Scotts Co., Maryville, Ohio) solution containing N at 500 mg·L-1. Due to inclement weather delaying bed preparation, growth regulation in the transplant flat was required using 1500 mg·L-1 Cycocel + 2500 mg·L-1 B-nine on 15 and 22 Sept.
On 25 Sept., plugs were transplanted into raised ground beds with six plants per plot spaced 12 inches (30.5 cm) apart in a staggered layout. Beds were 32 inches wide x 8 inches high (81.3 cm x 20.3 cm). Nutricote® 13N-5.7P-10.8 K fertilizer (13-13-13 100-d slow release type; Florikan, Sarasota, Florida) was applied by hand to each plant on the soil surface approximately an inch from the plant stem under the plastic mulch at 261 lb /row acre (293 kg·ha-1) of nitrogen. Beds were fumigated at least 14 days before planting with a mixture of 66% methyl bromide and 33% chloropicrin at 392 kg·ha-1 (350 lb/acre) and covered with white-on-black polyethylene film. Subsurface seepage irrigation water was supplied from lateral ditches spaced 12.8 m (42 ft) apart (Howe and Waters, 1997).
Integrated pest management was employed to determine when pesticide applications were needed to control arthropod pests and plant pathogens. Temperature @ 2 ft (61.0 cm) during the remainder of the experiment ranged from a low of 5.2 °C (41 °F) to a high of 34.3 °C (94 °F) with a total rainfall of 4.5 cm (1.7 inches).
On 3 Nov., three plants per plot were selected from the center and edge of each plot, and the plant height (from the stem base to the inflorescence tip) and plant width were recorded for each plot. Plants in each plot were selected from the same positions in that plot. Subjective ratings were made for each cultivar on Nov. 1, 16 and Dec. 6. Each cultivar was rated on a 1 to 7 scale with the highest rating of 7 for excellent. Plant characteristics that merited a 7 were: (1) all plants in a plot had full and uniform foliage; (2) foliage and flowers were free of pest symptoms; (3) plants were free of abnormalities or weaknesses such as lodging; and (4) flowers were numerous and uniformly distributed over the plant.
In order to provide meaningful performance comparisons, cultivars were divided into the following classes: species (African and French), height [dwarf <10 inches (25.4 cm); > 10 inches), flower form (double if crested or anemone, or single), and flower color (gold, orange, red, yellow, and bicolored). Bicolored classes were represented as x/y, with x = primary color and y = secondary or less predominant color.
Each class was analyzed as a separate experiment. A randomized complete block experimental design was used with three blocks each containing six plants that represented the experimental unit. All data were analyzed by analysis of variance (ANOVA) methods, and means of dependent variables significant at the 0.05 level of probability were separated using Duncan’s multiple range test (PROC ANOVA, SAS Institute, Cary, North Carolina).
African –orange class. ‘Marvel Orange’ (38 cm; 15 inches) was similar to ‘Royal Orange’ (36 cm; 14.2 inches) in plant height, but was significantly taller than ‘Orange Lady’ (33 cm; 13 inches). Plant widths ranged from 31 cm (12.2 inches) for ‘Orange Lady’ to 34 cm (13.4 inches) for ‘Royal Orange’. Flower diameter was significantly larger for ‘Royal Orange’ (8.1 cm; 3.2 inches) than ‘Orange Lady’ (6.5 cm; 2.2 inches) and ‘Marvel Orange’ (6.7 cm; 2.6 inches). First open flower ranged from 54 to 56 d. Flower divergence ranged from 3.8 d for ‘Orange Lady’ to 8.3 d for ‘Marvel Orange. Foliage ratings were equally superior (5.8) for all cultivars in the class on the 1 Nov., but were dramatically lower (3.0 to 3.5) 6 Dec., averaging 4.3 for ‘Orange Lady’ and ‘Marvel Lady’ and 4.6 for ‘Royal Orange’. Flower ratings followed the same monthly pattern, however, by 6 Dec., the average flower rating for ‘Royal Orange’ (4.3) was significantly better than ‘Orange Lady’ (2.9) and ‘Marvel Orange’ (3.1), owing to superior performance by ‘Royal Orange on 16 Nov. Overall average ratings by ‘Royal Orange’ were significantly higher for ‘Royal Orange’ (4.4) than ‘Orange Lady’ for (3.6) and ‘Marvel Orange’ (3.7).
African – white class. ‘Sweet Cream’ had a plant height of 34 cm (13.4 inches), a plant diameter of 37 cm (14.6 inches), and a flower diameter of 6.0 cm (2.4 inches). It took 54 d to flower, with a flower divergence of 6.5 d. Foliage and flower performance was 5.0 and 4.3, respectively on 1 Nov., but steadily declined, yielding an average rating of 3.6 for foliage and 2.4 for flower, rendering a low overall average of 3.9.
