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ARS Home » Midwest Area » Wooster, Ohio » Application Technology Research » Research » Publications at this Location » Publication #415579

Research Project: Sustainable Production and Pest Management Practices for Nursery, Greenhouse, and Protected Culture Crops

Location: Application Technology Research

Title: A comparison of photosynthetic light response curves of nine tomato cultuvars

Author
item Boldt, Jennifer

Submitted to: Acta horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/11/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Greenhouses often use electric lights during winter to supplement sunlight and provide enough light to meet crop yield targets. Electric lighting can be a significant production cost. Therefore, supplying light more-efficiently to plants or selecting plants with higher light use efficiencies will increase the utilization of this expensive resource. Photosynthetic curves modeled for nine tomato cultivars in response to light intensity showed that all cultivars had similar light use efficiencies. This indicates that increased fixture efficiency and managing the greenhouse environment to provide ideal growing conditions will have a larger impact on increasing light use efficiency than cultivar selection in tomato.

Technical Abstract: Electric lighting can be a considerable input cost in controlled environment production, depending on crop, geographic location, and time of year. Cultivars often vary in their response to environmental conditions, including light intensity. Assessing cultivar variability can help develop lighting recommendations, as well as identify potential traits that could be selected to improve light use efficiency. The objective of this study was to develop photosynthetic light response curves for tomato (Solanum lycopersicum). Nine cultivars (‘BHN 589’, ‘Brandywine’, ‘Cobra’, ‘Frederik’, ‘Glacier’, ‘Martha Washington’, ‘Rebelski’, ‘Tasti-Lee’, and ‘Valley Girl’) were selected to encompass different recommended growing environments (e.g., controlled environment or field), leaf shape (simple or compound), growth habit (determinate or indeterminate), and fruit type (standard or heirloom). Plants were grown in 12.7-cm pots containing a peat-based soilless substrate. Growth chamber conditions provided an average daily air temperature of 22.4 ± 0.1 °C, ~50% relative humidity, a 16 h photoperiod, and a daily light integral of 17.3 mol·m-2·d-1. Once plants began to flower, photosynthetic light response curves were conducted on one recently-mature, fully-expanded leaf from six plants per cultivar. Cuvette conditions matched the growth chamber, except for light intensity, which varied from 0 to 2000 µmol·m-2·s-1 photosynthetic photon flux density (PPFD). Maximum photosynthetic rate (Amax) ranged from 13.3 ± 0.4 to 18.8 ± 0.7 µmol·m-2·s-1 CO2 (‘Rebelski’ and ‘BHN 589’, respectively), quantum use efficiency (f) ranged from 0.064 ± 0.003 to 0.074 ± 0.003 (‘Rebelski’ and ‘BHN 589’, respectively), and the light compensation point (LCP) ranged from 11 ± 2 to 20 ± 2 µmol·m-2·s-1 PPFD (‘Valley Girl’ and ‘Frederik’, respectively). Across the nine cultivars evaluated, Amax and f were positively correlated (r = 0.80). This study suggests a similar return on investment, with regards to photosynthesis, for supplemental lighting below saturating intensities in the cultivars evaluated.