ASHS 2024 Conference

Today’s environmental and social concerns – including climate change and economic inequality – push sustainability to the forefront of many business strategies, from tech companies to grocery retailers to flower farmers. To better understand the scope and limitations of sustainable practices among flower growers, wholesalers, retail florists, and floral suppliers, the research team administered an industry-wide survey. Sections of the survey delve into aspects of floriculture businesses throughout the United States, including scale of operations, current sustainability measures, motivations driving sustainability activities, and barriers preventing sustainable practices. The results indicate strong personal motivations for sustainability measures within floriculture, yet respondents perceived a lack of financial or regulatory incentives to implement such practices. A subset of results for growers are compared to a 2008 survey to assess changes in sustainability practices within domestic flower production over time. Regional variances in perceived access to resources and implementation of sustainability practices will also be discussed. Our study aims to identify key areas where progress has been made or can be made in the industry, including educational efforts and incentives to address the perception of risk when implementing sustainability practices. A subset of results for growers are compared to a 2008 survey to assess changes in sustainability practices over time within domestic flower production. Our study aims to identify key areas where progress has been made or can be made in the industry, including educational efforts to address the perception of risk when implementing sustainability practices and communicating benefits to consumers.

Cut flower production in the Northeastern United States is restricted by a short growing season. This impacts profitability for many growers and reduces the number of flower options available to them. While there is a reduced selection available, it can still be difficult to select which flowers are profitable and high yielding during a short season. For these reasons, field and controlled environment production of a variety of flowers that could be used in bouquets sold at markets or available for events was investigated. An early- and late-season arrangement was designed utilizing six different plants which could be harvested, assembled, and sold as a bouquet. Two synchronized trials occurred in 2024 with one in the field and the other in the greenhouse. The field plants were germinated indoors and transplanted in a full sun location in USDA Hardiness Zone 5a. The greenhouse plants were grown in three systems which included drip irrigated plants in containers with 4:1 coconut coir: parboiled rice husks, drip irrigated containers filled with rockwool GrowCubes, or hydroponic nutrient film technique. Greenhouse and field plants in both trials were assessed for germination rate and timing; time to flower; flower number, stem length, and subjective quality; and vase life utilizing 3 different floral preservatives. Plants grown in the greenhouse were also compared for adaptability to each growing system. Seeds for the early season bouquet were germinated in April and transplanted into their respective systems in May. Seeds for the late season bouquet were germinated in June and transplanted in July. This information can be used by cut flower growers in the Northeast to potentially extend their season and develop a market for designed “grow-a-bouquet” planting strategies.

Bougainvillea spp. a difficult root ornamental plant does not root easily requiring the need for growth regulators. Moreover, the varieties have high aesthetic values and commercial florist desires. Experiments were conducted at the Federal University of Agriculture, Abeokuta Nigeria to determine the effect of varietal differences and cutting length on the rooting ability and growth of Bougainvillea plants. The experiment was a completely randomized design replicated three times. The cutting lengths had a significant effect on the number of leaves produced, with the highest leaf production observed for the 15cm cutting lengths in B. glabra variegata and B. glabra white plants, 5cm cuttings however produced the highest number of leaves in B. spectabilis variety. The cutting length also has a significant effect on the heights produced in the three varieties of Bougainvillea plants where 15cm cutting produced the highest plant heights in B. glabra variegata and B. glabra white varieties which were significantly different from those obtained from the 10cm cuttings, However, 5cm cuttings produced the highest plant heights in B. spectabilis. The interaction effect of cutting length and variety was significant (p

