Root distribution, vigor and productivity of European pear grafted on quince rootstocks

The aim of this study was to characterize the root system distribution throughout the soil profile with different combinations of European pear cultivars and quince rootstocks and the relationship to the plant vegetative and productive aspects. The experiment was conducted at the Agrícola Fraiburgo S/A company experimental area, located at Urupema-SC, southern Brazil, during the 2011/12, 12/13 and 13/14 seasons. The planting density was 2500 trees ha^-1 and the combinations evaluated were: ‘Abbé Fétel’/‘Adams’, ‘Clapp’s Favourite’/‘EMA’, ‘Santa Maria’/‘Adams’, ‘Rocha’/‘Adams’, ‘Doyenne du Comice’/‘Adams’ and ‘Packham’s Triumph’/‘EMA’. ‘Abbé Fétel’ grafted on ‘Adams’ quince induced greater root growth and explored a larger volume of soil, higher vegetative growth in plant height, canopy volume, trunk diameter increment of the scion and rootstock, total cumulative fresh mass, as well as reduced productivity. ‘Clapp’s Favourite’/‘EMA’ resulted in a lower concentration of roots, exploring a smaller volume of soil in relation to other evaluated combinations, was less vigorous and gave low productivity. The root growth of the combinations ‘Santa Maria’/‘Adams’ and ‘Rocha’/‘Adams’ was considered intermediate in relation to other combinations and resulted in higher productivity.