title: Growth patterns and morphology of fine roots of size-controlling and invigorating peach rootstocks.
abstract: We compared growth patterns and morphology of fine roots of size-controlling and invigorating peach (Prunus persica (L.) Batsch) rootstocks. Peach trees were grafted on five rootstocks: a vigorous control (Nemaguard), three intermediate vigor rootstocks (K119-50, P30-135 and Hiawatha), and a semi-dwarfing rootstock (K146-43). Minirhizotron tubes were installed at the base of trees on each rootstock and root images captured with a minirhizotron digital camera system. Number, visible length, and diameter of new roots were recorded at fixed soil depths from April 19, 2000 to December 19, 2001. Root diameter, specific root length, root tissue density and root length density were also measured periodically for each rootstock on roots collected from in-growth cores. Rootstocks had similar seasonal patterns of new root production. Fine root production was lowest in winter and appeared to decline during the final stages of fruit growth. A rootstock with almond in its genetic background (K119-50) produced the greatest quantity of fine roots and had the greatest number of new roots below 69 cm, whereas there were no differences among the other four rootstocks in the total number of roots produced. Rootstock K146-43 had thicker fine roots than the other rootstocks. Independent of rootstock, fine roots produced during spring had greater specific root length than those produced later in the season. The seasonal pattern of fine root production did not appear to be associated with the previously reported effects of these dwarfing rootstocks on shoot growth and stem water potential early in the growing season.
authors.affiliation: Dipartimento di Arboricoltura, Botanica e Patologia Vegetale, Università degli Studi di Napoli Federico II, Via Università 100, 80055 Portici, Napoli, Italy.
authors.forename: Boris
authors.initials: B
authors.lastname: Basile
authors.forename: David R
authors.initials: DR
authors.lastname: Bryla
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Salsman
authors.forename: Jordi
authors.initials: J
authors.lastname: Marsal
authors.forename: Chiara
authors.initials: C
authors.lastname: Cirillo
authors.forename: R Scott
authors.initials: RS
authors.lastname: Johnson
authors.forename: Theodore M
authors.initials: TM
authors.lastname: Dejong
mesh_terms: D018517:Plant Roots / Q000033:anatomy & histology / Q000254:growth & development*; D027861:Prunus / Q000033:anatomy & histology / Q000254:growth & development*; D012621:Seasons; D012987:Soil
chemical_list: D012987:Soil