>> Top Wedge Grafting

Application:

  • Top Wedge Grafting is commonly used for the nursery production of containerized tropical fruit trees such as avocado, passion fruit, and occasionally citrus, although the latter is most commonly propagated by T-budding. Although the carpentry of a Top Wedge Graft is similar to a cleft graft, the former usually involves placing a single non woody scion on a small diameter (<1 cm), non woody shoot of a containerized fruit tree rootstock.
  • What is the difference between top wedge and cleft grafts in terms of carpentry, time or year, etc.?
  • Top Wedge Grafting is typically used for clonal propagation of species which are otherwise difficult to clone from cuttings, etc. 
  • We have found that this easy to perform method is excellent for teaching inexperienced students how to graft.

Advantages & Disadvantages:

  • Top wedge grafting requires less skill and practice than many other grafting and budding techniques, and is easily performed on the not yet lignified (non or semi woody) shoots of young containerized fruit trees, in the nursery.
  • On the other hand , since it involves non woody, actively growing scion material, which is easily dessicated, the top wedge graft must be carefully protected from dessication. This is usually accomplished by tying a polyethylene "tent" (plastic bag) over the graft, and keeping the grat=fted plant under artificial shade to avoid dessication.

How to Top Wedge Graft:

Terminal portion of the stock plant is removed with a horizontal cut.
Stock is split vertically, several cm deep.
Scion cut into a "V" shaped wedge
Scion is inserted into the stock, with care to align cambia.
Stock and scion are tied together with plastic strip or a budding rubber.
Scion and upper portion of stock are bagged to maintain high humidity, and grown on under shade to avoid overheating.

Additional Information:

Source: Hort 400 Plant Propagation Web site autotutorial
Title: Top Wedge Grafting, adapted from Mudge, KW, A Mwaka, D Isutsa, R Musoke, D Foster, and B Ngoda. 1992. Plant Propagation, a teaching resource packet with emphasis on agroforestry and fruit trees in East Africa. Published by Department of Floriculture and Ornamental Horticulture, Cornell University, Ithaca, NY.
URL: http://instruct1.cit.cornell.edu/courses/hort400/4tutos/topwedg1.html
Comments:This series of annotated slides illustrates the use of top wedge grafting of avocado and other tropical fruit trees.

Source: HWWG Laboratory Exercise
Title: Top Wedge Grafting
URL: TWGLabFrm.html
Comments: Laboratory Exercise for this course