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.
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).
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).
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.
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).
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.
Plants of Salvia leucantha were subjected to 8, 10, 12, or 14 hr of light under controlled environmental conditions. Salvia leucantha is a short-day plant with a critical photoperiod of 12 hr for macrobud development, but 10 hr for subsequent flower development. About 14 photoperiodic cycles are necessary for flower initiation, but at least 42 cycles are required for normal anthesis and raceme elongation. Apices that had initiated under < 6 weeks of short days failed to develop when placed under long days. Flower initiation did not occur when night break lighting of 1.3 μmol·s−1·m−2 was provided by incandescent lamps.
A copper hydroxide formulation (0%, 3.5%, 7%, 11% Cu) was applied to plug trays before sowing seeds of Impatiens ×hybrida L. `Accent Red', Pelargonium ×hortorum Bailey `Scarlet Elite', and Petunia ×hybrida Hort.Vilm.-Andr. `Ultra White' to investigate the influence of the formulations on ease of transplant, root growth, and shoot growth. These factors also were investigated in Cu-treated seedling plugs held past optimal transplanting stage. Root spiraling and seedling height at transplant were reduced for all taxa grown in Cu-treated trays, regardless of concentration, compared to seedlings from nontreated trays. Root weight and shoot weight responses to Cu treatments at transplant and at flowering varied among taxa. Mature heights of all taxa were unaffected by Cu treatment; however, flowering date was delayed for impatiens and geraniums transplanted at optimal time from Cu-treated trays. In general, petunias displayed little response to Cu treatment. Root spiraling was reduced and plugs were removed more easily from Cu-treated than from control trays stored for 2 weeks in the greenhouse, but flowering time was delayed for 12 days for impatiens and petunias and 21 days for geraniums, regardless of Cu concentration.
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.
Various bulbous species were planted during the fall and winter in an attempt to extend harvest periods of cut flowers. In the first year, late planting resulted in later flowering, but shorter stems and reduced yield than early planting; however, some responses were species specific. No differences in flowering due to initial planting times occurred in the subsequent 2 years, regardless of species tested. Anemone coronaria L. and Acidanthera murielae Hoog. ex Perry were productive for 1 year only, but Allium sphaerocephalum L., Brodiaea laxa Wats., and Crocosmia × crocosmiiflora (V.Lem. ex E. Morr.) N.E. Br. were productive for 2 to 3 years. The peak harvest for anemones was 3 to 5 weeks from beginning of harvest, depending on cultivar, and 10 to 20 days from beginning of harvest for crocosmia. Anemone `Mona Lisa' produced longer stems and larger flowers and flowered earlier than `De Caen'.