EFFECT OF RUST ON YIELD OF SUSCEPTIBLE AND RESISTANT ASPARAGUS CULTIVARS

The effect of rust, caused by Puccinia asparagi, on yield of two slow-rusting and two rust-susceptible cultivars of asparagus (Asparagus officinalis) was determined in two consecutive years in the field. Rust was or was not controlled with a fungicide. Rust reduced total weight and number of spears produced by the susceptible cultivars but not by the resistant cultivars. Weight per spear was reduced only after the second consecutive year of rust infection in the susceptible cultivar Mary Washington. The second year of infection reduced relative yields more than the first year for the susceptible cultivars.