Mosaic viral symptoms on fig have shown up during the heat of summer in Oregon. The likely culprit is fig mosaic virus, actually a complex of different viruses which can infect Ficus spp. The disease was first reported on the west coast in California in the 1930's and is now found in most areas where figs are grown. Fruit from some varieties of infected figs may be smaller, misshapen, and less abundant.
Do not propagate from plants showing mosaic symptoms as the virus can be transmitted by vegetative propagation. If possible, obtain stock material from a virus-free source.
Useful links:
UC IPM Online: Fig mosaic virus
Burnet, H. 1960. Species of Ficus Susceptible to the Fig Mosaic Virus. Florida State Horticultural Society Proceedings
Falk, B. and Salem, N. 2006. Fig Mosaic.
Page last modified 9/4/09