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2. ENGINEERING AND TECHNOLOGY
Fraxinus excelsior (common ash) is a hardwood tree, native to Ireland which has demonstrated adaptability to growing in a wide range of sites. In 2013, there was a total of over 20,000 hectares recorded under ash in Ireland. From an economic, ecological and carbon aspect ash is also a very important tree species. Since the arrival of Chalara disease, which has the potential to prove fatal to c.97% of the ash population there is an urgent need to consider how to preserve the remaining resistant trees and propagate new resistant lines. Grafting is the suggested method which has the capacity to produce a tree in a breeding programme which can be field planted within a year, once suitable rootstocks can be determined and produced. This thesis examined the potential for grafting two Fraxinus excelsior clones M72 and 98, chosen at random onto F. excelsior, F. paxiana, F. chinensis, F. japonica, F. platypoda, Syringa vulgaris, and Ligustrum ovalifolium rootstocks to confirm their suitability for large scale vegetative propagation. It was found that when Clone M72 and Clone 98 were grafted onto Fraxinus excelsior rootstocks the survival was 100% and 97% respectively, while the non-grafted Control returned a plant survival rate of 93%. When Clone M72 was grafted onto Fraxinus chinensis and Fraxinus paxiana rootstocks the resultant graft survival was 68% and 40% respectively. When Fraxinus platypoda and Fraxinus japonica interstocks were used for grafting Clone 98 survival was 87% and 60% respectively. When Ligustrum and Syringa rootstocks were used to propagate Clone M72 survival was 37% and 33% respectively. When Ligustrum and Syringa were used as rootstocks for Clone 98 the result was 30% and 40% respectively. Propagation by budding was not successful.
McNamara, J. (2019) The Effects of Intraspecific, interSpecific, and Intergeneric Grafting on the Growth and Development of Fraxinus Excelsior Scions, Masters Thesis.