Solution You can prevent the transplant shock by carefully moving the tree to the ground. Airflow around the roots is reduced, so they cannot absorb moisture or oxygen. Giving them too much water, especially mature Mango trees, may experience their leaves to become yellow. You need to move to control and protect your tree when that problem occurs. And use a fungicide if the fungal problem persists. Most leaves are either gone or wilting. Solution The disease can be controlled by regular field spray programs, including copper-based fungicides. Once its planted, there are many reasons why a mango tree may be dropping leaves. Still no improvement. Water the plant only once the soil dries up to avoid the growth of fungi on the roots. The mango flowers can be clipped until the weather stabilizes and conducive for the fruits to form. If you notice water sitting in the soil or feel that the soil is overly moist by the touch of your fingers, transplant your mango plant into new soil with well-drainage.