sentences:  Long term cultivation may affect disease resistance, and very little breeding for resistant varieties has been undertaken; due to this, almost all cultivars show susceptibility to "O. mangiferae" and it is extremely widespread.The most popular variety of mango, the Tommy Atkins, was developed in the 1920s in Florida and is favored because of its long shelf life and anthracnose resistance, though it is still somewhat susceptible to powdery mildew and control strategies must still be enacted.Diseases of perennial crops such as mango are devastating due to the long time period to maturity for the plants, as a tree grown from seed will not produce fruit until it has reached three to six years of age.