Grafting is a horticultural technique used in vegetable production to improve crop yields and manage diseases. It involves joining two plants: the scion, selected for its desirable fruiting qualities, and the rootstock, chosen for its resistance to diseases, nematodes, and challenging soil conditions as well as its ability to enhance plant vigor and productivity. By combining these strengths, grafting creates more resilient plants, resulting in healthier crops, increased yields, and increased agricultural efficiency.

Study Objectives

• Showcase the benefits of growing grafted tomato plants for commercial production
• Determine the viability of grafted tomato rootstocks in southwest Alabama
• Determine yield benefits provided by grafted plants

Disease Package

Costs

The Trial

Planting Date: April 12, 2023

In-Row Spacing: ~ 20 inches. Harvest Dates: June 29, July 5, 13, and 19 (2023)

Location: Brewton Agricultural Research Unit (Escambia County, Alabama)

Crops were managed according to best management practices for commercial tomato production.

Results

Figure 1. Total yield by weight of each rootstock (32 plants per rootstock).

Grafted tomato plants Bowman and Armada had the most marketable yield by weight compared to Shin Cheong Gang and the nongrafted Red Snapper. Bowman had more X-Large fruit than the nongrafted Red Snapper. There were no statistical differences between the amount of cull fruit in the study. Fruit splitting was a significant source of culled fruit from heavy rains during the harvest season. It was observed that there was more splitting associated with grafted plants. This may be due to the extensive root system that these rootstocks exhibit. All the plants received damage from a hailstorm in early June, increasing the number of total culls.

This trial had 128 plants total, with 32 plants of each rootstock for the trial. Figure 1 shows the total yield per rootstock. Bowman had the most marketable fruit with 13 pounds per plant, 12 of which were Jumbo and X-Large fruit. This rootstock had the highest number of culls at 3.2 pounds per plant. When comparing Bowman to nongrafted plants, Bowman produced 3.75 more pounds per plant than the nongrafted plants. Armada had the second highest yield by weight, with 12.2 pounds per plant of marketable fruit. The rootstock Shin Cheong Gang produced 10.9 pounds per plant of marketable fruit but had 3.2 pounds of cull fruit per plant.

Observations

• Grafted plants, especially Bowman, produced more marketable yield than nongrafted Red Snapper.
• Fruit splitting was a significant issue due to heavy rains, with more splitting observed in grafted plants.
• All plants suffered hail damage in early June, increasing the number of culls.

Conclusion

Grafted tomato plants can be a viable solution for growers with limited space to rotate out of solanaceae crops. The tested rootstocks offer excellent disease resistance, particularly against bacterial wilt, making them a valuable tool for continued production on diseased land.

Advantages:

• Reduced pesticide dependence
• High marketable yield
• Disease resistance

Considerations:

• Higher cost of grafted plants
• Potential need for cooperative ordering to manage costs
• Option to graft your own plants to reduce costs

Recommendations

For growers with diseased soil:

• Consider using grafted plants to continue production.
• Rotate crops and, if feasible, fumigate soil to reduce pathogen load.

Jacob Kelley, Extension Agent, ACES-AFNR-Field, Auburn University

New June 2025, Grafted Tomato Trial: Data & Insights, ANR-3157