Studying behaviors of four Italian lemon rootstocks towards Mal Secco leaf infection with the fungus Phoma tracheiphila, isolated in Tunisia in controlled environment, is the aim of this research work. It involves prospection of infected lemons fields in Tunisia, isolation and morphological identification of the fungus, preparation of inoculum and infection of leaves of four rootstocks. Following the artificial inoculation in three assessments after 10, 20 and 30 days post inoculation (dpi) by observing the appearance of disease symptoms, counting the percentage of positive inoculation and determining the average disease intensity according to the leaf empirical scale. All these parameters indicated about the behaviour of the rootstock towards disease in addition to allowing the classification of the four lemon rootstocks according to susceptibility to Mal Secco. PrimeOA Publications International is one of the leading Open Access Publishers which is publishing 700+ peer-reviewed journals with the support of 50,000+ editorial board members as editorial team and aimed to disseminate the scholarly knowledge to the scientific society. PrimeOA Publications also organizing 3000+ International Scientific Conferences and events yearly all over the world with the support of 1000+ Scientific associations worldwide. Citation: Ziadi S, Chebil S, Ligorio A, Ippolito A, Mliki A (2012) Behavior of Italian Lemon Rootstocks towards Mal Secco Leaf Infection with Tunisian Fungus Phoma tracheiphila in Controlled Environment. J Plant Pathol Microb 3:150.