Variety development is time-consuming, expensive, and technically-demanding. It can also be limited by barriers to the movement of genes and traits from one generation to the next. Grafting can bypass some of these barriers to making superior genetics available to farmers. The grafting process quickly and directly combines the traits of two plants, one providing a root system (rootstock) and the other providing a shoot (scion).

Why would a farmer consider using grafted vegetable plants? Some benefits are well-known and others may yet be discovered. Currently, grafted plants often display greater levels of vigor and tolerance or resistance to various types of stress than their ungrafted counterparts. As a consequence, fruit yield and income potential are maintained when growing conditions might otherwise reduce them (e.g., when soilborne disease organisms are present). Grafted plants may require fewer pesticide applications and emerging evidence suggests that grafted plants may uptake and/or use water and nutrients more effectively.

Grafted vegetable plants have been used for many years in many locations. Grafted plants are a staple in hydroponic greenhouse production, increasing in high tunnel production, and under greater and greater evaluation in open field systems. Grafted plants are a tool that can be used by many; they can be used on operations of all sizes, types (conventional, organic), and locations. In addition, preparing grafted vegetable plants has become a business for some.

As when using any crop production tool, employing the proper technique when preparing and using grafted plants is required to benefit from the time, effort, and expense involved. Grafting is essentially organ transplantation, therefore, it is important to pay attention to rootstock-scion compatibility, cleanliness, healing, and related issues.

Cantaloupe, cucumber, tomato, and watermelon can be grafted with a high rate of success. Information at this website focuses primarily on the preparation, testing, and use of grafted tomato plants. Information on other grafted crops will be included shortly. We invite you to look around the site and to comment on what you find (and don’t find)!

Galleries

Grafting Process

Grafting Plants

: This grafted plant is healthy as evidenced by a stable and straight graft union and the growth of the shoot (note new and larger foliage) and root (note larger rootstock stem). Flaring at the sides of the rootstock is not uncommon. The home-made plastic clip is being removed naturally by the growth of the grafted plant stem.

: Some have been successful at grafting two scion seedlings to one rootstock seedling. Rootstock varieties can be vigorous enough to support the growth of two scion shoots. These so-called double-headed grafts can increase the return on investment in rootstock seed and, possibly, reduce the number of grafted plants required per acre. More research on double-headed grafts is required.

: Shoots are arising from the stump of rootstock seedling. Removing these sucker shoots is recommended as they reduce marketable yield (rootstock fruit are typically unsaleable) and often overwhelm scion shoots and disrupt normal field procedures.

: The small shoots arising from the graft union can be either rootstock or scion in origin. Regardless, they should be removed by pinching or snipping being careful to use clean fingers or tools.

: A perfect graft in which the transition from rootstock to scion seedling is barely visible several weeks after grafting.

: The graft was unsuccessful as the scion seedling has died and broken down. A new shoot has arisen from the rootstock and is typically considered useless. This plant should be discarded.

: Healthy, grafted seedlings approximately 10-14 days after grafting. Seedling color, stature, and new leaf growth suggests that all graft unions are healing properly. Note that the scion stem diameter is smaller than the rootstock stem diameter in all cases; this discrepancy is not ideal but can result in a healthy grafted plant. Grafts involving a rootstock stem diameter that is smaller than the scion stem diameter are rarely successful.

: Small grafted tomato plants in field

: Large grafted tomato plants in field

: Grafted tomato plants with fruit in field

: Grafted tomato plants with fruit in field

: Grafted tomato plants in high tunnel

: Grafted tomato plants in high tunnel

: Grafted tomato plants in high tunnel

: Grafted tomato plants with fruit in high tunnel

: Grafted tomato plants with fruit in high tunnel

: Grafted plants tend to be more expensive but more productive than ungrafted ones. Perhaps overall profit potential and yield can be optimized through using specific plant densities and configurations. Grafted and ungrafted plants in this 30 ft x 80 ft high tunnel are arranged in low- and high-density groups based on in-row spacing.

: The historical frost-free date in Wooster, OH has been May 18. Changes in the USDA Plant Cold Hardiness Zone map and recent weather patterns suggest the date may change. Grafted and ungrafted plants in this unheated high tunnel are growing well since their May-1 planting.

: Grafted plants may take up nutrients from the soil more efficiently. Zones differing in fertility programs and containing grafted and ungrafted plants have been established in VPSL high tunnels.

: The VPSL has grafted many tomato plants for experimental and demonstration purposes each year since 2005. In 2012, we are pleased to work with an impressive group of plants provided by Plug Connection (http://www.plugconnection.com/). Here, the shipment is shown on arrival from California on May 10.

: As the demand for grafted plants increases, they will need to be shipped in more and more configurations and under more and more conditions. The Plug Connection plants shown here were two days in transit (air freight California-Atlanta-Cleveland-Wooster) and show no obvious evidence of stress.

: Within minutes of arrival, trays of 100 uniform grafted plants each are unpacked, irrigated and ready for planting or holding until field conditions allow.

: The grafted plants are labeled according to their assigned experimental plot and readied for transport to the field.

: These Plug Connection grafted plants contain a seamless transition from rootstock to scion evident as a change in color in the region of the splice graft.