Prices for U.S. farm exports fell 5.3 percent from June to July, the biggest drop since October 2011, according to Labor Department figures. Soybean prices fell 14.1 percent, and prices for corn, wheat, fruits and nuts also slumped. China has targeted all of those products and others with tariffs in retaliation for U.S. tariffs.

"The report also showed that import prices were unchanged from the previous month, matching the median estimate of economists. Prices were up 4.8 percent from a year earlier, the biggest advance since 2012, driven by a 40.7 percent rise in fuel import prices," Jeff Kearns reports for Bloomberg.