# Foliar Application of a Biostimulant Based on Fermented Pomegranate Waste Increases Tomato Yield in Greenhouse

## TL;DR

Using fermented pomegranate waste as a biostimulant improves tomato yield and nutritional quality in greenhouse conditions.

## Contribution

This study introduces a novel biostimulant made from fermented pomegranate waste to enhance tomato growth and fruit quality.

## Key findings

- Fermented pomegranate waste increased antioxidant activity and catechin content by 467% and 315%, respectively.
- Application of the fermented extract led to a 34% increase in tomato crop yield and 32% higher lycopene content in fruits.

## Abstract

The use of biostimulants can help to mitigate the conditions of biotic and abiotic stresses in crops by enhancing the crop yield and product nutrients. The novelty of this research was to produce a biostimulant for the tomato cultivation through fermentation of pomegranate waste, evaluating in the crop the effect on the growth, development, and quality of tomato fruits. Pomegranate bagasse was used as a substrate during the liquid fermentation using Aspergillus niger M4 strain. Three applications of fermented extract were made in three phenological crop stages for each of the four different treatments. The biotechnological process allowed the transformation of pomegranate residues, increasing the content of antioxidant activity and catechin in 467% and 315%, respectively. The fermentation enabled the mineral content modification, such as the condensed tannins, zinc, magnesium, and antioxidant capacity. By applying the fermented extract of pomegranate, an increase of 34% in crop yield and a 32% in the lycopene content in tomato fruit was obtained. The use of a fermentative process enables the pomegranate waste mineral modification, enhancing the biostimulant capacity of pomegranate residues. The foliar application of a raw pomegranate fermented extract increases the crop yield and nutritional quality of the tomato fruits.