I have two young mango plants suffering for three years from anthroanose disease. I have used neem oil,daconil,fungicide 3 in one Fungicide,insecticide, miticide nothing seems to be helping what else can i do? Its a julie and east indian mango.I live in central florida.
Focus on soil and water management. Trees with nutritional deficiencies and water deficit or excess will be more vulnerable to pest and disease issues.
The best is a soil test and prescription mineral and biological amendments. But a general purpose, natural/organic, slow release fertilizer is next best.
If you use 70% Neem Oil (clarified hydrophobic extract of neem oil), its a fungicide, miticide and insect pest repellent. But a one time application will not be effective for more than two weeks or so. You need to repeat the application every two weeks during the growing season.