New citrus trees are particularly susceptible to disease because they have not developed to the point where they can fend off infections without serious risk to the health of the entire tree. Knowing what to look for and how to prevent problems with your new citrus tree can be helpful when raising it to maturity.
You want to make sure your tree is getting plenty of water, but resist the temptation to water every day or in the afternoon. Too much water and water too late in the day lead to fungal infections in the roots, also called root rot. While a mature tree may manage to simply extend its roots deeper, new citrus trees need regular watering and may not be able to outlast a fungal infection. Watching your watering habits will help.
There are a variety of infestations that may attack your new citrus tree. Aphids, mites and whiteflies can all lay their eggs and leave them to wreak havoc on your new tree. All of these insects can be found on the underside of the leaves. The best way to deal with them is to pre-treat your tree before flowers and fruit appear (if your tree is mature enough), using a pesticide to prevent the infection entirely.
Cankers and Mold
Young citrus trees are not just susceptible to mold below the ground, they are also susceptible to bacterial and fungal infections above ground. Cankers are bacterial infections that appear in the form of dark knots on the bark of the tree, while mold can grow anywhere on the tree's limbs, leaves, flowers or fruit in the form of black, gray or white powdery film. Monitor your tree for these symptoms, and if you spot them, you need to use sterilized pruning methods to remove the infected areas.