Abstract

The main objective of the chemical disease control in modern agriculture consists of diminishing the use of contaminant pesticides employing stimulant components of the natural plant defense mechanisms. In the present work, in a preliminary form, the effect of soil chitosan application and chitosan hydrolyzate by foliar spraying (individually and combined treatments) was evaluated on the induced protection against the attack of Fusarium oxysporum fsp licopersicii in susceptible tomato varieties. Doses of 250 ppm were employed by treatment, which results in a low development of diseases in comparison with the control. Moreover, several mechanisms of plant defense related to the biological effect analyzed were studied. The best results of protection were observed by the combined application of elicitors, with the high values of β 1,3 glucanase activity like a defense response against the attack of soil fungal pathogens.