Evaluación de extracto de nogal como método preventivo y/o curativo de Botrytis cinerea en cultivo de Fragaria x ananassa var Monterrey

Abstract

Strawberry (Fragaria x ananassa) is a high-value crop, but highly susceptible to fungal diseases such as Botrytis cinerea, which significantly affects fruit production and quality during pre- and postharvest stages. Due to the excessive use of synthetic fungicides, an ethanolic extract from walnut leaves (Juglans neotropica) is proposed as a natural alternative. This study evaluated five concentrations of the extract (0%, 5%, 10%, 15%, and 20%) applied using both preventive and curative methods, under laboratory and field conditions. The results demonstrate that the walnut extract exhibits effective antifungal properties against Botrytis cinerea. In the laboratory, mycelial growth inhibition was observed, with the preventive 15% and curative 10% treatments being the most effective. In the field, curative applications at 15% and 20% significantly improved fruit development (weight, polar and equatorial diameter), highlighting their potential to aid recovery in already infected plants. However, the preventive treatment at 10% was the most consistent and effective in reducing disease incidence and severity over time. Overall, the 10% preventive treatment stands out as the most balanced option, providing phytosanitary protection without compromising fruit quality, while the 20% curative treatment offers a promising strategy for restoring plant development after infection. Both approaches can be used complementarity, depending on the application timing and the crop's health status.