The experiment was performed in the
conditions of a home garden, meaning I had limited space, containers and beds
of various sizes, unequal lighting, and other limitations, making the data
imperfect. In addition, I had only one specimen of each experimental sample. Nevertheless, I set out to
answer: do I get a better yield from grafted tomato plants? – and the answer is
yes. Grafted plants produced more tomatoes. Supernatural rootstock was used for
all grafted plants.
EXPERIMENT
A total of 34 plants were analyzed in the
summer of 2014 in Davis, California. 22
plants were in 11 pairs (grafted and selfrooted) representing 11 different varieties,
planted in the same container or bed, and kept single-stemmed, so I could
discriminate the yield between plants in the same container. The other 12
“single” plants were growing in their own pots or beds and were also kept
single-stemmed, so their growing conditions are comparable with the paired
plants. 7 of
them were grafted, and 5 were selfrooted.
RATIONALE
I grow exotic heirloom cultivars. Here
are some of them
from 2012-2013.
THE PROBLEM
I faced noticeable harvest decline in 2013 for some varieties.
Ukrainian Heart and Russian were
producing significantly
less.
The plants were grown in the same pots or
beds as in 2012.
QUESTION
Does grafting heirloom tomatoes improve
yield?
EXPERIMENT was performed in 2014, in Davis,
California
The yield
was recorded for 5 months of fruiting period for grafted
and selfrooted
plants (Harvest from June 11 to November
10)
PLANTS
All paired plants were grown in the same
pot or bed and kept as single stemmed plants
The pots used for different pairs could
be of different sizes;
also, different
garden locations differ in the amount of sunlight.
This should not matter when comparing plants from the
same pot.
DATA COLLECTION
The harvest is recorded in grams per day
from each plant.
Two small-fruited cultivar pairs, Blush
and Galina, became multi-stemmed in late summer/fall. From this moment, the
harvest is recorded per pair, as it was impossible to discriminate the yield
between plants in the same pot. For the
comparative analysis, only the data before this point is used. Here is an example.
SUMMARY STATS IN GRAMS
From 11 pairs
(grafted and selfrooted in
the same pot or bed)
55% increase on average for grafted when
in pair with selfrooted in
the same pot.
From 7 single grafted plants
From 5 single selfrooted plants
114% increase on average for grafted when
in its own pot, as compared to selfrooted plants.
YIELD FROM PAIRED PLANTS IN GRAMS
NOTES ON SMALL FRUITED
Only Blush showed some yield benefit when
grafted. We liked the taste of Blush and
plan to grow it grafted next year.
Galina probably does not need grafting. I may try to use
Galina as rootstock next year. This is an Asian-type tasting tomato, and not
everyone liked it. We liked it a lot and
will grow it selfrooted next
year.
We will not grow small fruited #2 again
because the taste was bland. The seeds
came from tomatoes purchased at a local tomato farm.
NOTES ON MEDIUM FRUITED
Indigo Apple. We
liked it a lot, but this variety is not for everyone. It has a significant smoky flavor. The grafted plant delivered significantly
fewer tomatoes, so I will grow it on its own roots next year. This variety is not resistant to RKN, but
grafting reduced yield for this pair.
Mother Russia. A very good tomato with a balanced
flavor. I will grow it grafted next
year.
Sioux did
not perform well, but I had only a selfrooted plant. I will not grow it next year.
F3 #4 is a
green-striped elongated tomato with a smoky flavor. We liked it, but it is not for the majority
of consumers. I will take it to F4 if I have space and time. I may do grafting.
LARGE FRUITED, yield in grams
