S23 - Session P1 - Pre-harvest supplemental LED light can preserve tomato hardness and carotenoid content during post-harvest storage

Authors: Elisa Appolloni *, Ivan Paucek, Fiori Giovanni, Chiara Pastore, Antonio Cellini, Giuseppina Pennisi, Andrea Crepaldi, Francesco Spinelli, Francesco Orsini, Xavier Gabarrell, Giorgio Gianquinto

Tomatoes ( Solanum lycopersicum ) undergo changes in quality and nutraceutical traits during post-harvest storage. These modifications are also influenced by pre-harvest conditions, including irrigation, fertilization, harvesting stage and light. The present research investigated how pre-harvest supplemental LED interlighting affects post-harvest quality of greenhouse truss-tomatoes (cv 'Siranzo') grown in a soil-less high-wire system. The experiment consisted in the application of three supplemental lighting treatments, while plant cultivated under natural light only were used as control (treatment CK). All light treatments applied in addition to the solar radiation featured a red and blue spectrum (Red:Blue ratio=3, 16 h d -1 , from 08:00 to 00:00, supplying 170 µmol s -1 m -2 ), either alone (treatment RB) or with addition of 40 mmol m -2 s -1 of Far-Red light either throughout the photoperiodic day (16 h d -1 , treatment FR) or for half-hour only at the end of the day (from 00:00 to 00:30, treatment EOD). After harvesting, red-ripen fruit were placed in a storage room at 13 °C in the darkness. Sensorial quality (e.g., fruit firmness, titrable acidity, total soluble solids, colorimetric indexes) and carotenoids content (lycopene and B-carotene) were assessed at the beginning and after 1 week storage. Fruit firmness was reduced during storage in all treatments, although to a lower extent in fruit from plants supplied with RB and FR, than the one grown under EOD and CK treatments. Carotenoids content (lycopene and β-carotene) showed a significantly lower reduction in RB than to other treatments. The study confirms that greenhouse supplemental lighting may result in significant improvement of tomatoes qualitative traits during also post-harvest.