Thermotherapy of Olive Trees Infected by Fusarium causing of Root Rot of Using Heat Treatments in Southern Tunisia

Background: Recently disease incidence of rot root caused by Fusarium (solani and oxysporum) is the new disease affecting the olive in Tunisia. Therefore Integration of biological control measures to protect olive planting material produced by nurseries could help managing Fusarium wilt in olive.  Materials and Methods: This study describes techniques to control the pathogen. Disinfect plants is critical in the nursery industry. The effects of several combinations of exposure time to temperature were evaluated: the survival of pathogens on a culture medium (PDA), the viability of the pathogen on infected shoots and plants, vegetative growth of plants of several cultivars, and the ability to root cuttings. Results: Colonies of the pathogen increasingly on PDA medium were killed after 7 h and 60 min exposure at 40 and 47 ° C, respectively. Temperatures <44 ° C for at least 2 h were lethal to the pathogen infecting the shoots. Similarly, hot air treatments humid at 44-46 ° C for 6-12 h eradicated the pathogen without compromising the viability of the plants. Five olive cultivars from south of Tunisia were also evaluated and classified according to their thermotolerance as follows: sensitive Chemlali Djerba, moderately sensitive Koroneiki, and heat tolerant Chetoui. However, optimized sanitation processes are applicable to all cultivars. Finally: heat treatments were applied to rooted cuttings, which severely affected their rooting ability. Conclusion: Thus, this study developed a hot air treatment to produce free olive nursery plants. Biological control of plant diseases has received worldwide attention in recent years.