If you notice white smoke coming from your John Deere tractor, there are a few potential causes. One possibility is that the tractor is burning oil. This could be due to an oil leak or overfilling the oil. Another possibility is that the tractor is burning coolant. This could be due to a coolant leak or the coolant getting too low. If the tractor is low on coolant, it will need to be refilled. If there is a coolant leak, it will need to be repaired. Finally, the white smoke could be due to the tractor being too cold. If the tractor is cold, it will need to be warmed up before it will run properly.