Estimating Seasonal Changes in The Quantity of White Unsuberized Root on Fruit Trees

Root production and mortality under elevated atmospheric carbon dioxide

“…Norby (1994) stated that "the mean residence time of live fine roots generaUy is about 1 year... ", contrasting markedly with the very short half-lives seen under grassland. However, there are numerous records of short-lived roots on woody plants: median lifespan of summer-produced roots under apple (Malus domestica) was 14-21 days (Head, 1966) and under citrus (Citrus volkameriana and C. jambhiri) was from 16-51 days (Kosola et al, 1995). Pregitzer and co-workers have provided demographic data for tree roots both under elevated CO2 and in relation to a climatic gradient, allowing estimates of t 1/2 of between 107 and 268 d. Under the grassland we studied in the field, only cohorts of roots produced in autumn have half-lives comparable with these, and typical summer cohorts have t 1/2 between 10 and 30 d (Fitter et al, unpubl, data), consistent with earlier estimates by Garwood (1957), and Troughton (1981).…”

Elements of the responses of apple trees to root pruning – a review

“…Veränderungen bei einer dieser Komponenten bewirken Veränderungen auch bei den anderen. Dabei besteht die Tendenz, ein gewisses Gleichgewicht herzustellen und beizubehalten, das für eine bestimmte Sorten-/Unterlagen-Kombination an einem bestimmten Standort und für ein bestimmtes phänologisches Stadium der Pflanze typisch ist (Sachs 2005 Head 1966;1967;1969a;Lyr u. Hoffmann 1967;Cripps 1970;1971;Atkinson u. Wilson 1980;Psarras et al 2000;Eissenstat et al 2006;Yao et al 2006). Annahmen über autonome Wachstumsrhythmen von Baumwurzeln haben sich dabei nicht bestätigt (Persson 2002).…”

Root Methods

“…Root windows allowed the study of in situ root growth periodicity in perennial plant species, for example in fruit trees (Head 1966), forest trees (McDougallI916), shrubs and bushes (Fordham 1972;Fernandez and Caldwell 1975), in grassland plant communities (Speidel and Weiss 1974;Hayes and Seastedt 1987) or in crop plants (Pearson and Lund 1968). In most early experiments, glass plates were installed against vertical soil profiles.…”