New OH×F Series and Selection CAV03 Rootstocks for Pyrus Communis L. in Southern Brazil

Productivity and vigour of pear trees are directly influenced by the rootstock, as well as the height and architecture of plants. In Brazil, there are few options for pear tree rootstocks that are satisfactorily adapted to different regions where pears are produced. To help provide information on rootstock options an experimental orchard was planted in southern Brazil in 2017 to evaluate the vegetative performance of rootstock and cultivar combinations in Caxias do Sul city, in the Rio Grande do Sul province. The experimental design was four randomized blocks with 6 treatments composed of a 2x3 factorial arrangement (two cultivars - 'Rocha' and 'Santa Maria' and three rootstocks - OHxF69, OHxF87 and CAV03). Each experimental unit had 3 plants. Variables analysed were: plant height, branch length, total number of growing points (spur, branch and shoot) and compatibility by Perraudine coefficient. According to Perraudine analyses, 'Santa Maria' grafted on CAV03 presented the best affinity in comparison to other combinations, even though it had lower canopy height. 'Rocha' on OHxF69 produced fewer spurs and a greater number of shoots than the other OHxF rootstocks and CAV03. 'Santa Maria' on CAV03 had less total growing points than 'Santa Maria' on OHxF87. 'Rocha' on CAV03 had more growing points than on OHxF69.