Red grips the mind: Potential horticultural techniques to increase anthocyanins in fruit skin and pulp

Nowadays consumers demand fruits with attractive and bright colours. Indeed, the market segment related to red coloured fruit has constantly been increasing in the last few years. The reddish colouration in fruits is mainly attributable to the presence of particular water-soluble pigments, the anthocyanins. Various horticultural techniques were used to improve anthocyanin content in fruits: i) increasing the light penetrat- ing inside the canopy; ii) using spraying products; iii) regulating the irrigations; iv) affecting the plant source/sink balance. Among these hor- ticultural techniques, the use of calcium-based sprays and regulated defi- cit irrigations could represent for growers a good compromise between cost and benefits to increase the red colouration in fruit. Nevertheless, further molecular and physiological studies should be conducted, since each species can have distinct physiological regulatory mechanisms. This mini review could help growers to adopt the most effective horti- cultural technique on the base of the plant species prerogatives.