African – yellow class. Plant height ranged from 34 cm (10.2 inches) for ‘Marvel Yellow’ to 38 cm (11.0 inches) for ‘Royal Lady’ and ‘First Lady’ (39 cm; 15.4 inches). Plant widths were similar in the class, and ranged from 32 cm (12.6 inches) for ‘First Lady’ to 36 cm (14.2 inches) for ‘Royal Lady’. Flower diameter was significantly greator for ‘Royal Lady’ (7.7 cm; 3.0 inches) than all other cultivars, ‘ ‘Primrose Lady’ was smallest at 7.0 cm (2.8 inches). ‘Marvel Yellow’ (58 d) and ‘Royal Lady’ (59 d) were significantly shorter than ‘First Lady’ (62 d) and ‘Primrose Lady’ (61 d). Flower divergence was similar at 2 d for ‘Marvel Yellow’ and 3.0 d for ‘First Lady’. Though overall ratings for this class were similar, ranging from 3.3 for ‘Marvel Yellow’ to 3.9 for ‘First Lady’ and ‘Primrose Lady’, and the average foliage ratings, ranging from 2.2 for ‘Marvel Yellow’ to 4.3 for ‘Primrose Lady’, the flower ratings were higher for ‘Royal Yellow’ (4.8) (4.3) , that for ‘First Lady (3.9) and ‘Primrose Lady’ (3.5).
French dwarf – double gold class. Plant height ranged from 27 cm (10.6 inches) for ‘Bonanza Gold’ to 32 cm (12.6 inches) for ‘Golden Boy’, while plant widths were 34 cm for both of these cultivars. ‘Bonanza Gold’ (5.1 cm; 2 inches) had significantly larger blooms than ‘Golden Boy’ (1.5 inches). First flower ranged from 31 d for ‘Bonanza Gold’ to 37 d for ‘Golden Boy’, while divergence ranged from 19 d for ‘Bonanza Gold’ to 24 d for ‘Golden Boy’. Average foliage ratings ranged from 4.7 for ‘Bonanza Gold’ to 4.9 for ‘Golden Boy’, while both cultivars had equally high average flower ratings (5.6). Both cultivars had similarly superior overall ratings.
French dwarf – double orange class. Plant height from 21 cm (8.3 inches) for ‘Bounty Orange’ to 32 cm (12.6 inches) ‘Bonanza Orange’. ;, Plant widths ranged from 31 cm (12.2 inches) to ‘Bonanza Orange’ 37 cm (14.6 inches) and ‘Bounty Orange’. ‘Bonanza Orange’ had significantly larger flowers (6.1 cm; 2.4 inches), and ‘Orange Boy’ had significantly smaller flowers (3.8 cm; 1.5 inches) than all other cultivars in the class. Days to first open flower ranged from 28 d for ‘Bounty Orange’ and ‘Orange Gate’ to 54 d for ‘Orange Boy’, while divergence ranged from 6 d for ‘Orange Boy’ to 41 d for ‘Bounty Orange’. Superior foliage and flower performance yielded a significantly higher overall rating of 6.4 for ‘Orange Boy’ than all other cultivars. All cultivars had good to superior ratings, with the lowest being 5.0 for ‘Orange Gate’.
French dwarf – double yellow class. Plant height ranged from 26 cm (10.2 inches) for ‘Bounty Yellow’, ‘Boy Yellow’ and ‘Yellow Gate’ to 30 cm (11.8 inches) for ‘Yellow Jacket’ . Flower diameters for ‘Bonanza Yellow’ (5.4 cm; 2.1 inches) and ‘Yellow Gate’ (5.5 cm; 2.2 inches) were significantly larger than all other cultivars in the class, with ‘Yellow Boy’ (4.0 cm; 1.6 inches) and Yellow Jacket (4.3 cm; 1.7 inches) having the smallest flowers. First flowers opened within 17 d for ‘Yellow Gate’ to 35 d for ‘Yellow Boy’ and ‘Yellow Jacket’. Divergence ranged from 19 d for ‘Bounty Yellow’ to 49 d for ‘Yellow Gate’. Overall superior performance averages for ‘Bounty Yellow’ (5.4) and ‘Yellow Boy’ (5.7), significantly higher than all others in the class, resulted from good to superior foliage (averaged 5.6) and flower ratings (averaged 5.6-5.8) throughout the season.
French dwarf – double gold/red class. Plant heights for ‘Bonanza Bolero’ (23 cm; 9.1 inches) and ‘Bounty Spry’ (21 cm; 8.3 inches) were similar. ‘Bonanza Bolero’ (6.0 cm; 2.4 inches) had significantly larger flowers than ‘Bounty Spry’ (4.2 cm; 1.7 inches). Flowering began within 26 d for ‘Bonanza Bolero’ and 32 d for ‘Bounty Spry’, while divergence was only 14 d for ‘Bounty Spry’, but 16 d for ‘Bonanza Bolero’. There was no significant difference in all subjective ratings for both cultivars, earning good to superior ratings all season.
