In 2017 and 2018, we examined different techniques to improve the production of grafted tomatoes. Specifically, we compared 4 rootstocks (Beaufort, Arnold, Shield, and Fortamino [2018 only]), 2 scion varieties (Mountain Fresh Plus, Tasti-Lee), pinching and non-pinching, pruning and non-pruning (Beaufort only; all others were pruned), and spacing (22″ and 24″). All treatments were compared to a grower standard (both varieties, non-grafted, non-pinched, pruned, and spaced at 18″ in-row spacing).
Overall, yields improved with vigorous rootstocks (Beaufort, Arnold, and Fortamino), but were not improved with Shield. Both scion varieties yielded similarly overall. Pruning hurt yields, particularly when plants had been pinched. Grafted plants spaced at 22″ yielded similarly to 24″. Pinched plants increased yields in 2018, but not in 2017. This practice still needs some research for optimizing success.