PPDL Picture of the Week

April 4, 2016

Grafted Tomatoes

Wenjing Guan, Horticultural Specialist, Southwest Purdue Ag Center, Purdue University

Pictures (Figure 1) presented here are a cultivated tomato plant that was grafted onto a wild tomato. The cultivated tomato plant is called scion. It is a variety that we are familiar with. It will produce nice looking tomato fruit. The wild tomato is called rootstock, we normally do not harvest fruit from rootstock plants (only if you want to know what wild tomatoes look like). Good thing about rootstock plant is that it has desirable root characteristics, such as resistance to soilborne diseases, vigorous root systems, and tolerance to environmental stresses. Because of these good root characteristics, grafted plants normally grow more vigorous and have higher yield (Figure 2).

However, grafting do not work in all cases. Although majority of tomato varieties are graft compatible with tomato rootstocks. There are occasional cases that sudden death might occur on grafted plants. One of the cases is when tomato mosaic virus (ToMV) infected scion plants that do not have resistance to ToMV while rootstock plants have. Although sudden death is not a common concern of grafted tomatoes. Grafted plants might perform poorly when foliar diseases are dominant or soil fertility is too low. When growing grafted tomatoes, production systems including densities, fertilizers, pruning and trellising might need to be adjusted to fully explore the potential of grafted tomatoes.


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Figure 1

 

Figure 2