Distribution and Pathogenic Characterization of Pyrenophora tritici-repentis and Stagonospora nodorum in Ohio.

ABSTRACT To determine the distribution of Stagonospora nodorum and Pyrenophora tritici-repentis on wheat in Ohio, flag leaves with lesions were collected from wheat-producing counties in 2002 and 2003. Counties were arbitrarily grouped into seven regions. Log-linear analysis of pathogen presence within regions indicated that the presence of S.

Reaction of Commercial Soft Red Winter Wheat Cultivars to Stagonospora nodorum in the Greenhouse and Field.

Thirteen cultivars were evaluated in the greenhouse and field for reaction to Stagonospora nodorum leaf and glume blotch. Coker 9663 exhibited consistent resistance across both greenhouse and field tests. In field plots, all cultivars tested had relatively high percentages of S.

Effects of Choline, Betaine, and Wheat Floral Extracts on Growth of Fusarium graminearum.

Fusarium head blight has been more severe when infection occurs during anthesis, indicating that floral organs may be important infection courts. Choline acetate and glycinebetaine have been extracted from wheat and reported to be growth stimulants of Fusarium graminearum. They are hypothesized to enhance infection and tissue colonization.

Evaluation of Inoculation Methods to Determine Resistance Reactions of Wheat to Fusarium graminearum.

Reliable greenhouse assays are needed to differentiate types of resistance in wheat to Fusarium graminearum. Genotypes with known field reactions were evaluated for resistance type using four greenhouse inoculation techniques. Percentage of spikelets with symptoms per spike (severity) and percentage of inoculated spikelets per spike developing symptoms were assessed 7, 10, and 14 days after inoculation (DAI).