Citrus Canker: This fast-spreading bacterial infection unfortunately is quite common and can mean the end of many dwarf fruit trees. This contagious infection often appears as yellow or orangish colored lesions on the fruit, leaves and small branches of the tree and is spread through infected insects, birds and even gardening tools. One of the most effective ways to prevent citrus canker is to spray your tree with a liquid copper fungicide and by staying aware of any reports of the disease in the area.

Melanose: This disease though not serious or life threatening for most tree species can affect the appearance of the fruit produced and can lead to marked or scabbed fruit rind. Melanose is most commonly found in older trees which have been planted for more than ten years. It is also quite common, but not exclusive to dwarf grapefruit trees. The best treatment available is an anti-fungal spray.

Greasy Spot: This disease is probably the most common for dwarf fruit trees and can lead to dramatic leaf loss and branch weakening. The easiest way to see if your tree is suffering from Greasy Spot is to check the underside of the leaves for brownish-yellow blisters. To prevent the spread of greasy spot simply remove all of the fallen leaves quickly and use a liquid copper spray twice a year, once in the midsummer months and another in the early fall.

Here is a quick reference guide to some of the most common citrus tree pests:

Aphids: Though it is next to impossible to not have any aphids present while growing trees, they can grow in numbers rapidly and can do a lot of damage in a short amount of time. The marks left by aphids are often confused with other citrus diseases because of the dark marks which appear on the leaves. Aphids can damage a tree’s growth by sucking the sap from their leaves and causing leaves to drop and dry.

Citrus White fly: A common pest to appear on all types of citrus trees, Whiteflies are a winged insect close in size to a common fruit fly. Whiteflies will often hide on the underside of a tree’s leaves and suck the honeydew sap from the leaves veins. Similar to aphids the damage left by whiteflies is often confused with leaf rot and is similar in appearance to mould.

Orange-dog caterpillars: A large insect, orange-dog caterpillars will eat and rip the edges of a trees leaves. Though this type of caterpillar is most common in Florida it can be found on plants which have been imported and sold in other regions. The best way to rid your tree of orange-dog caterpillars is to remove them by hand. But be warned, when disturbed this species will spring two red “horns” from its head and spray a foil smelling odor.

Citrus Thrips: One of the most damaging of all citrus diseases and pests, the citrus thrip will ruin a young tree’s leaves, fruit, blossoms and roots. These persistent pests are yellow and orange in color and can usually be found on the underside of the tree’s lower leaves. The marks left by citrus thrips will be quite evident as most of the fruit, blossoms and leaves which are attacked will shrivel up and dry out completely.

Citrus Bud mite: Though bud mites can attack any type of citrus tree, they are most commonly found on lemon trees. Bud mites will appear only in hot and humid climates and will enjoy feeding on the lemon blossoms and fruit buds. To rid your plant of bud mites consider using the same all natural sprays that you would to eliminate any citrus diseases.

Knowing how to recognize fruit problems is not easy and it can take quite a bit of time to familiarize yourself with the signs, warnings and characteristics of each type of fruit-related ailment. However, not all citrus tree fruit problems are common in North American regions.

The two most common types of fruit diseases are referred to as fruit drop and citrus scab. Here is a brief description of each:

Fruit Drop: The signs of severe fruit drop are quite obvious. Early in the fruit formation period, small immature fruit will fall from the tree in large quantities. Though it is normal for a fruit tree to drop some of its fruit as a self-thinning process, an abundance of fallen fruit is a much more serious issue. Fruit drop is most commonly caused by stress, late frost, lack of water, too much water or even inadequate fertilization.

To avoid Fruit Drop consider fertilizing your tree annually in the spring growing season. It is also imperative to use a fertilizer which is specifically designed with the needs and requirements of citrus trees in mind.

Citrus Scab: This fruit infection is common, and can lead to wasted fruit as well as premature leaf drop. Citrus scab can be identified by the accumulation of small brown raised marks on the skin of maturing fruit. Citrus scab may also result in brown, dried areas on leaves and delayed growth and development.

Citrus Scab and other similar citrus tree fruit problems are caused by overly-damp conditions and excessive watering during wetter seasons which lead to a build up of aggressive fungus. Controlling citrus scab is not difficult for the most part and all that is needed is a fungicide spray or treatment.

It is also recommended that you refrain from watering your citrus tree with a sprinkler, as a drip hose near the base of the tree is much more effective and will prevent the spread of citrus scab and other citrus tree fruit problems.