Publish Date: Fall 2018
Grafting is an ageold technique used in plant propagation to combine two plants so that one plant provides a desirable rootstock and the other provides desirable fruit characteristics (Fig. 1). While most people are familiar with grafting of fruit trees, grapes, roses and many other fruit and ornamental plants, they may not know that the first record of vegetable grafting was written 1500 years ago in Korea. Grafted watermelon newly transplanted into the field; the top of the grafted plant is called the scion and the bottom is the rootstock.Grafting is used for vegetable production for three primary reasons: 1) to control soil-borne diseases, 2) to overcome salinity issues, and 3) to increase crop vigor under temperature stress. In addition, depending on rootstocks, grafted vegetables can be more tolerant of saturated soils, http://vegetables.wsu.edu/ graftingVegetables.html#information, and are also available in Spanish. Seedlings are grafted when they have 1-2 true leaves, and a double edged, thin razor blade is used to cut the plants. For eggplant and tomato, the splice grafting method is used, and is rapid and simple to learn.
Grafting has been shown to be effective against several soil-borne diseases, including fusarium wilt, verticillium wilt, bacterial wilt, southern blight, and also root-knot nematodes. It is important to note that grafted vegetables do not have increased resistance to foliar pathogens. Also, grafting does not appear to have an impact on yield when there is no stress. For example, research studies with heirloom tomato at Washington State University showed grafting provided no benefit when planted in a high tunnel or a field with a low to moderate level of verticillium wilt (up to 25 colony forming units per g of soil) as tomatoes have genetic resistance, even many heirloom varieties.http://plant-clinic.bpp.oregonstate.edu/services-and-fees/.
Although grafting holds promise as a disease management strategy especially for watermelon and eggplant producers in Washington and Oregon, use is limited due in part to the cost of grafted transplants. Increased production costs related to grafting include extra seed and greenhouse facilities needed to grow rootstock seedlings, skilled labor needed for grafting, and special facilities required for successful healing of the grafted plants (Dabirian and Miles, 2017). Growers can purchase grafted transplants, see http:// www.vegetablegrafting.org/resources/suppliers/ for a list of commercial suppliers in North America.
For those interested in teaching vegetable grafting, Washington State University has developed a guide to hosting a grafting workshop, see http://www.vegetablegrafting.org/?s=grafting+manual&x=0&y=0.
For more information:
Grafting manual http://www.vegetablegrafting.org/?s=grafting+manual&x=0&y=0
Guide to hosting a vegetable grafting workshop http://vegetables.wsu.edu/Grafting_Training_ Information_Packet.pdf
Washington State University vegetable grafting research, publications and guides http://vegetables.wsu.edu/graftingVegetables.html
- Grafting Supplies WSU fact sheet.
- Vegetable Grafting: The Healing Chamber. WSU Extension Fact Sheet FS051E 3 pages. Published October 2011, reviewed July 2016.
- Vegetable Grafting: Watermelon. WSU Extension Fact Sheet FS100E 7 pages. Published January 2013, reviewed June 2016.
- Injertos Hortícolas: SandÍa. Hoja de datos de la Extensión, Universidad Estatal de Washington FS100ES. 7 páginas. Publicado enero 2014.
- Vegetable Grafting: Eggplant and Tomato. WSU Extension Fact Sheet FS052E 4 pages. Published October 2011.
- Injerto de Verduras: Berenjenas y Tomates. Hoja informativa de la Universided Estatal de Washington FS052ES. 4 páginas. Publicado Agosto 2013.
- Non-grafted and Grafted Seedless Watermelon Transplants: Comparative Economic Feasibility Analysis. Washington State University Extension publication TB08E, 14 pages. A guide for evaluating the physical and financial requirements and economic feasibility of growing seedless watermelon transplants, both non-grafted and grafted, in a greenhouse, as well as using grafted transplants to produce seedless watermelon in Washington. Published May 2016.
Dabirian, S. and C. Miles. 2017. Antitranspirant application increases grafting success of watermelon. HortTech 27:494-501 doi: 10.21273/ HORTTECH03739-17
Johnson, S. and C. A. Miles. 2011. Effect of healing chamber design on the survival of grafted eggplant, watermelon, and tomato. HortTech. 21:752-758.