LAUSR

BACKGROUND Due to the ineffectiveness of existing control methods against Verticillium dahliae, the causal agent of Verticillium wilt of olive (Olea europaea; VWO), it is necessary to search for sustainable and environmentally friendly alternatives such as bioprotection by products based on plant extracts and other naturally synthesized compounds. Therefore, the main objective of this study was to evaluate the effects of seven natural-based commercial products on the inhibition of mycelial growth, the germination of V. dahliae conidia and microsclerotia, and disease progression in olive plants (cv. Picual). Aluminium lignosulfonate and a copper phosphonate salt (copper phosphite) were included for comparative purposes. RESULTS The seaweed and willow extracts and copper phosphite inhibited V. dahliae mycelial growth by more than 50% at the high doses tested. Most of the products inhibited conidial germination up to 90% compared to the control at the high doses tested. However, none of the products showed efficacy above 50% in inhibiting microsclerotia (MS) germination. The willow extract was the most effective at reducing disease severity and progression in olive plants, with no significant differences compared to the noninoculated negative control. CONCLUSIONS The results of this study suggest that the use of natural-based products, i.e., seaweed and willow extracts, is a potential sustainable alternative in an integrated VWO control strategy. This article is protected by copyright. All rights reserved.