Agricultural and Biological Research

Evaluation of bread wheat (Triticum aestivum L.) genotypes for yellow and stem rust adult plant resistance and disease impact on grain yield

Demeke Zewdu* and Kedir Yimam

Wheat is a self-pollinating annual plant, is extensively grown for staple food in the world. Yellow and stem rust of wheat are the most important fungal diseases of wheat and the major production challenges in the major wheat producing regions of Ethiopia. The present research was conducted at Kulumsa for yellow rust and Dera for stem rust in 2021 with the objective to evaluate bread wheat genotypes for yellow and stem rust adult plant resistance and to assess the diseases impact on grain yield in the natural field condition. Based on final rust severity for yellow and stem rust severity showed from immune 0 to 90%, for yellow rust 51 genotypes showed high adult plant resistance (1-20% of severity), 4 genotypes observed as medium adult plant resistance (21-40% of severity) and 9 genotypes observed as low adult plant resistance (>41% of yellow rust severity), for stem rust 44 genotypes showed high adult plant resistance (1-20 % of severity), 8 genotypes observed as medium adult plant resistance (21-40 % of severity) and 12 genotypes observed as low adult plant resistance (>41% of stem rust severity). Tested genotypes showed diverse reactions for yellow and stem rust ranging from Resistance (R) to Susceptible (S) responses. The regression analysis showed that when the yellow rust severity changes within a unit the grain yield decreased by 35.871 kg/ha and when the stem rust severity changes within a unit the grain yield decreased by 18.574 kg/ha. The correlation analysis also revealed that grain yield had negative significant correlation with yellow rust (r=-0.78) and stem (r=-0.67) disease severity and Area Under the Disease Progress Curve (AUDPC). Genotypes 2 and 46 had maximum grain yield 6.07 t/ha and 5.67 t/ha with low yellow rust AUDPC value 35 and 0 respectively. Genotypes 30 and 4 had maximum grain yield 3.94 t/ha and 3.85 t/ha with low stem rust AUDPC value 0 and 21 respectively.