Effect of organic media, alone or in combination with bio-products, on olive plantlets growth and Verticillium dahliae infection

Two organic media in comparison with the conventional medium, which were set up at MAIB, were tested alone or in combination with two commercial bioproducts. The media composition differentiates for the type and quantity of peat moss/compost and fertilizers. The micro and macro nutrients of the conventional medium were replaced in the two organic media by 1% (v/v) of a bio-fertilizer obtained from poultry manure. In the organic IAMB-ECOS medium, 30% of peat moss was replaced by a commercial certified compost. Trials with these media treated with a suspension of the bioproducts were carried out on grafted olive plantlets (‘Leccino’). Before transplanting, olive plantlets were inoculated by dipping roots in a conidial suspension of Verticillium dahlia. Uninoculated plantlets were used as a control. The effects of the different media, alone or in combination with bioproducts, on vegetative parameters of olive plantlets (plant height and root weight) as well as on V. dahlia infection were evaluated. Olive plantlets grown in Verticillium free media showed a significant increase in all vegetative parameters. Mainly in the organic IAMB media. Moreover, plantlets growing in the organic IAMB-ECOS, in combination with the commercial bioproducts, showed the best vegetative parameters, as well as a significant reduction of V. dahlia infection.