Commercial & residential landscape design, large saguaro relocation specialists,
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Bacterial necrosis of saguaro cactus ( Carnegiea gigantea ) in ArizonaBacterial necrosis of saguaro is caused by the bacterium Erwinia cacticida. The initial symptom is a small, light colored spot with a water soaked margin on the surface of the trunk or branches. The tissue under the infection site soon becomes brown or almost black. As disease progresses, the tissue may crack and a dark brown liquid exudes. If decay is slow, the tissue may not have the liquid exudate, but the dead tissue will rot and may break into a mass that falls out, leaving the woody skeleton exposed. The pathogen, E. cacticida, survives in soil or plant tissue for long periods of time. Bacteria are spread by insects and in soil. Infections take place at wound sites on roots, trunks and branches such as those made by insects, rodents or weather related events, including freeze damage. Dead and dying plants serve as reservoirs of the bacterium and as sources of inoculum for new infections. In large natural stands where disease occurs, proximity of saguaros to infected plants has been shown to significantly influence mortality in nearby mature plants. However, disease is usually observed in older saguaros only. Young saguaros seem to be unaffected. New infection sites may be treatable when lesions are very small, less than 2-3 inches in diameter. Carefully remove the infected tissue, along with a margin of healthy tissue, using a clean sharp knife. Bathe the wound site with 10% bleach solution, and allow it to heal on its own. Older, and/or larger infection sites, especially those exuding dark liquid, are not treatable. If possible, diseased plants should be removed to prevent infection of nearby saguaros and damage or injury of persons or property We opted to remove and selected Shawn Widger of Arbor Tree and Cactus. As you can see they were quite talented and experienced in removing these behemoths. |
