Cover: Fusarium head blight of durum wheat (Triticum turgidum L. var. durum), caused by Fusarium graminearum Schwabe. On susceptible wheat, florets are infected at anthesis and within 2 to 3 wk (shown here) many spikes are entirely blighted; other spikes show partial blight--some spikelets are necrotic others are not. In this plot, some later heading spikes escaped the infection period (see Stack et al., 637-642). Photo by Jana M. Hansen.