How to Apply Fungicide to Potatoes

One word strikes fear into the potato farmer: blight. The very same disease that wiped out the potatoes in Ireland in the 1840s still ruins crops across the globe. Late blight, caused by the fungus Phytophthora infestans, is evidenced by lesions on the stems, leaves and tubers. If the weather is humid a white fuzz may appear on the undersides of potato plant leaves. Prevent late blight, which is challenging to control, by planting seed that is certified free of the disease. Irrigating properly also helps prevent the disease. The best overall protection, however is fungicide, applied for the first time to the potato plant when it reaches 4 inches in height.

Things You'll Need

• Gloves
• Protective clothing
• Breathing mask
• Tank sprayer
• Measuring spoons

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Instructions

1. • 1

     Choose a fungicide that contains mancozeb or chlorothalonil. Most nurseries and gardening centers carry these products.

   • 2

     Wear gloves, long sleeves and pants and a breathing mask when applying fungicide to the potatoes. Wash your hands after using fungicides.

   • 3

     Add the amount of water listed on the fungicide label to the spray tank. Add the fungicide and swirl the tank to mix it with the water.

   • 4

     Spray the potato plant's foliage thoroughly until the fungicide drips from the plant.

   • 5

     Reapply the fungicide every five to 10 days, unless the product label states otherwise.

   • 6

     Cease fungicide applications two weeks before you harvest the potatoes, or according to label instructions.