2019 ASHS Annual Conference

The soil borne fungal pathogen, Verticillium dahliae, can remain viable in soil for more than ten years until germination is precipitated by the presence of roots. Previous studies suggest that raw olive pomace and olive pomace composted with other green wastes may provide suppressive action against V. dahliae in soil. Raw olive pomace and the composted product were applied as treatments at a grower standard rate of 8 tons per acre by mixing into a soil artificially contaminated with V. dahliae. The efficacy of both amendments was determined using soil assays. After allowing the amendments to react with the contaminated soil, six-month old Arbequina olive trees were added and monitored for symptoms. Preliminary analysis suggests that the olive pomace in its raw state contains compounds that inhibit germination and growth and may have benefit in olive production as a soil amendment in fields with known V. dahliae pressure.