Many people don't like the biting taste of mustard. Neither, it turns out, do sting nematodes—small, parasitic roundworms that siphon food from plant roots. That finding could prove good news for maintaining golf courses, sports fields, and other picture-perfect lawns.
Some weeds and other plants naturally resist sting nematodes (Belonolaimus longicaudatus Rau). Suspecting that these plants produce defensive chemicals, Campbell J. Cox and his colleagues at Clemson (S.C.) University applied extracts from several of these plants and a few other candidates to the roundworms in test tubes and greenhouse soils. The group included spotted spurge, tall lettuce, goldenrod, lantana, poinsettia, and a mustard.