GRAFT COMPATIBILITY BETWEEN EUROPEAN PEAR CULTIVARS AND EAST MALLING "C" ROOTSTOCK/COMPATIBILIDADE DE ENXERTIA ENTRE CULTIVARES DE PEREIRAS EUROPEIAS E PORTAENXERTOS DE MARMELEIRO EAST MALLING "C"

Graft incompatibility is one of the main factors limiting european pear production in Brazil. At present, there is no clear indication of the best combination(s) of european pear cultivars and quince rootstocks for graft compatibility. The study evaluated the graft compatibility for combinations of european Abbe Fetel, Rocha and Williams pear cultivars grafted onto the EMC quince rootstock. The experiment was performed in a commercial european pear orchard in the Urupema municipality, in State of Santa Catarina, during the 2011/12, 2012/13 and 2013/14 growing seasons. The plant growth variables comprised the section increment (mm) in the trunk diameter in the graft union region of cultivars and rootstocks; difference in the diameter of the graft for cultivars and rootstocks; "translocated" incompatibility; "located" incompatibility and the vascular connection in the graft union region, which was assessed by immersing the bases of the plants in a 0.08% succinic acid solution. There were "located" and "translocated" incompatibility between the european Williams pear cultivar and the EMC rootstock based on the vascular discontinuity in the graft union region, which prevented the translocation of succinic acid stain. Thus, the Williams/EMC combination is considered incompatible and it is not recommended for use in commercial orchards. The Rocha/EMC and Abbe Fetel/EMC are considered partially incompatible combinations and showed good development eight years after planting. Index Terms: compatibility level; located incompatibility; translocated incompatibility; Pyrus communis L. ; vascular union; vigor. A incompatibilidade de enxertia e um dos principais fatores limitantes da producao de peras no Brasil. Ate o presente, nao ha uma indicacao da melhor combinacao de cultivares de pereiras-europeias e porta-enxertos de marmeleiros com compatibilidade de enxertia. O estudo avaliou a compatibilidade de enxertia entre as combinacoes de pereiras europeias Abbe Fetel, Rocha e Williams enxertadas sobre o porta-enxerto de marmeleiro EMC. O experimento foi conduzido em pomar comercial de pereira-europeia no municipio de Urupema, estado de Santa Catarina, durante as estacoes de crescimento de 2011/2012, 2012/2013 e 2013/2014. As variaveis de crescimento de plantas foram: o incremento do diametro do tronco na regiao de uniao do enxerto entre as cultivares e o porta-enxerto (mm); diferenca de diametro do enxerto das cultivares e do porta-enxerto, incompatibilidade "translocad