The ‘LIGHT CASCADE^®’ sunlight photoconversion greenhouse films increase berries production and provide a better resistance toward biotic and abiotic stresses in Mediterranean countries

Sunlight optimization is a natural and environmentally friendly strategy to improve greenhouse cultivated crop productions. Recent insights highlighted many benefits of light spectrum modulation on marketable yields and fruit quality but also on plant resistance to some biotic and abiotic stresses. Since 2012, the French company CASCADE optimized the ‘LIGHT CASCADE^®’ (LC^®) technology to adapt the sunlight spectrum to different greenhouse cultivated crops. Once incorporated into plastic foils, the technology absorbs UV and green wavelengths and reemits respectively into blue (400-500 nm) and red (600-700 nm) wavelengths. This study is aiming at evaluating the effects of LC^® greenhouse films on the production of Mediterranean raspberries and strawberries from 2018 to 2021. The trials were performed at the ADESVA experimental farm in Huelva (Spain) under classic and reduced fertigation systems. Fruit production precocity, cumulative marketable yield and fruit sugar content were measured. Main results showed that under classic fertigation early raspberry marketable yields increased between +13 and +15.7% and the final marketable yield from +13 to +14.5% under the LC^® films in comparison to the reference film. Soluble sugars quantification performed on fruits harvested at the beginning of the production highlighted an increase of +0.5 °Brix. Under reduced fertigation, strawberries final marketable yield increased up to +9%. Plants pests and diseases have also been quantified during the trials when they occurred. The number of aphids (Aphis gossypii) on raspberries was lowered by -39 and by -62% under LC^® films in 2020 and 2021, respectively. On strawberries, the number of thrips (Scirtothrips aurantii) per plant was reduced by -12.5% and the percentage of infected plants by powdery mildew (Sphaerotheca macularis) by -5.3%. These results provide new insights on sunlight spectrum modulation effects on berry crop yields, fruit quality and resistance toward biotic and abiotic stresses.