A Simple Method to Improve Hazelnut Grafting

Hazelnuts are usually propagated by suckers or layering. However, other methods of propagation have been tested with variable results. Grafting is a method that has a few advantages such as fast multiplication rate, earlier fruiting and reducing sucker removal cost on specific rootstocks. Unfortunately, grafting is difficult due to slow formation of callus in hazelnuts. Here, we report the hypocotyl cleft graft as a simple method to increase the success rate of hazelnut grafting when the scion is coated with a thin layer of paraffin (wax). Two treatments, hypocotyls cleft grafting without paraffin and with paraffin, have been tested. Hazelnut variety Carmela (Corylus avellana) has been grafted on etiolated hypocotyls of native hazelnuts (C. americana). Uncoated scions had a 9% success rate, while the success rate increased nine times and was 85% when the scion was coated with a thin layer of paraffin right after grafting. This method is suggested for other nut trees such as Persian walnut, which are hard to graft.