Various species and selections of Achillea L. were grown for 2 to 5 years, depending on taxon, and evaluated for cut flower yield and quality. `Coronation Gold' yarrow (A. × `Coronation Gold') was productive for 5 years. Flower yield, average stem diameter, and stem length were smallest the first year, but no differences occurred between years 2 and 5. The highest percentage of stems > 50 cm long occurred on plants at the densest spacing. Yields were higher and stems longer for A. millefolium L. cultivars and A. ptarmica L. `The Pearl' in the second than the first year. A. millefolium `Kelwayi' and `Lilac Beauty' produced the highest yield while `Heidi' and `Sawa Sawa' produced the longest stems. Yields of all cultivars of Galaxy hybrids (A. taygetea Boiss. & Heldr. × A. millefolium) increased over 4 years of harvest. Stems were longer and flower diameters were larger after the 2nd year for all cultivars but `The Beacon'. `Salmon Beauty' had the highest yield, but yield of `Appleblossom' did not increase after year 2.
Various field-grown specialty cut-flower species were subjected to full sun or 55% or 67% shade treatments for 2 to 3 years. Plants grown in shade had longer flower stems than those grown in ambient irradiance; however, yield (flower stems per plant) was species-dependent. Yield of Centaurea americana Nutt. `Jolly Joker', an annual speices, and Eryngium planum L., a perennial, declined linearly with each reduction in irradiance. However, yield of Echinops ritro L. `Taplow Blue', a perennial species, was higher in 55% shade than in ambient irradiance. Yield of transplants and tubers of Anemone coronaria L. `De Caen' were not affected by planting material (transplants or tubers). Plants grown under 67% shade had the longest stems starting 3 weeks after the beginning of harvest and the difference persisted for an additional 4 weeks regardless of planting material. A quadratic decline in yield in three of four cultivars of Zantedeschia Spreng. occurred as shade increased, but yield was similar for ambient and 55% shade. Scape length and spathe width increased as shade increased, although some cultivars were more responsive than others.
A. M. Armitage
Achillea ‘Coronation Gold’, A. millefolium L. ‘Rose Beauty’, Physostegia virginiana L.' Liatris pycnostachya Michx., and Salvia leucantha Cav. were planted on 30-, 60-, 90-, or 120-cm centers. Data were collected for 2 or 3 years, depending on species. In all instances the number of flowering stems per plant increased but the number of stems per square meter decreased as spacing increased with time. Stem lengths of Achillea ‘Coronation Gold’, A. millefolium ‘Rose Beauty’, and Physostegia virginiana were affected signficantly by spacing but flower size and stem diameter remained unchanged regardless of planting distance.
A. M. Armitage
Fruit ripening of ornamental pepper (Capsicum annuum L.) was accelerated by the application of ethephon 3 to 6 weeks after anthesis. Concentrations as low as 75 μ1·liter−1 were effective, but 600 μ1·liter−1 resulted in foliar and fruit damage. Concentrations of 150 and 300 μ1·liter−1 were most effective, regardless of cultivar. Fruit <3 cm long were less sensitive to ethephon than more mature fruit. Raising the pH of the treatment solution from 3.3 to 6.3 resulted in increased effectiveness of the chemical, mainly due to an increased response by the larger fruit. Production time was reduced ≈1 day for every 5% increase in colored fruit due to ethephon. Chemical names used: 2-(chloroethyl)phosphonic acid (ethephon).
A. M. Armitage
Application of 1500 ppm chlormequat (CCC) prior to flower initiation accelerated flowering in hybrid geranium, but not when applied after flowers had initiated. The addition of 10 ppm GA3 to the chlormequat resulted in the same flowering time as control plants when applied prior to flower initiation. Fifty and 250 ppm GA3 retarded flowering time when applied prior to or after flower initiation. The data indicate that one of the reasons for early flowering due to CCC is that CCC may suppress endogenous GA levels. Exogenous GA3 increased flower diameter when applied only after flower initiation and increased plant height regardless of time of application. Increasing GA3 concentration generally resulted in a linear trend for time to flower, flower diameter, and nodes to peduncle regardless of time of application. Chemical name used: 2-chloro-N,N,N-trimethylethanaminium chloride (chlormequat).
A. M. Armitage
New crops for pot plant and cut flower production are perhaps in greater demand in this country now than ever before. European research programs for new cultivars have generally been ahead of those here and a greater range of crops is commonly produced by European growers than in America. Research results from European countries are not often published in readily available journals and are difficult to translate, and production data often pertain only to the environment in which the plants were produced. (15).
