How to Prevent/Manage Fungicide Resistance?
Cultural practices play a big role in preventing or managing resistance to mefenoxam. • Select areas with well-drained soils to avoid conditions favorable for both pink rot and leak. • Use crop rotations out of potatoes for at least 4 years. Even one year out of potatoes will drastically reduce soil fungal populations, as the previous potato crop produces most pink rot inoculum. • The level of resistance to pink rot is predictable from tuber isolations. By having tubers tested, growers can differentiate between resistance and lack of control due to application or persistence problems. • Pythium leak invades the tuber through wounds that occur during harvest. Avoid harvesting potatoes when soils are especially wet or when flesh temperatures are high (> 68 F), as leak development under these conditions is very rapid. Adjust harvesting equipment to keep digger chains fully loaded and minimize drops to 6 inches or less.
