Performance of field-selected clones of Pera sweet orange in Northern São Paulo state, Brazil

Abstract

Brazil is the world's largest sweet orange producer, with Pera sweet orange [Citrus sinensis (L.) Osbeck] as the main cultivar and Pera IAC as the most planted clone, due to its good overall horticultural performance and because the plants are preimmunized with the attenuated and protective PIAC isolate of the citrus tristeza virus (CTV). Field-selected elite Pera sweet orange trees selected in Bebedouro, on Northern São Paulo state, were previously submitted to shoot tip grafting and preimmunized against CTV. Thirteen of these clones were evaluated in the present study comparatively with the Pera IAC and the Pera Olímpia clones in a trial set up in 1998 under rain-fed conditions in Bebedouro. All the scions were grafted onto Rangpur lime (C. limonia Osbeck) rootstock. The experiment was conducted following a completely randomized design, with 15 treatments (clones), six replications and one plant in the plot. Stem pitting severity, plant growth, fruit yield and quality were evaluated. As Pera IAC and Pera Olímpia, the thirteen pre-immunized clones did not develop stem pitting symptoms characteristics of Pera reaction to CTV. The Pera clones Milton Teixeira, Fazenda União-35 Anos and Alexandre Maróstica-1949 had similar fruit yield, production efficiency and total soluble solids content in the juice than the Pera IAC standard variety, yet they showed remarkably later fruit maturation. Index terms: Citrus sinensis, fruit yield and quality, CTV, cross protection. Desempenho de clones selecionados em campo de laranjaPera no norte do Estado São Paulo, Brasil RESUMO O Brasil é o principal produtor de laranjas do mundo. A laranja Pera [Citrus sinensis (L.) Osbeck] é a principal variedade de laranja cultivada no Brasil, sendo o clone IAC o mais importante, por ser pré-imunizado com a estirpe fraca e protetiva PIAC do vírus da tristeza dos citros, entre outras boas características. Plantas elite de laranja Pera selecionadas em campo na região de Stuchi et al.