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Article III. Dynamics of non-structural carbohydrate reserves in pruned leguminous trees

by Chesney, Patrick E; Vaast, Philippe (autor/a); Schlöenvoigt, Andrea (autor/a); Kass, Donald (autor/a); Vlek, Paul (autor/a); Murach, Dieter (autor/a).
Type: materialTypeLabelArticleDescription: 27 páginas.Subject(s): PODA | RAICES | ARBOLES | ARBOLES FIJADORES DEL NITROGENO | TROPICOS HUMEDOS | ECOLOGIA FORESTAL | BOSQUE TROPICAL HUMEDO | ERYTHRINA POEPPIGIANA | CULTIVO EN CALLEJONES | CARBOHIDRATOS | ALMIDON | ESPECIES | SILVICULTURA | TURRIALBA | COSTA RICAOnline Resources: Texto completo (En) | http://hdl.handle.net/11554/8905 In: Pruning effects on roots of nitrogen fixing trees in the humid tropicsSummary: In alley cropping, fast growing leguminous trees are pruned to reduce competition with crops for light and to provide organic inputs for crop nutrition. Tree regrowth depends on non-structural carbohydrate reserves in the remaining tree parts. In this study, starch and soluble carbohydrate dynamics in roots and stems of unpruned, completely pruned (all shoots removed) and partially pruned (one branch retained on the pruned stump) Erythrina poeppigiana and Gliricidia sepiul/l trees were studied under humid tropical conditions in Turrialba, Costa Rica. Measurements were made at O, 2, 6 and 12 weeks afier pruning (W AP) during both wet and dry periods. In general, starch concentration was highest in unpruned trees. Starch concentration in roots was higher than that in stems. During early regrowth, the effect of pruning intensity was first observed in stems and starch reserves were more depleted in stems than in roots, a process more evident during the dry periodo. The critical tree regrowth stage for starch mobilisation was that of vigorous sprout development at 6 W AP particularly in completely pruned trees. If the proportion of sugar to starch concentration is taken as an indicator of metabolic activity then there was greater metabolic activity in stems than in roots of E. poeppigiana. Metabolic activity was high in both stems and roots of G. sepiulIl. Starch re-synthesis in roots occurred at 12 W AP in G. '1epiul/l, and later than 12 W AP in E. poeppigiana roots. The implication fOl' tree management would be lo extend the regrowth period beyond 12 weeks to facilitate shoo! growth with less root competition fOl' fixed C in the former, and for acropetal movement of non-structural carbohydrates to replenish root sto res in the latter.
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Artículo de tesis (Doctorado) - CATIE, Turrialba (Costa Rica), 2000

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In alley cropping, fast growing leguminous trees are pruned to reduce competition with crops for light and to provide organic inputs for crop nutrition. Tree regrowth depends on non-structural carbohydrate reserves in the remaining tree parts. In this study, starch and soluble carbohydrate dynamics in roots and stems of unpruned, completely pruned (all shoots removed) and partially pruned (one branch retained on the pruned stump) Erythrina poeppigiana and Gliricidia sepiul/l trees were studied under humid tropical conditions in Turrialba, Costa Rica. Measurements were made at O, 2, 6 and 12 weeks afier pruning
(W AP) during both wet and dry periods. In general, starch concentration was highest in unpruned trees. Starch concentration in roots was higher than that in stems. During early regrowth, the effect of pruning intensity was first observed in stems and starch reserves were more depleted in stems than in roots, a process more evident during the dry periodo. The critical tree regrowth stage for starch mobilisation was that of vigorous sprout development at 6 W AP particularly in completely pruned trees. If the proportion of sugar to starch concentration is taken as an indicator of metabolic activity then there was greater metabolic activity in stems than in roots of E. poeppigiana. Metabolic activity was high in both stems and roots of G. sepiulIl. Starch re-synthesis in roots occurred at 12 W AP in G. '1epiul/l, and later than 12 W AP in E. poeppigiana roots. The implication fOl' tree management would be lo extend the regrowth period beyond 12 weeks to facilitate shoo! growth with less root competition fOl' fixed C in the former, and for acropetal movement of non-structural carbohydrates to replenish root sto res in the latter.

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