Figs are grown by numerous homeowners, particularly in the eastern part of the state. Generally, figs are relatively free of disease. In most instances when diseases occur, they are associated with soil-related problems or climatic conditions such as winter temperatures in the lower teens or colder or extended rainy periods in the summer when fruit are ripening.
Root knot caused by the root-knot nematode is the major disease affecting figs grown in sandy soil. Damage from this root-feeding nematode is progressive and results in poor growth, low vigor, yellowing and bronzing of foliage, low yield and poor fruit quality. To determine if root knot nematodes are causing the above ground symptoms, examine the roots for galls. Your local county extension agent can assist you in obtaining a diagnosis.
Currently there is no chemical registered for nematode control on established plants. If the root-knot nematode commonly occurs in the area, or if a soil assay indicates the nematode is present, some type of control procedure should be used prior to planting. The following may aid in reducing nematode problems:
- Choose a planting site in which a fig plant has not been previously grown, or where root-knot susceptible plants such as tomatoes, okra, or tobacco have not been recently grown.
- Complete fallowing of the planting site (approximately 4 ft x 4 ft area) during the summer and fall prior to planting can reduce nematode populations.
- If only one or a few fig bushes are being planted, removal of the existing soil and replacement with a high organic potting soil mix can be used. Remove the existing soil from a 3 to 4 ft diameter area to a depth of 18 to 24 inches then fill the hole with soil potting mix that can be obtained at most garden centers. High organic matter in the soil can reduce root-knot nematodes.
- Plant only nematode and disease-free plants.
None of these practices will totally prevent reestablishment of root-knot nematodes but should help the plant get off to a good start. Water and fertilize the plants to maintain adequate but not excessive vigor.
Blights, Stem Cankers, and Leaf Spots
Several fungi cause leaf and stem blights, stem cankers and leaf spots. These can result in the wilting and dying of stems, branches and leaves. Often the starting points for these diseases are areas on twigs and branches that have been injured or killed by cold injury. Prune out and dispose of all injured and dead twigs and branches. Rake up and dispose of all fallen leaves.
Anthracnose results in a soft rot and dropping of the fruit. The first symptoms appear as small sunken and discolored areas. The areas increase in size and pink masses of spores become visible. When immature fruit are infected, they may mummify and remain on the branches in a dried condition. Fallen and diseased fruit should be disposed. Dried and diseased fruit should be removed from the trees since these will harbor the fungus.
Premature Fruit Drop
Sometimes the fruit fail to mature. This may not be due to disease but rather to natural conditions such as the type of plant and the kind of flower it produces. Figs may bloom several times a year; the fruit that develops from early blossoms may be injured by spring frosts while the fruit from late blossoms may not have sufficient time to mature. Fruit may also drop from plants stressed by nematodes or environmental conditions such as dry weather.
Souring of Fruit
"Souring" results from spoilage due to fermentation by various yeasts, other fungi and bacteria. This condition is most severe during prolonged rainy periods. Pick figs regularly and do not allow them to become over ripe on the tree. If souring occurs, little can be done other than to remove and destroy all infected fruit.
Cold injury is often the limiting factor particularly in the piedmont and mountains. Cold injury can be severe enough to kill the plant or weaken it, making it more susceptible to twig and stem canker-causing fungi. Buds on injured branches shrivel and fail to leaf-out. To aid in reduction of cold injury, figs should be planted in a protected area and maintained in good vigor but avoid the use of excess nitrogen. Killed and injured branches should be pruned out in early spring.
Nutritional problems can cause low vigor, small fruit, and poor fruit production. Prior to planting, have a soil test done by the N.C. Department of Agriculture & Consumer Services to determine nutritional needs. Additional tests may be needed later if symptoms of low vigor or poor fruit production are observed. Your county agent can provide soil test information.
Note on Recommendations
Caution: The information and recommendations in these Notes were developed for North Carolina conditions and may not apply in other areas.
Recommendations of specific chemicals are based upon information on the manufacturer's label and performance in a limited number of trials. Because environmental conditions and methods of application by growers may vary widely, performance of the chemical will not always conform to the safety and pest control standards indicated by experimental data. All recommendations for pesticide use were legal at the time of publication, but the status of registration and use patterns are subject to change by actions of state and federal regulatory agencies.
Publication date: Dec. 17, 2013
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