Development of tensile strength in compatible and incompatible sweet cherry graftings

Abstract

The tensile strengths of graftings between three selected sweet cherry cultivars and five selected cherry rootstocks were determined with an Instron instrument 6, 12, and 18 weeks after grafting and compared with the tensile strength of self-grafted rootstocks and graftings of rootstocks used as scions. The combination of sweet cherry cultivars and rootstocks was selected to provide a range of compatibility based on preliminary work. The tensile strengths of sweet cherry cultivars grafted on different rootstocks never exceeded the tensile strengths of the self-grafted rootstocks. Rootstocks grafted as scions on Prunus avium L. rootstocks and self-grafted rootstocks produced some of the strongest unions tested and also produced union strength much faster than any of the other combinations. The degree of compatibility was quantified and results indicated that if this value was below 0.2, measured 18 weeks after grafting, it corresponded to combinations with major risks of delayed incompatibility.Key words: tensile strength, grafting, compatibility, sweet cherry, Prunus avium.