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.