From the Ohio State University Vegetable Newsletter
Matt Kleinhenz, Department of Horticulture and Crop Science, The Ohio State University
Many articles, including one in the June 21 edition of VegNet, have stated that grafted fresh market tomato plants can out-yield ungrafted ones by up to 50% or more depending on the circumstances. Those circumstances appear to include abiotic and biotic stresses that also occur in processing tomato production in Ohio and elsewhere. In some tests, grafted fresh market tomato plants have also out-yielded ungrafted ones when lower rates of fertilizer were used.
So, at first glance, it seems obvious that grafted plants will also be useful in processing tomato production. However, that has not been proven. Clearly, more information is needed to understand the value of grafted plants in processing tomato production. Their value is increasing in fresh market production and their potential to enhance processing production is real. That said, differences between fresh market and processing tomato production, including their economics and varieties, requires the value of grafted plants in processing production to be validated separately. Grafting effects on processing tomato yield, quality, and profit potential must be tested thoroughly.
Growers, researchers, and others must do the testing. Teams in California and Ohio have started. Currently, as described in Figure 1, plots at the OARDC in Wooster, OH contain plants representing thirty rootstock-scion variety combinations and ungrafted plants of the fruiting (scion) varieties. We are tracking crop development and we will record fruit yield and quality, including color and soluble solids. Our work is supported by The Ohio Vegetable & Small Fruit Research & Development Program (OVSFRDP), the USDA-SCRI program, The OSU-OARDC, and the Department of Horticulture and Crop Science. We will be happy to assist growers with tests on their farms. Contact Matt Kleinhenz (ph. 330.263.3810; firstname.lastname@example.org) for more information. Also, see resources at http://www.vegetablegrafting.org/ for additional information.