Bayer has told U.S. lawmakers it could stop selling Roundup weedkiller unless they can strengthen legal protection against product liability litigation.

Ban part of controversial plan to reduce reliance on GMO corn for human consumption
Recent court decisions have threatened farmers' abilities to use some herbicides
Company has won 13 of last 20 cases; plaintiffs have won more than $4 billion
Losing battle with weeds adds pressures to farmers already stressed by inflation, extreme weather
Decision important in ongoing lawsuits, Bayer says
Current approval expires Dec. 15
Canada 'considering its next steps'
Analysts say dry weather conditions hurt farmers' demand for seeds and pesticides