The potential to improve culinary herb crop quality with deficit irrigation

Abstract

Abstract Irrigation, the practice of artificially supplementing the water available to crops, accounts for 70% of global freshwater abstractions. Since water supply is increasingly under threat from climate change, implementing novel deficit irrigation techniques - the practice of applying less than the optimum amount of water required by the crop- is a pressing priority for future horticulture. Several studies show that deficit irrigation not only saves water, but may also improve crop quality, for example in fruit trees, wine grapes and culinary herbs such as mint. Here we synthesise current knowledge and practice on irrigation in herb crop production, since dietary trends in recent decades have shown a rise in popularity of fresh produce including culinary herbs, but there has been little progress in developing irrigation techniques and scheduling in such crops. We find strong evidence that water deficit can improve crop quality for several leafy herb crops. This includes increase in essential oils, aroma and quality, alongside increases in the plant metabolites that contribute to antioxidant potential. Despite these positive findings, this review also highlights a gap in understanding the application of deficit irrigation technologies to commercial herb crop systems and suggests further innovation and research is required in this area of precision horticulture.