Glyphosphate (Roundup) is a now off-patent general herbicide that will pretty much kill everything (even your crop) unless it is genetically modified a la Monsa

Glyphosphate (Roundup) is a now off-patent general herbicide that will pretty much kill everything (even your crop) unless it is genetically modified a la Monsanto's RoundUp ready crops. This is often how Monsanto finds people to sue; people that buy Roundup without buying the seeds.