Soilless System with Supplementary LED Light to Obtain a High-Quality Out-of-Season Production of Green Beans

Green bean (Phaseolus vulgaris L.) is one of the most important sources vegetable proteins in world and it cultivated all year round, but light availability, during dark season, limited its growth. Nevertheless, recent studies conducted on greenhouse horticulture demonstrated that, with application emitting diodes (LEDs) as supplementary (SL) technology, possible to overcome this limitation. Consequently, experiment conducted, two cultivars green (‘Saporro’ ‘Maestrale’) were grown a soilless system cold fall-winter period. To increase photoperiod daily integral (DLI), early morning, four hours red (R), blue (B) red+blue (R + B) supplied by LEDs at 180 μmol·m−2·s−1 (PPFD) plants level. Plants under improved yield gas exchange compared natural light; when B was sole source SL, increased dry matter content brightness (L*) pods. Between cultivars, ‘Maestrale’ produced 20 g∙plant−1 pods more than ‘Saporro’ latter’s colour brighter greener (a*), also showed highest photosynthetic efficiency (ΦPSII). In conclusion, obtained encouraging out-of-season yields different LED spectra, among those seems improve overall crop performances quality.