Articles
THE INTERACTION BETWEEN NITROGEN AND SHADE ON GRAPEVINE: THE EFFECTS ON NUTRITIONAL STATUS, LEAF AGE AND LEAF GAS EXCHANGES
Article number
564_29
Pages
253 – 260
Language
English
Abstract
In a factorial experimental layout, several Chardonnay vines were fertilized with 25 and 100 kg of nitrogen/hectare (N/ha) and tested by two different light regimes (full sun and 50% light reduction), in 1997 and 1998. In 1999 the same vines were used to study the residual N and shading effects.
During 1997 and 1998, shoot growth was measured weekly throughout the growing season, whereas leaf gas exchange was measured on leaves of different age ( 75 days from unfolding) three times a day (9.00, 13.00 and 16.00) at pre bloom, full bloom, fruit-set, pea size, bunch closure, veraison, and harvest.
At the end of each measurement day same tested leaves were sampled for the determination of their greenness, dry matter and mineral nutritional status.
In 1997 and 1998, dry matter and mineral concentration were measured on each aerial vine organ at harvest time, while in 1999 measurement was carried out only on leaves.
For the same vines, quantitative (n° of cane/vine, n° of cluster/vine, bud fertility, yield, cluster weight, and n° of berries/cluster) and qualitative (°Brix, titratable acidity, pH, malic acid, tartaric acid, and potassium in juice) fruit data were collected.
Shaded vines produced 50% less dry matter than control ones, even though shoot growth was higher.
Despite the high N concentration in leaves of shaded vines, net photosynthesis (Pn), averaged over the three sampling time during the day, was always lower in these vines than in the control ones.
This difference was statistically significant for young and mature leaves before fruit-set and from veraison until harvest.
N did not significantly affect the tested parameters, neither those regarding vigor, yield and quality of berries nor those related to photosynthetic activity of leaves.
N affected only the proportion of plant aerial organs, whereas light changed also their mineral concentration.
During 1997 and 1998, shoot growth was measured weekly throughout the growing season, whereas leaf gas exchange was measured on leaves of different age ( 75 days from unfolding) three times a day (9.00, 13.00 and 16.00) at pre bloom, full bloom, fruit-set, pea size, bunch closure, veraison, and harvest.
At the end of each measurement day same tested leaves were sampled for the determination of their greenness, dry matter and mineral nutritional status.
In 1997 and 1998, dry matter and mineral concentration were measured on each aerial vine organ at harvest time, while in 1999 measurement was carried out only on leaves.
For the same vines, quantitative (n° of cane/vine, n° of cluster/vine, bud fertility, yield, cluster weight, and n° of berries/cluster) and qualitative (°Brix, titratable acidity, pH, malic acid, tartaric acid, and potassium in juice) fruit data were collected.
Shaded vines produced 50% less dry matter than control ones, even though shoot growth was higher.
Despite the high N concentration in leaves of shaded vines, net photosynthesis (Pn), averaged over the three sampling time during the day, was always lower in these vines than in the control ones.
This difference was statistically significant for young and mature leaves before fruit-set and from veraison until harvest.
N did not significantly affect the tested parameters, neither those regarding vigor, yield and quality of berries nor those related to photosynthetic activity of leaves.
N affected only the proportion of plant aerial organs, whereas light changed also their mineral concentration.
Authors
D. Porro, M. Dallaserra, A. Zatelli, A. Ceschini
Keywords
dry matter production, leaf age, leaf gas exchanges, light availability, grapevine, nitrogen, partitioning, photosynthetic activity, shade
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