Start Date: May 06, 2009
End Date: May 05, 2014
Project Title 1: Inoculated, mist-irrigated field experiments examining FHB development and DON accumulation will be established at the Minnesota Agricultural Experiment Station in St Paul, MN and the Cunningham Research Station in Kinston, NC. Two field experiments will be conducted. The first, which will be planted in NC and MN, will examine the effects of post-anthesis moisture and late infections on DON accumulation in winter and spring wheat cultivars, respectively. The goals of this experiment are to confirm previous findings on the influence of host resistance, pathogen aggressiveness and moisture duration on the development of FHB and accumulation of DON in wheat; to illuminate the influence of host-pathogen genotype interactions on fungal colonization and DON production in different tissues; and to detect differences in the relative ranking of cultivars under different infection-timing-by-mist-duration treatments. The second experiment, to be planted in NC, will investigate the cultural implications of our findings on DON development during the grain-fill period under different durations of post-anthesis moisture. Main plots in this experiment will be 0 and 21 days of post-anthesis misting, and sub-plots will be different durations of moisture during the harvest period. The purpose of this experiment is to explore our previous finding that grain DON decreases near normal harvest time, and to determine how the trend is affected by different numbers of moist days during a potential harvest-delay period. In addition, greenhouse experiments will be conducted in MN. These experiments are designed to confirm the effect of moisture (using wetting events applied between 7 and 28 days after inoculation) on the development of FHB symptoms and the accumulation of DON in wheat floret tissues. The impact of wetting events applied both before and after the full expression of symptoms will be determined. Project Title 2: The proposed nursery will be located in Rosemount Minnesota and will be inoculated with F. graminearum macroconidia and mist-irrigated. This research is needed because increasing the efficiency of individual breeding programs to develop FHB resistant varieties and developing effective FHB resistance through transgenics are major strategies of the USWBSI for reducing the impact of FHB in wheat and barley.