Effects of infection with Ustilago nuda and of seed size on the vigour of barley plants

Abstract

Seeds of nine barley varieties inoculated with Ustilago nuda by the hypodermic needle method produced seedlings and plants less vigorous than uninfected or non-inoculated seeds. Seeds taken from different regions of the ear, although differing considerably in size, did not produce seedlings differing in vigour. Using a morphological marker, the type of hairiness of the rachilla, it was shown that there were no differential effects of increasing competition between seedlings from the smaller seeds obtained from the extremities of the ear and those from the larger seeds. It is concluded that smut infection has a greater influence on seedling vigour than has seed size.