"Rhizopus microsporus" is similarly one of three common "Rhizopus" species to cause the disease "Rhizopus" Head Rot in confectionery sunflower species. Alongside "R. oryzae, R. microsporus" causes the premier head rot of sunflower in South Africa. Susceptibility to disease changes throughout the age of the host. Heads inoculated at the budding stage simply do not become infected. However, when inoculated at the anthesis stage, loss was relatively high. Yield was not reduced significantly when heads were inoculated at the seed development stage.