Basil (Ocimum basilicum) is one of the most popular culinary herbs sold in containers, but plants can quickly become tall, leggy, and unmarketable. Chemical plant growth regulators (PGRs) are not labelled for use on herbs, so there is a need for a nonchemical alternative. Ultraviolet radiation (UV) has been shown to be an effective alternative to PGRs on ornamentals, but there are no guidelines for effective use of UVA in potted basil production. Therefore, the objectives of this study were to determine the stage of development plants should be exposed to UVA radiation and the effective duration. Fifteen seeds of either sweet basil cultivars ‘Nufar’ or ‘Genovese’ were sown into 15-cm containers. The containers were placed in a glass-glazed greenhouse at 23 °C and under a 16-h photoperiod (LD) provided by LED supplemental lighting or under a 9-h photoperiod and 6-h night interruption lighting providing 385 nm of UVA radiation at an intensity of 20 µmol∙m–2∙s–1. Seeds were germinated for one week under either LD or UVA and then grown for 3 weeks under 10 treatments. The treatments included: LD entire time, LD 1 week-UV 2 weeks, LD 1.5 Weeks-UV 1.5 Weeks, LD 2 weeks-UV 1 week, LD 1 week-UV 1week-LD 1week, UV entire time, UV 1 week-LD 2 weeks, UV 1.5 weeks-LD 1.5 weeks, UV 2 weeks-LD 1 week, and UV 1 week-LD 1week- UV 1 week. Both cultivars responded differently to UVA radiation. Generally, plants grown under UVA from germination to harvest were the most compact. For example, ‘Genovese’ under UV entire time were 3.6 cm shorter than plants under LD entire. However, the chlorophyll content and dry mass of ‘Genovese’ were reduced by 33 and 53%, respectively, when exposed to UV entire compared to plants under LD entire. Additionally, if the treatment a plant ended under was LD, the chlorophyll content was generally higher than those ending under UV. Therefore, the most compact and green potted basil ‘Nufar’ and ‘Genovese’ were those grown under UV 2 weeks-LD 1 week.

Downy mildew (DM) of impatiens (Impatiens walleriana), caused by the oomycete, Plasmopara obducens, results in chlorosis, defoliation, and significant crop losses. Current management includes fungicides and genetic resistance. We applied photoperiodic light quality treatments to ‘Accent Premium White’ impatiens from seed sowing until flowering to limit DM and enhance plant quality. Seeds were sown in a greenhouse with a day and night greenhouse air temperature set point of 23 °C and a target daily light integral of 12 mol·m–2·d–1. A truncated 9-h short-day (SD) photoperiod was achieved by opening and closing opaque black cloth over individual greenhouse benches. Supplemental light-emitting diode (LED) fixtures provided 120 µmol·m–2·s–1 at plant height. Each bench was randomly assigned to one of nine discreet photoperiod treatments: 9-h SD (control) or 9-h SD extended by continuous 7-h LED fixtures emitting blue (405 nm), blue (445 nm), green (525 nm), red (660 nm), far-red (730 nm), white fixtures provided 100-nm waveband ratio (%) of 18:38:41:3 blue:green:red:far-red radiation, a screw-in LED flowering lamps provided 100-nm waveband ratio (%) of 7.6:15:72.4:5. Additionally, 6-h intermittent (1900 to 2200 HR and 0300 to 0600 HR) LED fixtures emitting ultraviolet-A (385 nm) were assigned to one bench. The total photon flux density was adjusted to 20 µmol·m–2·s–1 at plant height under black out curtains for each treatment. Impatiens were inoculated 70 days post sowing with a P. obducens sporangial suspension (2.6 to 3 x 105 sporangia·mL–1) until runoff on the abaxial side of the leaves. Afterwards, each plant was placed in a clear plastic bag containing 300 mL of Hoagland Solution (50%) and returned to its respective treatment. After 9-10 days post inoculation, the ratio of diseased leaves to the total leaf number was determined. In the initial experimental trial, control plants exposed to a 9-h SD treatment displayed an average disease incidence of 72.7%, while other treatment groups ranged from 30.6 to 98.3%. In the subsequent trial, control plants exposed to the same 9-hr SD treatment showed an average disease incidence of 42.6%, while other treatment groups ranged from 0 to 59.5%.

