Tuesday, November 10, 2015

Tomato yield on different rootstocks

In the summer of 2015 I conducted a very small scale experiment to check if I should be exploring anything other then Supernatural rootstocks for grafting the cultivars I grow in my yard. Last year's (2014) experiment convinced me that grafting tomatoes is the way to go for my tomato plants, in the conditions of my yard.  Last year's results are at:  http://fruitsandgardening.blogspot.com/2014/12/performance-evaluation-of-grafted.html

This summer, along with Supernatural, I also used RST-04-105, and cultivar Galina as rootstocks.

The reason I used Galina as a rootstock was that  Galina plants did not show nematode infection last year, and I was hoping that this cultivar might be RKN resistant.

The early problem I encountered with RST-04-105 was its slow growth in the first few weeks after germination.  This rootstock should be sowed a week or two before the scion cultivars to reach the same stem diameter.  I had all seeds started at the same time, and this reduced the grafting success on RST-04-105.

The cultivar Cosmonaut Volkov was successfully grafted to all three rootstocks, and cultivar Pork Chop to only two, Supernatural and Galina.  The tree plants of Cosmonaut Volkov were planted in the same container, and two plants of Pork Chop in another one. All plants were kept single-stemmed, so I could discriminate the yield between plants in the same container. The harvest was recorded in grams per day from each plant.

Here are the results:

I will continue using Supernatural as rootstock for most of the cultivars that I grow. For the Pork Chop, the higher yield obtained on Galina roots looks interesting, and I may try it again next year. From last year's data for Pork Chop I had 2093 and 1608 grams of fruit for grafted and selfrooted plants, respectively. This year's 4427 g on Galina looks impressive. Unfortunately, I found the Galina cultivar to be not resistant to RKN. The Galina roots in these two particular containers used for this experiment were free of nematodes, but I found RKN infected Galina roots in other locations of my garden.  There is still a chance that Galina might tolerate RKN well, and it might be a more suitable rootstock for Pork Chop than Supernatural.

In agreement with the last year data, Cosmonaut Volkov cultivar was fruiting for a longer period than Pork Chop.  The harvest charts are below:

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