|Pests and Diseases of Figs:
Root-knot nematodes, Meloidogyne sp., are microscopic, soil inhabiting worms which attack the plant's root system. They attack and feed on roots, causing them to swell or gall; thus, interfering with normal uptake of water and nutrients. These galls are easily seen if root samples are observed. Nematode problems may go unnoticed for several years. As a heavy population builds up, the tree loses vigor and declines gradually. Nematodes contribute to premature fruit drop. To prevent rootknot nematodes in figs, obtain nematode-free plants and plant in nematode-free soil.
Mitadulid and Carpophilus dried fruit beetles can enter ripening fruit through the eye and cause damage by introducing fungi and rots. They frequently breed in fallen citrus fruits. Keep a clean orchard by destroying fallen fruits and do not grow near citrus trees. Euryphid mites cause little damage but are carriers of mosaic virus from infected to clean trees. Mosaic virus, formerly considered benign, probably causes crop reduction. Symptoms resemble potassium deficiency--leaves are marbled with yellow spots, and the veins are light colored. Symptoms are often not apparent until the tree is older or when it becomes heat or water-stressed. Do not purchase infected trees and isolate those which show symptoms.
Fig rust is an important fungus disease that attacks the leaves of figs. It is caused by Physopella fici. Fig rust first appears as small, yellowish-orange spots on the leaves. These enlarge slightly and may become very numerous as the season progresses. Rust causes complete defoliation of many trees in the state each year, resulting in ragged-looking trees. In addition, trees defoliated early in the season may initiate new growth which is often susceptible to cold injury. Defoliation usually does not occur early enough to cause fruit loss except in late ripening varieties. Rust is controlled with neutral copper sprays (see image). One or two applications made in May or early June usually keep trees in fairly good condition until after fruit ripens. In very wet seasons one or two additional applications may be necessary. A good index for spraying is when the first leaves on the tree have reached full size. The second spray should follow in 3 to 4 weeks. It is extremely important to get good leaf coverage with the spray material.
Botrytis causes a blast of branch terminals, which dry out and turn charcoal-like. The attack usually starts from half-grown fruits damaged by the first frost of winter, then enters the main stem as a reddish expanding necrotic zone. The infection is generally self-controlling and stops in the spring. It can be prevented by removing mummies and frost damaged fruits as soon as they are observed.
Fig canker is a bacterium which enters the trunk at damaged zones, causing necrosis and girdling and loss of branches. It usually starts at sunburned areas, so it is important to keep exposed branches whitewashed.
Rhyzopus smut attacks ripened fruits on the tree, causing charcoal black coating inside the fruit, and is worst on cultivars with large, open eyes. Most ripe fruit losses are from Endosepsis (Fusarium) and Aspergillus rot which is introduced by insects, even pollinating wasps. The fruit appears to burst, or a ropy, mucus-like exudate drains from the eye, rendering the fruit inedible. The best control is to destroy all crop for one year, apply diazinon granules beneath trees to eliminate insect vectors, and destroy adjacent wild trees.
Penicillium fungus will attack dried fruits in storage but can be controlled by keeping them dry, or sulfuring before storage.