ISHS Acta Horticulturae 383: Mineral Nutrition of Deciduous Fruit Plants
EFFECT OF CANOPY MANIPULATION AND ECOPHYSIOLOGICAL CONDITIONS ON LEAF NUTRITIONAL STATUS, GAS EXCHANGE AND LEAF VITALITY IN GRAPEVINES |
| Authors: | M. Bertamini, J. Tardáguila, F. Campostrini |
| Keywords: | chlorophyll fluorescence, senescence, Vitis vinifera L. |
| Abstract:
Vines of cv. Chardonnay were grown in the field, pruned on two pruning levels (6=PL-1, and 16=PL-2, nodes per vine) and trained on two different systems (Spur-pruned Cordon=SPC, and Simple Curtain=SC). Some vines were partially defoliated removing the seven basal leaves at fruit set. Gas exchanges, chl, fluorescence emission and nutritional status were measured on basal and apical leaves. The N, P and K concentrations were higher in the apical leaves; Ca, Mg, Fe Mn concentration were higher in the basal ones. The N, K and Mn concentration in the SPC was higher than in the SC. The PL-1 increased the leaf N concentration. During the season N and P dropped in opposit to Ca, Mg and Fe, that increased. From anthesis to harvest the Fv/Fp and Rfd fluorescence ratios declined in the 12th leaf. During ripening photosynthesis and transpiration were greater in the 12th leaf than in the 4th leaf in both training systems. The leaf senescence was strongly influenced by canopy management; the leaf removal prolonged the photosynthetic activity, reduced the N drop and increased the Ca level in the remaining leaves. The Ca level was correlated with the increase of transpiration in defoliated vines. The relationship found between photosynthesis and Rfd drop and leaf N concentration drop was likely associated with the decline in concentration of RUBISCO and/or the increase of degradative processes of pigment-protein complexes during leaf aging. These results provided evidence that canopy manipulation can strongly modify physiological activity by affecting microclimatic conditions and the sink-source relationship. It seems clear that the type of canopy management should be taken into account when leaf analysis is used for diagnostic purpose of nutritional status. | |
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