Greenhouse and Nursery Water Management Characterization and Research Priorities in the USA

Nursery, floriculture, and propagation production accounted for 79% ($13.3 Billion) of 2017 ornamental specialty crop production in the United States. Access to high quality water sources is increasingly limited for irrigating these economically significant crops. Given the production, environmental, and economic issues associated with the use of water—including recycled, reclaimed, surface, and ground water—it is critical to develop sustainable runoff, containment, and remediation technologies, and to identify alternative sources of water. To better understand current practices and future water-related needs as perceived by grower stakeholders, an online survey was distributed nationally and five in-depth round table discussion sessions were conducted at the Mid-Atlantic Nursery Trade Show, Gulf States Horticultural Expo, California Grown Show, AmericanHort’s Cultivate, and the Farwest Show with a total of 36 individual industry participants. A team of research and extension specialists facilitated by a Specialty Crops Research Initiative Planning Grant (NIFA Project # 2011-51181-30633) analyzed and concisely summarized the results from the survey and the round table discussions. Research priorities related to water management identified by stakeholders revolved around six themes: (1) recycled water infrastructure and management; (2) contaminants; (3) plant health and water quality; (4) water treatment technologies; (5) competing and complementary water uses; (6) societal perception of agricultural water use.

Quantification of Daily Water Requirements of Container-Grown Calathea and Stromanthe Produced in a Shaded Greenhouse

Irrigating plants based on their water requirements enhances water use efficiency and conservation; however, current irrigation practices for container-grown greenhouse plants largely relies on growers’ experiences, resulting in leaching and/or runoff of a large amount of water. To address water requirements of greenhouse-grown plants, this study adapted a canopy closure model and investigated actual evapotranspiration (ETA) of Calathea G. Mey. ‘Silhouette’ and Stromanthe sanguinea Sond. from transplanting to marketable sizes in a shaded greenhouse. The daily ETA per Calathea plant ranged from 3.55 mL to 59.39 mL with a mean cumulative ETA of 4.84 L during a 224 day growth period. The daily ETA of S. sanguinea varied from 7.87 mL to 97.27 mL per plant with a mean cumulative ETA of 6.81 L over a 231 day production period. The best fit models for predicting daily ETA of Calathea and Stromanthe were developed, which had correlation coefficients (r2) of 0.82 and 0.73, respectively. The success in modelling ETA of the two species suggested that the canopy closure model was suitable for quantifying water use of container-grown greenhouse plants. Applying the research-based ETA information in production could reduce water use and improve irrigation efficiency during Calathea and Stromanthe production.