What is Rio Grande Gummosis?
Citrus Rio Grande gummosis is a fungal disease caused in part by the pathogen Diplodia natalensis along with several other fungi. What are the symptoms of Rio Grande gummosis of citrus? As mentioned, citrus trees with Rio Grande gummosis form blisters on the bark of trunks and branches. These blisters ooze a sticky gum. As the disease progresses, the wood beneath the bark turns a pinkish/orange color as gum pockets form under the bark. Once the sapwood is exposed, decay sets in. In the latest stages of the disease, heart rot may occur as well.
Rio Grande Gummosis Info
The name citrus Grande Rio gummosis comes from the area where it was first observed, the Rio Grande Valley of Texas, in the late 1940s on mature grapefruit trees. The disease is also sometimes referred to as Florida gummosis or ferment gum disease. This gumming disease of citrus has been found to be chronic in nature. It is most often observed in mature trees of 20 years or older but has also been found to afflict trees as young as 6 years of age. Weakened and/or injured trees seem to have a higher incidence for infection. Factors such as freeze damage, lack of drainage, and salt accumulation within the soil also foster the incidence of the disease. Unfortunately, there is no control for citrus Rio Grande gummosis. Keeping trees healthy and vigorous by practicing excellent cultural controls is the only method for management of this disease. Be sure to prune out any branches damaged by freezing and encourage speedy healing of the injured limbs.
