A few years ago farmers started noticing their crops were developing damaged leaves. Turns out the culprit was dicamba, a weedkiller being sprayed by other farmers. Now a trial is underway to decide who's responsible. The farmer behind the lawsuit is pointing the blame, not at other farmers, but two big companies, Monsanto (now owned by Bayer) and BASF. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at shortwave@npr.org.