Recipient Organization
NORTH CAROLINA STATE UNIV
(N/A)
RALEIGH,NC 27695
Performing Department
Horticultural Science
Non Technical Summary
Cut flowers are an important part of our culture and economy. Cut flower production in the United States has resurged for many reasons, with one of the most important being increasing interest in purchasing locally grown products. The number of members of the national Association of Specialty Cut Flower Growers (ASCFG) has increased from approximately 500 from 1996 to 2014 to 1650 in 2019. To support this industry, information is needed on new cut flowers and how to economically produce and handle them after harvest. Cut flowers have to be produced in a sustainable, economically viable system, harvested at the optimum stage, and properly handled, stored and shipped to the customer. In addition, many new cut flower species and cultivars are released each year and need to be evaluated to determine if they are commercially viable. Our project focuses on 1. Screening new cut flowers species and cultivars to select those which are productive, marketable and long-lived after harvest. 2. Developing cost effective production protocols for cut flower species and cultivars. 3. Determining optimum postharvest handling procedures for cut flower species and cultivars including ethylene sensitivity and optimum cold storage duration, pretreatments and pulses; vase solutions and substrates; and commercial preservatives.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
Cut flower production in the United States and Canada has resurged in recent years, led by small to medium-sized farms that are mostly family owned. Illustrating this phenomenon is the fact that the number of members of the Association of Specialty Cut Flower Growers (ASCFG) has increased from approximately 500 from 1996 to 2014 to 1670 in 2019 (J. Laushman, personal communication). These farms are selling their product through a variety of marketing avenues. Many sell flowers directly to consumers through farmers markets, farm stands, or subscription services; others sell their flowers to florists, specialty supermarkets, bucket trucks, and/or wholesalers. One of the most rapidly growing categories is that of the farmer/florist - integrated businesses that provide floral design services primarily using the cut flowers, foliages, fruits and stems they produce.The trend in American agriculture to buy local has been one of the factors supporting the resurgence in cut flower production. These new businesses are focusing on the production and use of specialty cut flowers, as compared to species grown offshore, such as roses, carnations, alstroemeria, and chrysanthemums, that are shipped into the United States and Canada. Hundreds of species can be grown commercially as cut flowers (Dole et al., 2017). In North Carolina alone, more than 75 different species of cut flowers are grown (Granitz, 2014). A recent national survey resulted in a list of 130 species being grown in the United States and Canada (Loyola et al., 2019).Cut flowers are a high value specialty crop that is well suited to North Carolina due to its large population, which encourages high retail sales, and its location, which encourages high wholesale sales because it is within a one-day (12 hours or less) shipping distance of much of the Eastern United States population from Boston south to Washington, D.C. Specialty cuts are grown either in fully controlled environment greenhouses, high tunnels with modest environmental control, or outdoors in field beds. Gross value of production from field cut flower operations ranges from $5,000 to $30,000/acre.Each year a wide variety of new species and cultivars are made available from plant breeders, propagators, and suppliers. Unfortunately, little information is available on the production requirements of most new crops. While every firm typically conducts in-house research at some level, firms rarely have sufficient time and labor for proper evaluation. New cultivars are usually tested in limited quantities and often receive less production care than major income generating crops grown in large quantities. Secondly, the typical firm does not have sufficient space to evaluate a large number of new cultivars. On the other hand, industry plant suppliers regularly test products at their own facilities and at commercial growers around the country, but the results are often proprietary and may not receive wide distribution. University-administered trial programs are a well-established, public method for evaluating the commercial viability of new plant materials and distributing information regarding their marketability and production needs (Dole and Laushman, 2013).Once new species or cultivars show potential, production protocols need to be developed. Cost effective production of new crops often requires information on rapid propagation, establishment, flowering and branching techniques. New species and cultivars may have specific flowering protocols, which must be elucidated and controlled to inhibit flowering during propagation and promote flowering during production. Nutritional regimes, pest control methods, and production schedules may need to be determined. In addition, cut flowers need to have long, sturdy stems and long-lasting flowers. All production practices also need to be evaluated in terms of costs. Production techniques can be developed to produce a high-quality crop but may be too expensive to be commercially viable.Finally, many new floriculture taxa are attractive and easy to produce, but do not make successful commercial floriculture crops because of poor postharvest qualities. For example, the bearded iris (Iris ×germanica) is a spectacular and well-loved garden perennial that has too short of a vase life and is too delicate to withstand the rigors of commercial marketing. Testing is required to determine if new crops have the proper postharvest characteristics for commercial production and for use by the final consumer as cut flowers (Clark et al., 2010; Dole et al., 2013, 2015)The goals of this project are to 1. Screen new cut flowers species and cultivars to select those which are productive, marketable and long-lived. 2. Develop cost effective production protocols for cut flower species and cultivars. 3. Determine optimum postharvest handling procedures for cut flower species and cultivars including ethylene sensitivity and optimum cold storage duration, pretreatments and pulses; vase solutions and substrates; and commercial preservatives.
