What is essential in preventing resistance development when using fungicides?

Applying fungicides only as needed and rotating modes of action is essential in preventing resistance development. When fungicides are overused or used repeatedly without a change in active ingredient or mode of action, pathogens can adapt and develop resistance, rendering the fungicides ineffective. By applying fungicides only when disease presents itself and ensuring that different modes of action are utilized, the selection pressure on the pathogens is reduced. This approach helps to maintain the efficacy of fungicides and manage disease effectively over the long term, preventing the establishment of resistant strains that could compromise control measures. This practice is a cornerstone of integrated pest management strategies, promoting environmental sustainability and preserving the effectiveness of fungicides.