Christopher J. Currey

Herbaceous Perennial Producers Can Grow High-quality Blanket Flower in Bioplastic-based Plant Containers

We quantified the growth and quality of ‘Arizona Sun’ blanket flower (Gaillardia ·grandiflora) grown in different bioplastic containers and characterized the interest of commercial perennial producers in using bioplastic-based biocontainers in their herbaceous perennial production schemes. Plants were grown in three types of #1 trade gallon (0.75 gal) containers at five commercial perennial producers in the upper-midwesternUnited States. Containers included onemade of polylactic acid (PLA) and a proprietary bio-based filler derived from a coproduct of corn ethanol production, a commercially available recycled paper fiber container twice dip-coated with castor oil–based biopolyurethane and a petroleum-based plastic (control) container. Plant growth data were collected when most plants had open flowers, and plant shoots, roots, and containers were rated by commercial grower participants. Questionnaires were administered at the beginning and at the end of the experiment to characterize the perceptions and interest of growers in using these containers, their interest in different bioplastic-based container attributes, and their satisfaction from using the containers. Container type and grower interacted to affect growth index (GI), shoot dry weight (SDW), and container rating. Root rating was affected by container type or grower and shoot rating was unaffected by either. Our results indicate that commercial producers can adapt these bioplastic-based biocontainers to blanket flower production with few or no changes to their crop cultural practices.

Effectiveness of Biopolymer Horticultural Products for Production and Postproduction Nutrient Provision of Garden and Bedding Crops and Container Ornamentals

We evaluated emerging biopolymer horticultural products that provide fertilizer nutrients to plants (fertilizing biocontainers, pelletized biopolymer fertilizer, and biopolymer fertilizer spikes) for their effectiveness during greenhouse production and garden growth of floriculture crops, and during postproduction culture of container ornamentals. Greenhouse experiments (in 4.5-inch containers) and garden trials were performed with tomato (Solanum lycopersicum), pepper (Capsicum annuum), petunia (Petunia ·hybrida), and marigold (Tagetes patula). Postproduction experiments were performed with 12-inch hanging baskets containing lobelia (Lobelia erinus), trailing petunia (Calibrachoa ·hybrida), and petunia, and with 13-inch patio planters containing zonal geranium (Pelargonium ·hortorum), spikes (Cordyline indivisa), bidens (Bidens ferulifolia), and trailing petunia. Although slightly less effective than synthetic controlled-release fertilizer (CRF), all three nutrient-containing biopolymer horticultural products were sufficient and suitable for providing fertilizer nutrients to plants grown in containers and in garden soil. Results of the postproduction experiment provided proof-of-concept for the effectiveness and potential of biopolymer fertilizer spikes as a sustainable method for providing fertilizer nutrients to containerized plants. The current formulation of pelletized biopolymer fertilizer was somewhat more effective for vegetable crops (pepper and tomato) than for floriculture crops (marigold and petunia). For plants produced in 4.5-inch containers, the combination of the fertilizing biocontainerwith no additional fertilizer in the greenhouse, then burying the fertilizing container beneath the plant to degrade and provide nutrients in the garden was very effective. Biopolymer horticultural products represent a promising alternative to petroleum-based plastic containers and synthetic fertilizers. Adoption of some or all of these technologies could improve the environmental sustainability of the horticulture industry without reducing productivity or efficiency, and without increasing labor intensity.

Commercial Greenhouse Growers Can Produce High-quality Bedding Plants in Bioplastic-based Biocontainers

Our objectives were to quantify the growth and quality of herbaceous annuals grown in different types of bioplastic-based biocontainers in commercial greenhouses and quantify producer interest in using these types of biocontainers in their production systems. Seedlings of ‘Serena White’ angelonia (Angelonia angustifolia) and ‘Maverick Red’ zonal geranium (Pelargonium ·hortorum) that had been transplanted into nine different (4.5-inch diameter) container types [eight bioplastic-based biocontainers and a petroleum-based plastic (PP) (control)] were grown at six commercial greenhouses in the uppermidwesternUnited States. Plants were grown alongside other bedding annuals in each commercial greenhouse, and producers employed their standard crop culture practices. Data were collected to characterize growth when most plants were flowering. Questionnaires to quantify producer perceptions and interest in using bioplastic-based biocontainers, interest in different container attributes, and satisfaction were administered at select times during the experiment. Container type interacted with greenhouse to affect angelonia growth index (GI) and shoot dry weight (SDW), as well as shoot, root, and container ratings. Container type or greenhouse affected geranium GI and shoot rating, and their interaction affected SDW, and root and container ratings. These results indicate that commercial producers can grow herbaceous annuals in a range of bioplastic-based biocontainers with few or no changes to their crop culture practices.