Abstract
Golovinomyces cichoracearum is the most widespread fungal pathogen causing severe disease in sunflower plants. This investigation demonstrated the evaluation and efficacy of multiple eco-friendly treatments, including plant extracts of Rosmarinum officinalis and Datura stramonium, essential oils of Nigella sativa and Origanum majoronum, compared with salt compounds of potassium phosphate; copper sulfate, magnesium sulfate, and a conventional systemic fungicide Punch (Flusilazole), for controlling powdery mildew disease on sunflower plants in the greenhouse. Our results indicated that the most successful treatments were fungicide Punch, KH2PO4, K2HPO4, and MgSO4, which reduced disease severity by 89.58%, 85.33%, 74.08%, and 68.04%, respectively, compared to control plants. Alternatively, O. majorana, D. stramonium, N. sativa, and CuSO4 reduced the disease severity by 57.88%, 57.1%, 54.72%, and 54.48%, respectively, while R. officinalis was the least effective treatment, reducing the disease severity by 37.8%. The four most successful treatments were further explored in the field using naturally infected sunflower plants. Effective treatments significantly reduced the severity of powdery mildew disease compared to the control. The conventional fungicide Punch and salt compound KH2PO4 were the most efficient treatments compared to other treatments. In naturally infected plants, the foliar application of fungicide and salt compounds altered the protein profiles and isozyme patterns compared to the untreated healthy control and naturally infected control, indicating the development of systemic resistance. Our results demonstrated that salt compounds KH2PO4, K2HPO4, and MgSO4, showed an auspicious effect toward powdery mildew disease severity reduction compared to the conventional fungicide. Therefore, the use of phyto-extracts and chemical inducer compounds can develop host resistance and may provide a more eco-friendly approach to control phytopathogens than conventional fungicides.