2023/11/02 by Kebede, Metiku, Tsegaye, Yisahak
#AUDPC #Bread wheat #Grain yield #Severity #Stem rust
paper · doi:10.20372/star.v10i2.01
The stem rust disease caused by Puccinia graminis f. sp. tritici is the most striking among various wheat diseases that contribute to huge yield losses in Ethiopia. The effect of fungicide spray frequency on disease parameters and yield components of the bread wheat variety was studied under natural infection at Mareko and Dalocha during the 2020 growing season. Two different fungicides, Nativo SC 300 (Trifloxystrobin 100 g/l + Tebuconazole 200 g/l) at 0.75 l/ha and Tilt® 250EC (propiconazole) at 0.5 l/ha, were field evaluated with three spraying frequencies in a randomised complete block design with three replications. Unsprayed controls were also included to allow maximum rust severity for comparison. Terminal rust severity, average coefficient of infection, and AUDPC values of stem rust were significantly (P<0.05) reduced due to frequent fungicide application. Application of both fungicide-treated plots revealed significantly (p ≤ 0.05) higher thousand kernel weight and grain yield than the untreated check plots. Moreover, Nativo SC 300 gives the maximum grain yield and is effective in reducing stem rust across the sites. There was a significant negative correlation between TRS, ACI, and AUDPC and that of grain yield, TKW, and kernel per spike, with a correlation coefficient ranging from r = -0.85** to r = -0.33**. Cost-benefit analysis revealed that application of Nativo SC 300 (Trifloxystrobin 100 g/l + Tebuconazole 200 g/l) three times at a 10-day interval provides the highest net benefit, and it is the best management strategy to improve the grain yield or quantity of the produce.