Fig trees (Ficus carica) are deciduous trees that prefer warm, dry climates, but they can also do well in colder regions with proper protection against the elements. These picturesque trees reach a height of 10 to 50 feet. Fig trees boast large green leaves, and their tiny flowers are clustered inside of the synconium, or the green “fruit.” Fig trees are susceptible to several diseases.
Fig rust is a fungal disease that causes defoliation by attacking the fig tree’s young leaves. The fig rust fungus (Physopella fici) first appears as light yellow-orange spots on the tree’s leaves. As the disease progresses, these spots enlarge and spread. Fig rust will eventually cause the leaves to drop off, making the tree look raggedy. The defoliation typically occurs late enough that it doesn’t cause any fruit loss. Leaf rust is most prevalent during the rainy seasons.
Fig trees are also susceptible to fig mosaic, a viral disease that causes large, yellowish spots to form on the leaves. These spots contrast sharply with the normal green foliage, creating a mottled effect. As the mosaic disease progresses, the spots become surrounded by a rust-colored ring, which is caused by the subepidermal or epidermal cells dying. Some fig tree varieties also develop mosaic lesions on the fruits. The fig mosaic virus also causes some tree species to suffer from premature fruit drop.
Anthracnose (Colletotrichum) is a common plant fungal disease that can attack all plant parts during any growth stage. Anthracnose symptoms tend to be most conspicuous on the fig tree’s leaves and ripe fruits. Anthracnose first appears on leaves as small black, yellow or brown spots. As the anthracnose disease progresses, these spots enlarge and merge to affect entire areas. This fig tree disease can also cause cankers to form on stems and petioles, resulting in severe defoliation and root rot. Infected fruit develop sunken, circular spots that might emit pink spores.
Root knot nematodes (Meloidogyne) are microscopic worms that live in soil and attack the fig tree’s root system. These nematodes feed on the roots, causing them to swell and reducing their ability to absorb nutrients and water. Because most of the damage takes place underground, the nematodes have the chance to do a lot of damage before being discovered. Infected trees suffer from premature fruit drop and a low fruit yield. Root knot nematodes commonly attack fig trees cultivated in sandy soil.
Proper fig care can help reduce the chances of fig trees contracting diseases. Fig trees should never be planted in areas where diseased fig trees previously grew. Any diseased tree should be removed and destroyed immediately. Diseased fruit must be removed from the trees because it harbors the fungus. Fig rust can be controlled by one or two applications of neutral copper sprays. Weeds need to be controlled and all plant debris plowed under after harvest.