French dwarf – double orange/red class. ‘Harmony Boy’, the only entry in the class, had a plant height of 27 cm (10.6 inches), plant width of 34 cm (13.4 inches) and flower diameter of 3.9 cm (1.5 inches). The first flower appeared at 50 d, and the flower divergence was 8 d. All subjective ratings were superior, yielding an overall performance rating of 5.7.
French dwarf – double red/gold class. Plant height for ‘Golden Gate’, the only entry for this class, was 32 cm (12.6 inches). Plant width was 37 cm (14.6 inches), and flower diameter measured 34 cm (13.4 inches). Flowering began at 35 d, and divergence was 16 d. The rating for overall performance (4.5) was good.
French dwarf – double red/yellow class. Plant heights for ‘Bonanza Bee’ (25 cm; 8.9 inches) and ‘Bonanza Flame’ (26 cm; 10.2 inches) were significantly greater than ‘Little Devil Fire’ (17 cm; 6.7 inches). Plant widths were also similar for ‘Bonanza Bee’ (33 cm; 13 inches) and ‘Bonanza Flame’ (32 cm; 12.6 inches), and significantly wider than ‘Little Devil Fire’ (26 cm; 10.2 inches). Flower diameters were also similarly greater for ‘Bonanza Bee’ (5.3 cm; 2.1 inches) and ‘Bonanza Flame’ (5.1 cm; 2.0 inches) than ‘Little Devil Fire’ (4.2 cm; 1.7 inches). First flower was 31 d for ‘Bonanza Flame’ and ‘Little Devil Fire’, and 30 d for ‘Bonanza Bee’. Flower divergence ranged from 12-13 d, respectively, for ‘Bonanza Bee’ and ‘Bonanza Flame’ to 24 d for ‘Little Devil Fire’. Overall performance for ‘Little Devil Fire’ (5.5) was significantly better than ‘Bonanza Bee’ and ‘Bonanza Flame’ (4.7). As a result of its superior overall rating ‘Little Devil Fire’ replaces ‘Bonanza Flame’ as best of class for 2002.
French dwarf – double yellow/red class. The plant height for the only entry in this class, ‘Spry Boy’, was 28 cm (11.0 inches). The plant width was 35 cm (13.8 inches), and the flower diameter was 3.9 cm (1.5 inches). The first flower opened at 51 d, while flower divergence was 10 d. Foliage and flower ratings were superior all season with an overall rating of 6.0.
French dwarf – single gold/red class. ‘Granada’ was the only cultivar in this class, and had a plant height of 26 cm (10.2 inches), a plant width of 33 cm (13.0 inches), and a flower diameter of 4.6 cm (1.8 inches). The first flower opened in 51 d, and divergence spanned 13 d. Average foliage (5.4) and flower (5.6) ratings led to an overall performance rating of 5.5.
French dwarf – single red/orange class. ‘Red Marietta’ was the only cultivar trialed, having a plant height of 31 cm (12.2 inches), a plant width of 33 cm (13 inches), and flower diameter of 4.5 cm (1.7 inches). First flower occurred in 51 d, and divergence was 16 d. The ratings on 1 Nov. for foliage (5.0) and flower performance were superior to good, but a steady decline in ratings during the season resulted in a poor overall performance rating of 3.6.
French – double gold class. ‘Durango Gold’ had a plant height of 33 cm (13.0 inches), a plant width of 37 cm (14.6 inches), and a flower diameter of 6.5 cm (2.6 inches). First flower opened at 52 d, and flower divergence was 10 d. Average ratings for foliage (5.0) and flowers (5.2) yielded an overall rating of 5.1 for this superior performer.
French – double orange class. ‘Durango Orange’ was the only cultivar trialed in this class, with a plant height measuring 29 cm (11.4 inches), and a plant width of 35 cm (13.8 inches). Flower diameter was 6.1 cm (2.4 inches). First flower opened at 33 d, and flower divergence was 22 d. Foliage ratings (4.8) were good, but fell to poor (3.0) the rest of the season. Flower ratings were highest on 16 Nov. (5.3), and lowest on 6 Dec. (4.5).