Floriculture makes up the largest sector of ornamental horticulture production, valued at $6.7 billion and dominated by the production of annual bedding-plants. Production is timed to meet spring market dates, starting during a time of year when ambient outdoor temperatures and daily light integrals are below optimal for high-quality plant production. As a result, heating and supplemental lighting can represent a significant operational and energy cost for producers. Yet, producers and investors of the industry have acknowledged an inability to evaluate their resource use due to a lack of industry-wide benchmarks and key performance indicators (KPIs). Past research has compiled energy and water data from controlled environment agriculture (CEA) and, for floriculture, investigated the potential of energy-efficient production strategies and used life cycle assessments (LCAs) to evaluate the environmental impact of the products produced. However, CEA focuses on food production and both the compiled CEA data and the LCAs are largely based off modeled data. Therefore, this research will validate models utilized in LCAs and carbon footprint studies with experimental data, giving producers additional benchmarks and KPIs to evaluate their operational resource-use efficiency. The objectives of this study were to (1) evaluate the use of supplemental day-extension lighting (SDEL) from two different fixtures [(light-emitting diodes (LEDs) and high-pressure sodium (HPS)] during unrooted cutting (URC) propagation of five annual bedding plants and (2) to quantify the greenhouse energy and water consumption. Unrooted cuttings were received from a commercial propagator and stuck in a 105- (calibrachoa, coleus, impatiens, and petunia) or 72- (geranium) propagation tray filled with a pre-moistened soilless propagation substrate and placed under oner of three SDEL treatments on root-zone heating set to 23℃. Each treatment consisted of a propagation tent for callusing and an adjacent rooting environment. Until adventitious root formation, cuttings were misted with clear water, and then were removed from the propagation tent where they were irrigated daily with 150 mg·L–1 nitrogen provided by 15-5-15 water-soluble fertilizer (JR Peters, Inc.; Allentown, PA). After 21 days, data were collected on rooted cuttings. As expected, the energy-use of HPS-lamps exceed that of the LEDs. However, cutting stem-length and stem and leaf dry mass were decreased under SDEL, resulting in liners that were more compact, uniform, and of higher quality than those propagated under ambient conditions. An opposite trend was observed for root dry mass. This indicates that SDEL is a critical tool when utilized for bedding-plant propagation.

Rooting of herbaceous perennial cuttings occurs year-round in greenhouses under photosynthetic daily light integrals (DLIs) ranging from ≈1–20 mol·m–2·d–1. The effects of DLI on rooting and cutting growth have not been quantified for many vegetatively propagated herbaceous perennials. As such, our objectives were to determine the effects of DLI on adventitious rooting and cutting quality of a popular herbaceous perennial, yarrow (Achillea sp.). Unrooted cuttings of yarrow (Achillea millefolium ‘Apricot Delight’) were received from a commercial cutting supplier and callused in a glass-glazed greenhouse for 5 d under ≈3.6 mol·m–2·d–1 at 24 °C root-zone and air temperatures. Upon callusing, cuttings were transferred to a rooting environment with 21 °C air temperature and 24 °C root-zone temperature set points. Cuttings were rooted under one of four different fixed-woven shadecloth providing ≈86%, 62%, or 26% shade or no shade (0%) thereby establishing mean DLIs ranging from 1.6 to 15.2 mol∙m‒2∙d‒1. Cutting growth and biomass accumulation evaluations were made 8, 11, and 14 d after transfer. In general, yarrow stem caliper, stem length, and leaf number were unaffected by increasing DLI; however, leaf, stem, root, and total biomass accumulation increased with increasing DLI though to different magnitudes. For example, as DLI increased from 1.6 to 15.2 mol∙m‒2∙d‒1, leaf, stem, root, and total biomass accumulation increased by 84%, 85%, 458%, and 93% at 8 days after transfer to 98%, 110%, 893%, and 128% at 14 days after transfer, respectively. When taken together, DLI should be properly managed to hasten and improve rooting and growth of yarrow cuttings during adventitious root development.