Progression of Fusarium Head Blight Caused by <i>Fusarium graminearum </i>Schwabe Epidemic and Grain Yield of Wheat ( <i>Triticum aestivum</i> L.) as Affected by Host Resistance and Seed-Treating Fungicides in Southern Ethiopia

Abstract

Fusarium head blight (Fusarium graminearum Schwabe), FHB, is considered as one of the economically important and destructive diseases of wheat. Thus, the field experiment was carried out at seven locations in Southern Ethiopia during the 2019 main production season to determine the effects of host resistance and seed treating fungicides on the progression of FHB epidemics and to determine grain yield benefit and yield losses derived from the use of a combination of wheat cultivars and seed treating fungicides. The study was conducted with a combination of two wheat cultivars (Shorima and Hidase) and five seed-treating fungicides, including Carboxin, Dynamic, Imidalm, Proseed Plus, and Thiram Granuflo. A total of 12 treatment combinations were formed, including an untreated. The experiment was laid out in a randomized complete block design in a factorial arrangement with three replications. The results obtained showed that North Ari exhibited the highest disease incidence (100%), severity (83.38%) and area under disease progress (AUDPC) (807.74%-day), and the lowest grain yield (0.94 t ha-1) than the other locations. Lowest incidence (10.93 and 13.52%), severity (10.96 and 12.26%), and AUDPC (59.81 and 71.74%-day), and the maximum grain yield (5.76 and 5.59 t ha-1) was recorded at Bonke and Chencha, respectively. Lowest incidence was registered on Shorima in combination with Dynamic fungicide (27.40%). Minimum disease severity was recorded on Shorima cultivar in combination with Imidalm (21.23%) and Dynamic (21.78%). The AUDPC was as low as 211.27, 226.39, and 236.46%-day in combination with Shorima with Imidalm, Dynamic, and Proceed Plus, respectively. The highest disease severity of 57.91 and 27.22%, and AUDPC of 552.71 and 313.04%-day were recorded on unsprayed plots of Hidase and Shorima cultivars, respectively. Based on the lowest yield loss and economic feasibility advantage, the use of Shorima in combination with Imidalm and Dynamic seed treating fungicides independently could be recommended to the farmers in the areas and similar agro-ecologies to manage FHB. However, the lonely use of seed treating fungicide does not as effective as post-anthesis aerial application of fungicide up to maturity of the crop; post-anthesis aerial application of fungicide should be considered in addition to seed treating fungicide for effective management of FHB.