Deere & Co on Friday missed quarterly profit estimates for the fifth-straight quarter and cut its full-year outlook, as an escalating U.S.-China trade war threatens to further hit farm incomes and demand for Deere's equipment.

Shares of Deere, known for its trademark green tractors and harvesting combines, fell 4% to $140 in premarket trading.

U.S. agricultural exports are likely to suffer, as the world's two largest economies level escalating tariffs on each other's imports in the midst of negotiations.

Earlier this week, soybean futures fell to their lowest in more than 10 years, which is squeezing U.S. farmers whose incomes have already been under pressure from a global grain glut.

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