A.M. Armitage and Meg Green
The University of Georgia trial garden has been in existence since 1982, and the method of evaluation and distribution of taxa has evolved over the years. Annual and perennial taxa are evaluated systematically, over the entire season, providing season-long summaries for each one. Annuals are evaluated every 2 weeks, and scores are based on plant performance, including foliar health, flower numbers and the appearance of disease and insect damage. Perennials are evaluated similarly, however flowering time, flowering persistence and height in the landscape are also noted. Summaries for each taxon are presented in tabular and graphic form. Many new crops have been evaluated and introduced to the floriculture industry. New crops are placed in the horticulture gardens and evaluated by garden personnel and by commercial growers and landscapers. Plants have been distributed free of charge to propagators and growers, resulting in rapid market acceptance of successful taxa.
M. P. Kaczperski and A. M. Armitage
The effects of differing storage conditions prior to transplanting were examined for Salvia splendens `Red Hot Sally', Impatiens wallerana `Super Elfin White', Viola × wittrockiana `Universal Beaconsfield' and Petunia × hybrida `Supercascade Lilac'. Plug-grown seedlings were stored for 0, 1, 2 or 3 weeks at 5C or 10C and irradiance levels from incandescent bulbs at 0, 2 or 12 μmol s-1 m-2. A second group of plants were stored at 18C and irradiance from fluorescent bulbs at 105 μmol s-1 m-2 for the same time period. Temperature was more important than irradiance in maintaining plant quality over the storage period. Impatiens and salvia could be stored successfully for a minimum of 2 weeks at 5 or 10C with no appreciable loss of quality, petunia and pansy up to 3 weeks. Seedlings of all species showed diminished quality when stored longer than 1 week at 18C. After storage, petunias stored at 18C flowered sooner than those stored at 5 or 10C. However, these plants were single stemmed, with long internodes and few flowers while those plants stored at 5 or 10C developed multiple branching and a short, compact growth habit at flowering.
A.M. Armitage and J.M. Laushman
Bulbous roots of Kansas gayfeather or liatris (Liatris spicata Wind.), tuberose (Polianthes tuberosa L.), and Dutch iris (Iris × hollandica) were planted between Nov. 1986 and Mar. 1987. Late planting extended harvest times and resulted in highest yields and longest stem lengths for Liatris spicata and Polianthes tuberosa, but. results were cultivar-dependent with Iris × hollandica hybrids. Yield was highest for all cultivars of Dutch iris except `White Bell' when bulbs were planted in December. Late planting extended harvest time but reduced yield for all cultivars except `White Wedgwood'. No differences due to planting time occurred after the first season for liatris and tuberose, but both species had higher yields the years after initial planting and may be left undisturbed for at least 3 years. Iris flowers were destroyed by late frosts in two successive years and longevity could not be determined. The yield and stem length were optimum for Liatris 10 to 15 days from beginning of harvest, 4 to 5 weeks for single-flowered tuberose, and 5 to 6 weeks from start of harvest for double tuberose. Stem length of tuberose increased over the seasons, regardless of cultivar.
M.P. Kaczperski and A.M. Armitage
The effects of storage conditions before transplanting were examined for Petunia × hybrida Vilm. `Supercascade Lilac', viola × wittrockiana Gams `Universal Beaconsfield', and Salvia splendens F. Sellow ex Roem. & Schult `Red Hot Sally'. Plug grown seedlings were stored for 0, 7, 14, or 21 days at 5 or 10C and with continuous irradiance levels from incandescent bulbs at 0, 2, or 12 μmol·m-2·s-1. A second group was stored at 18C with irradiance from fluorescent bulbs at 105 μmol·m-2·s-1 and a 16-hour photoperiod for the same durations. Temperature was more important than irradiance in maintaining a commercially acceptable plant during the storage period. Petunia and pansy could be stored successfully for 21 days at 5 or 10C with no appreciable loss of quality; salvia could be stored for a minimum of 14 days. Seedlings of all species elongated excessively when stored >7 days at 18C and 105 μmol·m-2·s-1 irradiance. After 14 days of storage, petunias stored at 18C flowered sooner than those stored at 5 or 10C but time in a production environment (days to flower - days in storage) was similar for petunias stored at 5 or 18C.