Fungal diseases and biological control possibilities in the lavender fields of the turkish lakes region

In this thesis, fungal diseases and biological control options were investigated in the Lakes District of Turkey, which produces the highest amount of lavender (%42: Isparta, Denizli, Afyonkarahisar, Burdur). Various pathogens threatening production, including Fusarium, Epicoccum, and Rhizoctonia species, were identified using morphological and molecular methods. In pot experiments with the susceptible Lavandula angustifolia 'Sevtopolis' variety, the combined effects of the antagonist fungus Trichoderma harzianum and the mycorrhizal fungus Rhizophagus intraradices from our collection were compared with commercial preparations T-22 Planter Box and Shubhodaya against the highly virulent pathogens Rhizoctonia solani (80%) and Fusarium oxysporum (73.3%). In growth parameters, the synergistic effect of the collection Trichoderma (Kt) + collection mycorrhiza (Km) application was prominent, while the commercial mycorrhiza (Tm) + commercial Trichoderma (Tt) application was the most effective in reducing disease severity. Among the induced resistance mechanisms in plants, the highest increase in total phenolic content was observed with the Km application. Levels of important phenolic compounds analyzed by HPLC showed differences across treatments. Km was the most effective in increasing the levels of p-coumaric and rosmarinic acids. Aromatic compounds in lavender were analyzed by GC-MS SPME. In the presence of F. oxysporum, treatments increased the production of defense compounds such as camphor, 1,8-cineole, and borneol, while fluctuations were observed in their amounts in the presence of R. solani, with reductions in linalyl acetate and linalool levels.