Shares of Lamb Weston (LW -21.70%) -- North America's largest potato producer -- were sliding again after it delivered third-quarter results before the start of Thursday trading that missed estimates, offered weak guidance, and said it was replacing its CEO.As of 11:37 a.m. ET, the stock was down 21.2% on the news. Lamb Weston's problems are multiplyingLamb Weston's revenue in the quarter fell by 8% year over year to $1.6 billion, which missed the consensus estimate of $1.67 billion. The underperformance ca ...