Final yields were used to determine the effect of oil sprays on potatoes. The response to six non-emulsified oil sprays applied weekly beginning with plant emergence at 1/2 gal per acre and increasing to a maximum of 4 gallons per acre varied with the variety. Avon, Fundy, Pontiac and Sebago showed increased Grade A yields, whereas Canso, Green Mountains, Katahdin, Kennebec and Netted Gem yields were reduced. Netted Gem was the variety most adversely affected. Doubling the amount of oil drastically reduced yields of Canso and Katahdin.