EVALUATION OF GRAFT COMPATIBILITY BETWEEN QUINCE ROOTSTOCKS AND PEAR SCIONS

Commercial pear varieties worldwide are grafted on rootstocks of Pyrus and Cydonia. Quinces rootstocks have been widely used due to two beneficial characteristics provided to the scion tree as size reduction and yield precocity.
However, most pear cultivars exhibit graft incompatibility when grafted on quince rootstocks due to physiologic and biochemical factors.
Aiming to compare compatibility levels, 41 five-year-old scion/rootstocks combinations trained in medium/high density (2000 trees/ha) were measured in the region of Pelotas – RS, Brazil during 2007. The pear cvs. tested were ‘Carrick’, ‘Seleta’, ‘Packham’s Triumph’ and ‘William’s Bon Chretien’; and the rootstocks were Pyrus calleryana and 19 quinces cvs: ‘Adams’, ‘Alaranjado’, ‘Alongado’, ‘BA 29’, ‘Bereczcki’, ‘Champion’, ‘De Patrans’, ‘Du Lot’, ‘D’Angers’, ‘Vranja’, ‘EMC’, ‘Inta 267’, ‘Lageado’, ‘Maçã’, ‘Melliforme’, ‘PineApple’, ‘Portugal’, ‘Radaelli’ and ‘Smyrna’. Evaluations were performed by visual observations and measurements of the graft-point development (mm), five cm above and five cm below.
Experimental design utilized was a randomized complete block with three replications of five trees each.
The largest trunk diameters of ‘Carrick’, ‘Seleta’ and ‘William’s’ (42.56, 59.29 and 45.74 mm, respectively) were provided by the rootstock P. calleryana. Regarding to scion trunk diameter in relation to the rootstocks: 1) ‘William’s’ had the smallest diameters with the utilization of ‘EMC’, ‘Portugal’ and ‘Radaelli’ (16.42, 16.57 and 17.64 mm, respectively); 2) ‘Packham’s’ had the smallest diameters provided by ‘EMC’, ‘Portugal’ and ‘Adams’ (15.03, 17.34 and 19.09 mm, respectively); 3) ‘Carrick’ was affected by lesser trunk development when raised on ‘Alaranjado’, ‘Du Lot’, ‘Adams’, ‘Bereczcki’ and ‘Champion’. ‘Portugal’ and ‘EMC’ had a considerable visual and measured incompatibility whether grafted into ‘Carrick’. For ‘Packham’s’ this incompatibility was observed with the use of P. calleryana, ‘Adams’ and ‘Portugal’. Among the interactions for ‘Seleta’ only P. calleryana did not show accentuated hypertrophy in the graft-point.
In the ‘William’s’ combinations this hypertrophy was more pronounced when grafted on rootstocks ‘EMC’, ‘Bereczcki’, ‘Champion’ and ‘Melliforme’. Requesting for a better visualization and confirmation between quince/pear compatibility, further evaluations will be necessary observing the development and behavior of each interaction scion/rootstocks.

VIII International Symposium on Temperate Zone Fruits in the Tropics and Subtropics

P. Francescatto, D. Pazzin, A. Gazolla Neto, J.C. Fachinello, C.L. Giacobbo

Cydonia, Pyrus, cultivars, grafting, incompatibility, trunk diameter

https://doi.org/10.17660/ActaHortic.2010.872.34