Sprays to Control Pests on Potatoes

Seed Treatments

• Although the majority of sprays are used on plants, sprays for potato seed provide a "better, more uniform, crop of plants," according to the University of Maine. Sprays for seed treatment provide either disease or insect control. Fungicides for the control of diseases include the chemicals chlorine, mancozeb, fludioxonil, flutolanil, mefenoxam, Bacillus subtilis and thiophanate-methyl. These fungicides prevent new fungi from infecting seed potatoes, but do not kill existing fungi already in the potatoes. Growers also use insecticide sprays in order to help prevent insect damage to seed potatoes. Applications of chlothianidin and thiamethoxam provide insect control when applied according to label directions.

Herbicides

• Weed management through the use of herbicides improves potato yield by reducing competition. Weeds often act as host plants for insects and disease. Growers use herbicide sprays, cultivation and hilling practices in managing weeds in potatoes. The type of herbicide spray used depends on the time of application and the type of weeds present. Sprays considered safe for potato plants include carfentrazone, metolachlor, paraquat, dimethenamid, glyphosate and rimsulfuron.

Insect Control

• Many gardeners consider potato-related pests as difficult to kill through the use of pesticides. For example, the Colorado potato beetle rapidly develops resistance to insecticides, making it a serious problem for many growers. Spray insecticides reduce the soil-leaching potential associated with granular insecticides. Numerous sprays for potatoes exist and are used according to the type of insect, the plant stage of growth and the weather conditions. Approved sprays include abamectin, acetamiprid, cyfluthrin, endosulfan, thiamethoxam and many others.

Disease Control

• Fungicide sprays control early blight and late blight from destroying potato crops. Both forms of blight are common. Blight left untreated can spread throughout an entire potato planting, reducing harvest amounts. Growers apply fungicides when disease conditions are favorable or when the disease is already identified in the field. Fungicide sprays include boscalid, chlorothalonil and zoxamide. Metals such as copper and tin are often included in blight-reducing fungicide sprays.