French – double yellow class. Plant height ranged from 27 cm (10.6 inches) for ‘Durango Yellow’ to 35 cm (13.8 inches) for ‘Durango light Yellow’. Plant widths were similar at 34 cm (13.4 inches) for ‘Durango Yellow’ and 38 cm (15.0 inches) for ‘Durango light Yellow’. Flower diameters were similar at 5.4 cm (inches) for ‘Durango Yellow’ and 5.9 for ‘Durango light Yellow’. First open flower ranged from 23 d for ‘Durango light Yellow’ to 31 d for ‘Durango Yellow’. Flower divergence was 21 d for ‘Durango Yellow’ and 38 d for ‘Durango Light Yellow’. Average foliage ratings ranged from 4.1 for ‘Durango Yellow’ to 4.2 for ‘Durango Light Yellow’, and average flower ratings ranged from 4.9 for ‘Durango Light Yellow’ to 5.0 for ‘Durango Yellow’, yielding similar overall ratings ranging from 4.5 for ‘Durango Light Yellow’ to 4.6 for ‘Durango Yellow’.
French dwarf – double red/yellow class. Plant height ranged from 24 cm (9.4 inches) for ‘Durango Red’ to a significantly taller 32 cm (12.6 inches) for ‘Honeycomb’. Plant width ranged from 30 cm (11.8 inches) for ‘Durango Red’ to 34 cm (13.4 inches) for ‘Honeycomb’. Flower diameter ranged from 5.0 cm (2.0 inches) for ‘Honeycomb’ to 5.9 cm (2.3 inches) for ‘Durango Flame’. First open flower ranged from 24 d for ‘Durango Red’ to 61 d for ‘Honeycomb’. ‘Honeycomb’ outperformed all other cultivars in the class with significantly higher average foliage (6.6), flower (6.3) and overall ratings (6.4). Performance was good to superior for ‘Durango Bee’, ‘Durango Flame’, and ‘Durango Red’.
While early or late season performance, a particular plant height, or shade of the same color may be a selection criteria outweighing seasonal performance, the combined foliage and flower ratings represent an overall view of performance for each cultivar in its class over the entire season. We consider cultivars with a combined rating average > 5 as outstanding, 4 to 4.9 as good performers, and < 3.9 as fair to poor. This is a summary of overall performance (combined foliage and flower ratings) by class for those classes trialed this season: African – gold class: all cultivars had fair to low ratings, the highest being ‘Marvel Gold’. African – white class: ‘Sweet Cream’ performed poorly. African – yellow class: though all cultivars similarly ranked in overall performance ‘Royal Yellow’ and ‘Marvel Yellow’ had good average flowering ratings. French dwarf – double gold class: ‘Bonanza Gold’ and ‘Golden Boy’, had similarly outstanding performance. French dwarf – double orange class: all cultivars in this class had outstanding performance, with ‘Orange Boy’ significantly better that the others. French dwarf – double yellow class: all cultivars had good ratings, but ‘Bounty Yellow’ and ‘Yellow Boy’ were outstanding. French dwarf – double gold/red class: ‘Bonanza Bolero’ and ‘Bounty Spry’ were not significantly different, with very good to outstanding performance. French dwarf – double orange/red class: ‘Harmony Boy’ was outstanding. French dwarf – double red/gold class: ‘Golden Gate’ had good overall ratings. French dwarf – double red/yellow class: ‘Little Devil Fire’ had outstanding performance, while the other members were all good. French dwarf – double yellow/red class: ‘Spry Boy’ was outstanding during the entire evaluation period. French dwarf – double gold/red class: ‘Granada’ was outstanding throughout the trials. French dwarf – single red/orange class: ‘Red Marietta’ had fair to poor overall ratings. French double – gold class: ‘Durango Gold’ had outstanding overall performance, doing well all season. French double – orange class: ‘Durango Orange’ had good overall ratings, with some poor foliage ratings lowering performance. French double – yellow class: ‘Durango Light Yellow’ and ‘Durango Yellow’ had similar good performance from high flower ratings, affected by some lower foliage ratings. French double – red/ yellow class: all members of this class had outstanding ratings, but ‘Honeycomb was significantly better.
Note
The information in this report is a summary of experimental results and does not provide recommendations for crop production. Where trade names are used, no discrimination is intended or endorsement implied.
Literature cited
American Horticultural Society. 1999. Heat zone map. 29 Apr. 2002. http://www.ahs.org/publications/heat_zone_map.htm
Florida Automated Weather Network. 2002. FAWN: Florida Automated Weather Network 13 June 2002. http://fawn.ifas.ufl.edu/scripts/reportgen.asp
Howe, T. K. and W. E. Waters. 1997. Evaluation of marigold cultivars for the landscape in west-central Florida. Proc. Fla. State Hort. Soc. 110:350-357.
United States Department of Agriculture, April 2001. Floricultural Crops 2000 Summary. Agricultural Statistics Service Sp Cr 6-1 (01) a. 17 June 2002. http://usda.mannlib.cornell.edu/reports/nassr/other/zfc-bb/flor0401.txt
United States Department of Agriculture, 1998. 1998 Census of Horticultural Specialties. 17 June 2002. http://www.nass.usda.gov/census/census97/horticulture
[1] Variety trials coordinator
[2] Professor of floriculture
[3] Assistant professor of floriculture
