Field studies on citrus roots are important for genetic selection of cultivars and for management practices such as localized irrigation and fertilization. To characterize root systems of six rootstocks, taking into consideration chemical and physical characteristics of a clayey Typic Hapludox of the Northern State of Paraná, this study was performed having as scion the 'IAC-5 Tahiti' lime [Citrus latifolia (Yu. Tanaka)]. The rootstocks 'Rangpur' lime (C. limonia Osbeck), 'Africa Rough' lemon (C. jambhiri Lush.), 'Sunki' mandarin [C. sunki (Hayata) hort. ex Tan.], Poncirus trifoliata (L.) Raf., 'C13' citrange [C. sinensis (L.) Osb. x P. trifoliata (L.) Raf] and 'Catânia 2' Volkamer lemon (C. volkameriana Ten. & Pasq.) were used applying the trench profile method and the SIARCS® 3.0 software to determine root distribution. 'C-13' citrange had the largest root system. 'Volkamer' lemon and 'Africa Rough' lemon presented the smallest amount of roots. The effective depth for 80 % of roots was 31-53 cm in rows and 67-68 cm in inter-rows. The effective distance of 80 % of roots measured from the tree trunk exceeded the tree canopy for P. trifoliata, 'Sunki' mandarin, and 'Volkamer' and 'Africa Rough' lemons.
Citrus latifolia; root system; trench profile method; soil bulk density