[justsomeperson]

weeding and pest control is where the real utility for a farm robot would come in.

[sgt]

Yes, good point. Does this open source farm robot spray pesticide?

[KaiserPro]

Shouldn't need too, if you know where you've planted then you can kill any plant that's growing in an unknown place.

For all the other types of pest, you really don't want to be automatically spraying that, you're one software bug away from having a very bad day.