Alternative control strategies are increasingly encouraged to develop sustainable crop protection. In this aim, we assessed the ability of Dalgin Active ® , an Ascophyllum nodosum extract-based product, to induce resistance in bread wheat and durum wheat against Zymoseptoria tritici, a major fungal pathogen on these crops. Foliar application of the product provided a strong and significant reduction of disease intensity on both wheat species without any direct effect against the pathogen. Infection process monitoring revealed that Dalgin Active ® did not prevent fungal epiphytic growth and leaf colonization, but its application results in an inhibition of sporulation as well as fungal cell wall-degrading enzyme and protease activities. During the early stages of infection, Dalgin Active ® activated several plant defense markers on both wheat species, including PR protein, antioxidant metabolism, phenylpropanoid, and octadecanoid-based pathways. Although few differences were recorded, the induced defense reaction patterns were overall similar in both wheat species, suggesting that Dalgin Active ® could be used to biocontrol Z. tritici on both crops.