Project Methods
Evaluation of New Species and CultivarsNC State evaluates 20 to 70 new cultivars annually for greenhouse and field production through The National Annual and Perennial Cut Flower Trial Programs, in cooperation with the Association of Specialty Cut Flower Growers (ASCFG) (Dole and Laushman, 2013). In addition to being evaluated at NC State, the cultivars are tested at 20 to 35 locations in the United States and Canada. Participants in the trials return evaluation reports on each cultivar. The information obtained includes yield per plant, average stem length, planting density, and several ratings (1-5, with 5 best). The ratings include 1. ease of production, 2. "grow again", which refers to how likely the participant is to produce the plant on a commercial level next year, and 3. market appreciation by the general public, retailers and wholesalers. In addition, participants have the opportunity to comment on the good qualities, poor qualities and postharvest life of each cultivar. At NC State each new cultivar is evaluated in raised beds, 1.2 m wide and 5 to 10 cm high. Plants are spaced at 30 x 30 cm, irrigated as needed with drip irrigation. The soil is amended prior to planting with 112 kg ammonium nitrate/hectare and as needed after planting with 100 mg/L N applied in the irrigation water from a commercial 20-10-20 fertilizer. Stems are harvested three times per week, and length and number of stems recorded.Development of Production ProtocolsSeed of promising new cut flower species and cultivars will be directly sown into 105 plug flats using a peat-lite commercial root substrate for germination at 16+1oC. One half of plants will receive 8-h of HID supplemental lighting and the other half of plants will not receive supplemental HID. Seedlings will be transplanted into 15-cm pots spaced at 15 x 15 cm at the appearance of 2-3, 5-6, or 8-9 true leaves and placed at 5, 10, or 15+1 C night temperatures. Day temperatures will be 3-6 C higher than night temperatures. Plants will be fertigated with 150 mg/L N from a premixed commercial 20N-10P-20K fertilizer during the week and irrigated with just water on the weekends. Data will be collected at harvest and will include stem length, stem diameter, number of flowering plants and anthesis date. Flowers will be harvested when they reach the marketable stage for the species. A 2 x 3 x 3 factorial treatment combination will be used with two light intensities, three transplant stages, and three production temperatures. Three replications of four plants will be used for each treatment combination. Estimated profit/loss per treatment will be calculated (gross sales less production expenses). Production expenses will be calculated as variable costs (seed, flat, and substrate expenses) + overhead costs [$0.418/m2/day (area in plug flat (m2) * days)] + [$0.0048/m2/day (area in production area (m2) * days)]. Overhead costs for plug production are estimated at $0.418/m2/day as determined from Weddington (2003) for wholesale bedding/potted plant producers and adjusted by the consumer price index (U.S. Bureau of the Census, 2014). In addition, estimated heating costs will be determined using Virtual Grower (USDA, Toledo, OH). Gross sales per crate = $/stem*15*percentage of each replication producing marketable flowers. The $/plant will be based on sales of the flowers generated in this study to retail florists and specialty supermarkets through a cooperating commercial cut flower grower.Determination of Postharvest Handling ProceduresThe cut flower research process will consist of two stages. Stage I. Each year 20 to 70 new cut flower cultivars are evaluated through the ongoing ASCFG National Annual and Perennial Cut Flower Trial Programs, administered by the Association of Specialty Cut Flower Growers and NC State University. During the evaluations we will conduct an initial postharvest screening on the most promising 10 to 15 species/cultivars. Based on producer recommendations, we will also evaluate other cultivars as time and space allow. Since each new cultivar will be available in limited quantities, only a few treatments can be conducted to determine general postharvest suitability. Stage II. The most promising species from the previous year will be produced in large quantities and subjected to extensive postharvest testing as in Ahmad and Dole (2015), Carlson and Dole (2010, 2013) and França et al. (2017). General procedures for Stages I and II. Cut stems will be harvested, recut under water, and placed in the appropriate treatments. Unless otherwise indicated, the floral solution used in all experiments will be 21 C deionized (DI) water. After treatment, stems will be placed at 20+2 C under approximately 20 micromol/m2/s light for 12 h day. Vase life after removal from treatment and total solution uptake will be measured for each stem. The pH and EC of solutions at beginning and end of treatment will be measured. A completely randomized design will be used with 15 repetitions (flower stems) per treatment; treatments will be arranged in a factorial where appropriate. Stage I treatments: Cut stems of new cut flowers showing promising production characteristics will be pretreated with either a commercial hydrating solution or DI water and placed in either a commercial holding solution or DI water. For Stage II treatments, cut stems will be place in one to several treatments as follows: Ethylene sensitivity. Cut stems will be placed in DI water and subjected to 0, 0.1 or 1.0 ml/L ethylene for 16 hours. Stems will be pretreated with STS, 1-MCP, or floral solution (control) prior to ethylene treatment. Cold storage duration. Cut stems will be held 0, 1, 2, or 3 weeks in a 2 C cooler (RH 80-90%) either in boxes or in water. The 0-week storage stems will be placed directly into floral vases. At weeks 1, 2, and 3, fifteen stems will be randomly selected from each treatment, recut under water, and placed in floral vases filled with DI water. All remaining stems will be recut under water and placed back into their respective treatments. Pretreatments and pulses. Cut stems will receive a 24-hour pulse treatment of 0, 10 or 20% sucrose plus 0.007 mL/L isothiazolinone (bactericide) in DI water. Vase solutions and substrates. Cut stems will be placed in vases with or without floral foam and in 0, 2, or 4% sucrose plus 0.007 mL/L isothiazolinone. Commercial preservatives. Cut stems will be pretreated with one of three solutions: two commercial hydrating solutions or DI water and placed in one of three holding solutions: two commercial holding solutions or DI water.