9 Vision guidance systems comprised of digital camera, image analysis computer, electro-hydraulic valves, hydraulic side-shifting frames or hydraulic steering discs or wheels; control systems comprised of digital camera, image analysis computer, electro-hydraulic valves, hydraulic side-shifting frames or hydraulic steering discs or wheels for controlling lateral movement of seed drills, cultivators, sprayers and fertilized applicators; image tracking systems comprised of digital camera, image analysis computer, electro-hydraulic valves, hydraulic side-shifting frames or hydraulic steering discs or wheels; positioning and sensing devices comprised of digital camera, image analysis computer, electro-hydraulic valves, hydraulic side-shifting frames or hydraulic steering discs or wheels; control systems for operating and controlling machines based on data received from position sensing devices; on-board control systems comprised of digital camera, image analysis computer, electro-hydraulic valves, hydraulic side-shifting frames or hydraulic steering discs or wheels; computer control systems comprised of digital camera, image analysis computer, electro-hydraulic valves, hydraulic side-shifting frames or hydraulic steering discs or wheels for controlling lateral movement of seed drills, cultivators, sprayers and fertilizer applicators; computer controlled positioning and sensing devices utilizing crop foliage analysis; computer controlled systems for operating and controlling machines based on data received from position sensing devices