Shading Net and Grafting Reduce Losses by Environmental Stresses during Vegetables Production and Storage ^†

The aim of this review is to summarize our recently reported findings on the use of preharvest treatments (shade nets), applied either directly or in combination with other techniques (grafting) in order to minimize physiological disorders and maximize and maintain the phytochemical content of vegetables. The use of coloured nets for shading vegetables to protect against stress (intense solar radiation, heat stress, drought, drying winds and hailstorms) during the summer months is an effective and inexpensive method, and it provides plant protection and altered microclimate and modified intensity and quality of light. Moreover, the use of coloured nets supports a more intensive vegetative growth, longer vegetation and increased yield, and it reduces a number of physiological disorders while improving the morphological and nutritional quality of vegetables. Under colour nets, tomato plants provided fruits with thicker pericarp, firmness, a higher content of lycopene, a lower percent of physiological disorders and better tolerance to transport and storage. Shade-grown plants generally have higher total chlorophyll and carotenoid contents, an increase in the total yield and a decrease in physiological disorders accompanied with an increase in the content of total phenolic compounds and flavonoids. Grafting can increase yield and fruit size and improve or reduce external and/or internal fruit quality and retained better postharvest quality compared to the fruits from non-grafted plants. Further investigations using shade nets alone or in combination with grafting are needed to ensure the use of adequate strategies for managing plant growth of different plant species with limited physiological disorders for increased marketable yield and for maintaining quality during storage.