I would be very surprised if any farmer dared to spray a growing corn crop with a harmful chemical - corn does not suffer from many problems and I can't think of a reason why it would be treated. Any pesticide would need to be food safe anyway. However for peace of mind I would check with the farmer to ask for a spraying alert. There is a product called Remay that is a light agricultural fleeced used to cover crops like cabbage that can get wormy as it keeps out flying moths that would lay eggs on the cabbage. You may want to keep this light covering available in case a crop duster (airplane spraying pesticides) appears and you feel you must protect your vegetables. Again, this seems unlikely and I would have no worries about planting vegetables next to a corn patch. Keep growing, Marianne Binetti