Citrus trees are flowering plants that are part of the Rutaceae (rue) family. They are popular landscape trees that are notable for their edible fruits (such as lemons, limes, oranges and grapefruits) and scented blossoms. Citrus trees are native to subtropical and tropical areas. As with most plants, there are some problems that are sometimes associated with citrus trees, such as pests and diseases.
Greasy spot is the name of a common fungal infection that citrus trees experience. Some warning signs of greasy spot include brownish-yellow blisters appearing on the tree's foliage, generally on the undersides of the leaves. As greasy spot progresses, the blisters become oilier in appearance. This disease often results in severe loss of leaves, especially during the winter. It can also lead to citrus infestation, especially for grapefruits. Greasy spot can be managed by regular and frequent collection and elimination of fallen leaves, which decreases the development of new spores. Fungicides can also be used.
Citrus whitefly is a common pest that can be problematic for citrus trees. Citrus whiteflies are winged, small insects that are approximately 1/2 inch long. They often appear feeding on citrus trees' foliage undersides. When the branches of the tree are shaken, the whiteflies will quickly fly away and tend to appear fluttering surrounding it. The insects also lay their eggs on the foliage's undersides. Upon the hatching of the eggs, tiny, oval and clear larvae connects to the undersides of the leaves and sucks its sap, which results in the curling of the leaves. The leaves also become covered in a sooty, mold and sticky covering. These pests can be managed by spraying insecticide on the citrus trees.
Melanose is a fungal disease that affects citrus trees. Melanose is an infection that generally affects younger citrus fruit. It most commonly affects grapefruit, but can also affect lemon, limes and oranges. The disease is characterized by the fruit rind developing an unpleasant scabbed appearance. However, it does not change the quality of the fruit. With citrus trees that are more than 10 years in age, melanose tends to be more severe. Prompt and frequent pruning is an effective way to prevent and control the disease. Fungicides also can be used.
Citrus Bud Mites
Citrus bud mites are pests that frequently attack lemon trees. They are especially prevalent in coastal regions. Citrus bud mites are elongated and tiny insects that have four legs at the front. Their posteriors are tapered. Citrus bud mites tend to attack trees during the summer. The pests are often difficult to detect. However, massive infestations can usually be spotted by looking closely at the bottoms of the fruit. The insects feed within the buds, either destroying them or resulting in a growth that appears similar to rosettes. The fruits and flowers of the trees also can be distorted due to these pests. Insecticides can be used to treat these mites.