Effectiveness of biopolymer horticultural products for production and postproduction nutrient provision of garden and bedding crops and container ornamentals

Abstract

SUMMARY. 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 combi-nation of the fertilizing biocontainer with 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 pro-ductivity or efficiency, and without increasing labor intensity.