Orange Tree Problems
Orange tree production is a major source of income for warm states like Florida, Texas and Arizona. Many farmers rely on orange groves for income and home gardeners delight in growing trees in their backyards. Unfortunately oranges can be plagued by a variety of pests, diseases and other problems. Most can be solved with proper and immediate treatment. Does this Spark an idea?
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Significance
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Pests, diseases and other problems with oranges, while often not drastic problems for home gardeners, can cause a host of problems for commercial production. Problems affecting oranges can cause damage to skins as well as fruit and decrease the market value of oranges. For small growers, infestations of pests and diseases can cause loss of income. Some pests and diseases can damage fruits rendering them inedible.
Diseases
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Many common diseases affecting the roots, fruit, branches and foliage of orange trees are caused by fungi. Greasy spot is a common fungal infection which appears as yellowish brown to black blister-like spots on the leaves and causes severe leaf loss. Gummosis of citrus is caused by parasites and appears as cracked, slimy, watersoaked bark beneath the soil. Sparse yellow foliage can be seen in more advanced cases, and orange trees may even collapse and die. Viruses in orange trees are often named for the problems they cause such as crinkly leaf and gummy bark. One of the most serious diseases is Tristeza which has caused serious problems in Florida and continues to in Brazil. Symptoms include yellowing leaves, decreased fruit size and pitting of the stem. A 1984 outbreak of citrus canker necessitated the burning of thousands of nursery plants in Florida to prevent its spread. This virus causes lesions on stems, fruits and leaves and can kill the tree. Blight is another major cause of orange tree loss, causing 500,000 orange tree deaths in Florida each year.
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Pests
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Rust mites are a common pest that afflict orange trees. They can cause blemished fruits and decreased fruit sizes. Citrus red mites and Texas citrus mites also create disfigured fruit and foliage. The worst scale insect enemy of the orange tree is the citrus snow scale, which infests the woody parts of the tree, sucks sap and causes the shedding of fruit and leaves. Mealybugs can be a problem for orange trees in spring and early summer. They form white masses under and between fruits and excrete honeydew which perpetuates the growth of sooty mold. The citrus blackfly, aphid and fruit fly also commonly afflict orange trees.
Mineral Deficiencies
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While often mistaken for disease, mineral deficiencies are a problem of their own. Iron, zinc and manganese deficiencies are quite common. Iron or manganese deficiencies are marked by a change in leaf color to a yellowish white with green veins. Mottled, yellowed leaves can suggest a zinc deficiency which can eventually cause smaller leaves and fallen leaves. Nitrogen deficiencies can be identified by greenish-yellow leaves that develop over a two- to four-year period.
Treatment
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Each orange tree problem needs highly specific treatment that is appropriate for the disease, pest or deficiency. In general, keeping orange trees healthy by sufficient watering and fertilizing can repel pests and disease. It is also important to take care of any problems with trees as soon as they occur. Some methods of treating orange tree problems are fungicides, pesticides and specialized fertilizers. Make sure to use a product that is safe for the orange tree and carefully follow the directions.
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References
Resources
- Photo Credit Orange tree image by Evgeny Berdjansky from Fotolia.com
