Elderberry Rust: A Conspicuous Disease of Sambucus

Interest in growing elderberry has surged in the past few years due to the potential for high economic returns for producers and increased consumer interest in health-promoting food products. As commercial growers expand their acreage and plantings mature, production problems have been identified, including elderberry rust. This disease is caused by the fungus, Puccinia bolleyana.  Elderberry rust requires two living hosts to complete its life cycle, including elderberry and a sedge (Carex) species.  Although elderberry rust symptoms have been described, plant response to this disease has not been reported. Thus, a study was conducted to determine the effect of rust on vegetative growth, fruit yield, and berry puree of American elderberry plants inoculated on 22 April.  By 17 June, pycnia were observed 34% of elderberry leaves per plant. Preliminary results indicate that fruit harvest was delayed on rust-infected plants.  Inoculated plants also had lower fruit yield and average berry weight than uninfected plants. Soluble solids were higher in fruit puree from rust-infected plants than from uninfected ones.