Frequently Asked Questions: 

Prepared by Orit Vertesh-Burg (B.Sc) – Horticultural Consultant and vegetables Grafting Specialist  (orit@graftingclips.com)

Which clips are preferred?

The most important factor in choosing a clip is the clip’s ability to hold the grafting union tightly, but not too tightly. The strength of the clip ensures a fast and good graft union formation. Other considerations are price, labor convenience and the clip’s ability to fall off of the matured plant.

Appropriate clips for Cucurbitaceous:

Reusable clips:

  • Lower cost
  • Metal ring ensures a tight grip at the graft union point.
  • Labor convenience.

Disposable clips:

  • Save effort – no need to remove from plants.
  • Eliminate the need for sterilization.
  • No clip erosion, the clips are always at a uniform level of quality.
  • Firmness of the clip can be chosen according to the nursery’s needs.

Appropriate clips for Solanaceae:

Pipe clips:

  • Relatively inexpensive, and very economical to transport.
  • Tightly grip the graft union point thus increasing the success rate.

Silicon tubes:

  • Labor convenience
  • Flexible – they permit slight differences in diameter between scion and rootstock stems which is not the case for pipe clips.

Poly tubes:

  • A new product with a similar silicon character, but far less expensive then silicon tubes.
  • Labor convenience
  • Facilitates a slight difference in diameter between scion and rootstock stems. Firmness can be chosen according to the nursery’s needs.

Where should the healing area be located, in a closed chamber or in greenhouse tunnels?   

This question requires analyzing various parameters including weather conditions, technology skills and the seasonal capacity of the nursery.  A tunnel system can be used in a humid climate and moderate weather conditions (not overly hot in the summer nor overly cold in the winter). The layout is relatively basic and inexpensive, provided there is no need for special equipment and facilities to ensure high humidity and temperature control.   The disadvantage is that you will have an environment that is not fully controlled, as well as a loss of valuable space inside the greenhouse. A closed chamber system requires significant technical skills and extensive experience and knowledge in planning and designing the layout.  It also requires tray transportation during the acclimation stage. A closed chamber tends to be more expensive than a tunnel system. However, the considerable advantage is the fully controlled environment throughout the year, regardless weather condition.  Most of the time, the successful grafting rate is higher and the graft union formation is faster than when using tunnels. In addition, the closed chamber saves valuable space inside the greenhouse for year round production.

We specializes in design and construction of healing areas. Please contact us for more information.

What are the best practices for eliminating disease and infection?

  • Seeds must be purchased from a certified seed company.  Every lot should come with a health certificate. If a contaminated lot is purchased, the disease will spread easily during the grafting process.
  • Rootstock and scion must be very vigorous. Weak plants will have higher sensitivity to diseases and a poor survival rate.
  • Avoid non-essential handling (like spacing after grafting, or grading prior to grafting). Handling is a primary cause of disease transfer.
  • Sterilize the grafting team’s knives and hands frequently.
  • Avoid extra humidity during all stages, including the healing stage.
  • The nursery’s ventilation system is the key for healthy plants, including in the healing area. Investment in ventilation provides a very high ROI (Return on Investment).

If you are experiencing problems with diseases or infections, please contact us, we can help.

What is meant by “Incompatibility” between the scion and the rootstock?

  • Graft incompatibility is a term that relates to an interruption and/or disorder in the xylem and phloem continuity along the graft union (see also illustration of the graft union formation).  In Cucurbitaceae, this may cause graft failure in just a few daysor weeks after the acclimation stage. Apparently,  this incompatibility has been caused  by Phloem union failure between scion and rootstock, which result in insufficient carbohydrates and hormones supply to the roots. The rootstock’s stem and roots will degenerate, causing the entire grafted plant to die.

Due to our extensive experience, we can help prevent incompatibility issues via staff training and guidance.