Oil palm trees grow throughout the world's tropical regions. They yield a high ratio per tree of oil and therefore present a lucrative agricultural venture for the many large and small growers in the palm oil industry. Palm oil is in demand the world over as an ingredient in products such as cooking oil and shortening. One difficulty that palm growers frequently encounter is the incidence of debilitating or fatal oil palm diseases.
Crown disease in oil palm trees is not usually fatal to the plant and often runs its course by the time the tree has reached its fourth year. Symptoms of crown disease are concentrated in the tree's leaves. Opening palm spears appear bent, and established fronds are plagued with fungal rot. The various causes of crown disease include early stresses to the plant during initial root formation, poor nutrition and genetics. While most trees recover from crown disease, the illness compromises their oil yield up to 5 percent during the first year.
Ganoderma Butt Rot
This lethal palm disease is caused by the Ganoderma fungus and is also known as white rot and basal stem rot. The disease begins within the base of the tree, where the fungus kills the inner stem tissue as far upward as five feet or so. As the Ganoderma progresses towards the outer tissue of the tree, it makes itself known with the appearance of fungal conks--shelf-like protrusions on the outside of the trunk. These conks--or basiodiocarps--release spores into the air, which could infect other oil palms in the area. Although the basal rot occurs in the lower five feet of the trunk, the leaves of infected oil palms show symptoms. They may wilt, become lighter green in color and emerge stunted.
Red Ring Disease
While not yet observed in U.S. oil palm plantations, red ring nematode--a parasitic worm--threatens oil palms in South America, Central America, Africa and the Caribbean Islands. A deadly disease, external signs of red ring invasion are not apparent until a couple of months after infection. Internally, a crosscut of an infected palm will reveal a distinctive red to dark brown circle within the inner tissue of the tree. The red ring nematodes enter the tree on the back of palm weevils that work their way into the trunk via cracks or wounds to lay their eggs. Infected trees often grow deformed leaves, which eventually give the crown an uncharacteristic funnel shape. Young trees can die from red ring disease in as little as six to eight weeks.