First report of Fusarium temperatum in diseased sweet corn ears in the Western United States.
Sweetcorn (Zea mays convar. saccharata var. rugosa) is subject to a number of Fusarium ear and stalk rot pathogens. Fusarium temperatum, a species described recently, has been identified in Z. mays in Europe, South Africa, and Central America, and more recently, in China and Argentina. It was first reported as causing disease in Z. mays in North America in Iowa, USA. In August 2015, several isolates of Fusarium spp. were taken from samples of diseased, market-fresh sweetcorn kernels harvested in the Treasure Valley region of southwestern Idaho, USA. Symptoms of developing ear rot infection included pinkish hyphae among the kernels and a few ruptured kernels throughout the ears. Based on morphological characteristics, sequence analysis of the elongation factor-1α gene and pathogenicity tests, the causal agent was identified as F. temperatum. This is thought to be the first report of F. temperatum from the western USA.