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.