I stopped by a large produce grower in my area, Maddox Sweet Corn Farm, and Ted showed me their grafted versus non-grafted heirloom tomato trial. In the photo (photo credit: D. Gucker Illinois Extension 2024), the row of tomatoes on the left and the row on the right are the same tomato variety. The difference is the row on the right was grafted to the rootstock of a tomato that is resistant to soil-borne diseases. Both rows were planted the same day and have received the same fertility program. In addition to the difference in size, the grafted row has green tomatoes and the non-grafted does not. It will be interesting to see at the end of the year whether there is a yield difference between the grafted and the non-grafted, and whether it covered the additional cost of grafting.