Improved production and quality of peppers irrigated with regenerated water by the application of 24-epibrassinolide

Water shortage for crop irrigation is reducing agricultural production worldwide and the use of sewage treatment plant (STP) water to irrigate horticultural fields is a solution to avoid the use of drinkable water in agriculture. In this study, two different genotypes of pepper (Red Cherry Small and Italian green) were irrigated with STP water, as an alternative to potable water. Moreover, the foliar application of a molecule with biostimulant properties (24-epibrassinolide; EBR) was tested as a strategy to ameliorate the production and quality of fruits. Both genotypes differed on their tolerance to the suffered oxidative stress due to their different salinity tolerance, but fruit commercial weight was reduced by 49% on the salt sensitive and by 37% on the salt tolerant. Moreover, ascorbic acid was also decreased by 37% after STP water irrigation in the Red Cherry Small peppers. However, EBR applications alleviated STP watering stress effects improving pepper plants fruit production and quality parameters, such as ascorbic acid and capsaicinoids. These results have important economic and environmental relevance to overcome present and future water deficiencies in the agricultural sector derived from climate change, guaranteeing the maintenance of production in peppers irrigated with STP water for a more sustainable agriculture following relevant circular economy actions.

Automated summary

Water shortage in crop irrigation is decreasing global agricultural production. Using sewage treatment plant (STP) water to irrigate horticultural fields is a solution to avoid using drinkable water in agriculture. In this study, two genotypes of pepper were irrigated with STP water and a biostimulant molecule was tested to improve fruit quality and production. Results showed that the genotypes differed in their tolerance to oxidative stress, but the use of STP water reduced commercial weight and ascorbic acid in peppers. However, the application of the biostimulant alleviated the negative effects of STP watering and improved fruit quality. These findings are important for overcoming water deficiencies in agriculture and promoting sustainable practices.