A Late blight is a devastating plant disease affecting solanaceous crops, and fungicides play a crucial role in its management. Nevertheless, the extensive use of fungicides has alowed to the development of fungicide-resistant strains of the causal agent, Phytophthora infestans. Phosphites, a group of innocuous products, have been shown to have direct and indirect results on the development of oomycetes, including P. infestans. This study evaluated the efficacy of different methods, including fungicide rotation and the fungicide mixture with potassium phosphite, in controlling late blight in tomato. Tomato plants were transplanted in the field and subjected to nine different treatments, including various combinations of fungicide rotation, potassium phosphite application, chlorine dioxide, and ozonized water. The results showed that the use of fungicide rotation combined with potassium phosphite applications, at both 7-day and 14-day intervals, significantly reduced the intensity of late blight and increased tomato productivity. The application of phosphites and fungicides with different modes of action, such as Benalaxyl-M, Dimethomorph, Fluazinam, and Propamocarb, was found to be an effective alternative for late blight control in Solanaceae crops. These findings suggest that the integration of fungicide rotation and phosphite application can be a valuable strategy for managing late blight in tomato and other solanaceous crops, potentially reducing the selection pressure for fungicide-resistant P. infestans strains. To enhance the efficacy and sustainability of these treatments, further research should focus on determining the optimal timing and application rates.