The levels of resistance to stripe rust (Puccinia striiforrmsf. sp.tritici) in the leaf and in the spike were related in most wheat (Triticum aestivumL.) cultivars. Cultivars with seedling resistance to stripe rust were not infected in the spike. However, two cultivars, Otane and Advantage, with adult plant resistance on the flag leaf, were infected in the spike. In a susceptible cultivar, Takahe, infection of florets occurred from ear emergence until flowering. In susceptible cultivars, pustule formation began at flowering, approximately two weeks after infection, with the maximum percentage of florets with pustules occurring during milk development. A single application of triadimefon to heavily infected ‘Takahe’ wheat at full ear emergence reduced floret infection from 75% to 20% and increased crop yield by 34%.