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Poster: Diseases of Plants: Disease Detection & Diagnosis


Effect of leaf spot pathogens and fungicide application on Bacterial leaf streak development in wheat under field conditions in South Dakota
S. ALI (1), S. Sehgal (1), K. Glover (1), N. Kaur (1) (1) South Dakota State University, Brookings, SD, U.S.A.

Bacterial leaf streak (BLS), caused by Xanthomonas compastris (Xc) pv. Undulosa, is an important disease of wheat in South Dakota. The objective of this study was to see the effect of fungal leaf spot pathogen “Pyrenophora tritici-repentis (Ptr)” (tan spot) and fungicide application on BLS development. To obtain our objectives, two wheat cultivars Briggs (BLS susceptible) and Select (moderately resistant) were planted in a randomized complete block design with three replications at SDSU Volga Agricultural Experimental Station, Volga, SD in 2014. Three plots of each cultivar was inoculated with; Xc cell suspension alone (T1), Ptr spores suspension and then with Xc (T2), Ptr, Xc and then applied fungicide “Prosaro” (T3) and Ptr alone (T4), and non-inoculated and untreated (T5). BLS disease data was recorded 12 days post-treatments. BLS disease severity was observed higher in T2 (50.5%) as compared to T1 (Briggs =23.33%) and T3 (41.83%) in both cultivars though the severity level was higher in Briggs as compared to Select. Our results indicate that Ptr infection may help in enhancing bacterial penetration. Also, fungicide application stops tan spot development and that may helps in increasing BLS development.