Comparative Evaluation of Artificial Inoculation Techniques for Powdery Mildew (Blumeria graminis f. sp. tritici) in Wheat

Abstract

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is a major foliar disease of wheat that significantly affects crop productivity worldwide. Standardisation of an efficient artificial inoculation technique is essential for reliable disease establishment in resistance screening, epidemiological studies, and disease management research. The present investigation was conducted during the 2024–2025 Rabi season under glasshouse conditions to compare four artificial inoculation methods—spraying, brushing, rubbing, and dusting—using the susceptible wheat cultivar PBW 343. The experiment was laid out in a completely randomised design with three replications, and disease severity was assessed at weekly intervals using the 0–4 infection-type scale of Smith and Blair (1950). Significant differences among the inoculation methods were observed throughout the experimental period. During the first week after inoculation, rubbing recorded the highest disease severity (1.67), followed by dusting (1.33), spraying (1.16), and brushing (0.67), whereas no symptoms were observed in the control. In the second week, disease severity increased to 2.50 for rubbing, 2.33 for dusting, 1.67 for spraying, and 1.33 for brushing. By the third week, rubbing and dusting each produced a disease severity score of 3.50, followed by spraying (2.50) and brushing (2.17). In the fourth week, rubbing resulted in the maximum disease severity (4.00), followed by dusting (3.83), spraying (3.50), and brushing (3.17), while the control recorded 2.00. The overall mean disease severity was highest for rubbing (2.92), followed by dusting (2.75), spraying (2.21), brushing (1.83), and the control (0.96). The superior performance of rubbing was attributed to the efficient transfer of viable conidia, ensuring rapid, uniform, and reproducible infection. Under the study conditions, rubbing was the most effective and dependable artificial inoculation technique for B. graminis f. sp. tritici and may provide a standardised protocol for wheat resistance screening, host–pathogen interaction studies, epidemiological investigations, and the evaluation of disease management strategies.