Grafted 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.

An example Plug Connection grafted plant. Notice the sturdy, stocky shoot morphology, large root mass, and seamless graft union.