INTRODUCTION TO CUCURBIT AND SOLANACEOUS ROOTSTOCK TABLES
Please read the introduction and background information below. Then, click on the link to access the table listing rootstock varieties for use in commercial production of Cucurbit or Solanaceous crops.
Grafted plants of three solanaceous (eggplant, pepper, tomato) and three cucurbit (cucumber, melon, watermelon) crops are increasingly used in field and/or high tunnel-based vegetable production in the U.S. Of these six crops, grafted tomato and watermelon plants are currently used in the greatest number and on the largest number of farms. Interest in and experimentation with grafted pepper and cucumber are also rising steadily.
Rootstock (RS) varieties are available for all six crops, although the number of tomato and watermelon RS varieties currently far exceeds the number available for other crops.
More important, like fruiting (scion) varieties, RS varieties differ in traits that matter to growers. Some of these traits, such as resistance or tolerance to biotic or abiotic stress, are well-documented for many RSs. However, other RS traits, such as vigor, are less well understood but may also influence RS performance under various conditions. Soilborne disease resistance is currently what we know most about regarding RS varieties; therefore, this is how they are most often differentiated, including in these tables.
The purpose of these tables is to provide basic information on RS varieties in a catalogue-like format. The tables attempt to clarify the availability of each variety in the U.S., although availability changes often. The tables are based on information taken directly from resources (printed or web) provided by those who develop, market, and/or distribute RS varieties and/or RS seed. We recommend thinking of and using these tables as living documents, interactive master lists or “catalogues” of rootstock varieties, that save you time and effort. The tables may also prompt important questions the global grafting community will address through research, extension, and teaching.
The tables are prepared by the Vegetable Production Systems Laboratory (VPSL) at The Ohio State University. The VPSL is responsible for the tables although RS developers, marketers, and distributors are responsible for their content. No endorsement is intended for companies and/or products mentioned, nor is criticism meant for those not mentioned.
All questions about the tables should be directed to Dr. Matt Kleinhenz of the VPSL, firstname.lastname@example.org, phone: 330.263.3810.
HOW THE TABLES ARE PREPARED
VPSL staff periodically collect information on RS varieties from resources published by companies that develop, market, and/or distribute RSs and/or RS seed. We collect the information and then compile these summaries, focusing on RS varieties likely to be available. Information provided by companies remains unchanged. To obtain information, team members first complete a targeted search of RS companies and varieties included in previous tables, noting changes, as necessary. Staff then complete an open search designed to capture new companies and RSs. This stage requires approximately two months.
Next, input from companies is incorporated in a process lasting one-two months.
Finally, the tables are uploaded to the vegetablegrafting.org website for viewing and downloading. Changes are also incorporated as new information becomes available and a new table is uploaded with an updated time-stamp.
SPECIAL COMMENTS ON TABLE CONTENT
1. About rootstock varieties listed in the tables: Seed and varietal availability change often and sometimes with little notice. Still, to the best of our knowledge, varieties listed in the tables are available to vegetable growers as either seed shipped directly to the farm or a grafted plant supplier. Varieties listed in the tables may or may not be available outside the U.S. Similarly, although our long-term goal is to develop a global database of commercially available RS varieties, we currently do not attempt to identify varieties available outside of the U.S. RS varieties identified during the search process thought to be unavailable in the U.S. are included but receive special notation regarding their availability. Also, companies that supply grafted plants may be able to obtain seed of varieties not listed in the tables and to provide access to those varieties to growers, but only in the form of grafted plants.
2. About rootstock and scion compatibility: Rootstocks are specifically developed to be used with a particular crop or crops for best results. The “crop scion” column in each table specifies which crop(s) is a best match for that rootstock. There are further factors to consider when choosing a scion/rootstock combination such as how it affects plant growth, yield, and fruit quality. Consult other resources or companies directly for details about these effects.
3. About disease resistance:
A. Companies and individuals rate and define disease resistances differently. To help limit variability in this important process, the International Seed Federation (ISF), https://www.worldseed.org/, developed recommendations for defining and describing disease resistances for vegetable and ornamental crops. ISF defines two levels of resistance:
- i. High resistance (HR) = the plant can highly restrict the damage by this pest or disease, showing little to no symptoms compared to a susceptible plant under normal disease pressure.
- ii. Intermediate resistance (IR) = the plant can restrict the damage by this pest or disease but will show more symptoms than a highly resistant variety and less symptoms than a susceptible variety with similar disease pressure.
B. Our goal in developing the tables is to accurately summarize all RS varieties based on information provided by those who develop, market, and/or distribute them. Still, using the tables to compare varieties is complicated by the fact that companies and individuals rate and define resistances and tolerances differently. In the tables, when companies use language other than “HR” or “IR” to denote these standard two levels of disease resistance, it has been displayed verbatim from materials they provide. We recommend contacting companies and/or reliable local experts (e.g., extension-research personnel) with questions or suggestions for ‘interpreting’ trait listings. A partial list of university-based grafting experts is available HERE. Further, company representatives may have additional information on specific varieties not included in the tables. For example, interest in variety ‘vigor’ is increasing but little information on it (especially technical or research-based) is publicly available for most varieties.
C. In the tables, if resistance is not indicated, it means that no information was provided by the company responsible. Regardless, plant disease resistance is complex and is influenced by multiple factors. Even varieties rated as resistant can become diseased depending on the plant, environmental conditions, and levels of the pathogen. See HERE for an overview of plant diseases and resistance from the ISF and HERE for ISF’s latest update of pathogen codes for vegetable crops.
D. The common name of the disease or pest and the pathogen code are provided. Pathogen codes are those adopted by the ISF Vegetable and Ornamental Crops Working Group with strain nomenclature used in the U.S.
4. More information about varieties listed: The name and a link to contact information are provided for each variety developer or lead contact. For the solanaceous RS table, clicking on the rootstock variety takes you to a company’s page with more information about that variety. For the cucurbit RS table, an appendix has been created to increase the ease of indicating a rootstock species and the use of the tables. To view the company’s page for more information about the variety, find the variety name and select the link for the company’s website in the appendix. The variety’s species, if known, is listed next to the RS variety name.
5. After completing a brief questionnaire, tables can be printed from a PDF or a sortable Excel file of the tables can be requested.
Please visit our RESOURCES section of http://www.vegetablegrafting.org/ for information about grafting history, methods, and costs along with grafting related events and research.
Select the links below to access the questionnaires for the cucurbit or solanaceous RS table:
Text and tables were last updated March-May 2022.