Tropical ornamentals, such as the Bird-of-Paradise, Variegated Pineapple, Hibiscus, Polynesian Princess and assorted palms, create a striking presence in the garden and home. In addition to requiring specialized growing conditions and care, tropical ornamentals have their own set of diseases with which to contend. Proper maintenance and early detection of tropical diseases is critical in maintaining the beauty and vitality of these special plants.
Bacterial wilt infects the vascular system of a plant, where the bacteria multiplies and cuts off the plant's ability to absorb moisture. Once a plant has been infected, there is no way to eliminate the disease. Insects that feed on infected plants then carry the disease to new locations. The only way to prevent bacterial wilt is to control pest infestations with insecticides.
Root rot, brought on by phytophthora mold spores and excessive moisture around the root system, causes the root system to suffocate. As the roots die off, the rest of the plant will not be able to absorb moisture and nutrients, and eventually will succumb to the disease. Healthy portions of the infected plant may be propagated; however the diseased plant should then be removed and destroyed. Root rot can be prevented by keeping the soil evenly moist and not allowing water to stand around or build up in the soil that supports the plant.
Leaf spot is caused by excessive moisture and heat and transported from plant to plant by wind, rain, and even sprinkler systems. Once a plant is infected, brown and black spots with yellow rims will form on the foliage. Copper-based fungicides can help to prevent the spread of the disease, but will not eliminate it completely. Remove all diseased leaves and stems, mulch around plant bases, and disinfect gardening equipment to prevent further spread of leaf spot.
Annual and perennial cankers, caused by assorted fungi and bacteria, invade plants through damage to wood and bark. As the disease progresses through the plant, it causes decay and growth of tumor-like formations that girdle branches and wood. Diseases portions of the plant can be removed, depending on the location of the canker, and should be destroyed. Cankers can be caused by overcrowding, overwatering and insect infestation.
Rots of Palm
Pathogens such as Thielaviopsis paradoxa and Phytophthora palmivora, attack palm plants and trees with a disease known as Rots of Palm. No matter which strain attacks the plant, the bud is killed, and the spear and new leaves of the palm will begin to discolor and wilt. Use of copper-based pesticides can prevent attacks, which are typically caused by damage from cold temperatures.