ISHS Acta Horticulturae 383: Mineral Nutrition of Deciduous Fruit Plants
DIAGNOSIS OF NITROGEN STATUS IN GRAPEVINE |
| Authors: | F. Giorgessi, S. Zanon |
| Keywords: | arginine, N fertilization rates, N fertilization times, Vitis vinifera |
| Abstract:
Research was carried out from 1990 to 1992 in the province of Udine (North East Italy), in a vineyard on the plain (Pinot b./420 A), trained according to the Casarsa system, with a plantation spacing of 3.1 m x 1.1 m. Our study refers to the method proposed by Kliewer and Cook in 1974, based on establishing the arginine concentration in grape juice or canes, in order to diagnose the nitrogen status of vineyards. It aims at proving if their method is reliable even when nitrogen is broadcast in periods other than pre-bloomtime, recommended by Kliewer and Cook. Experimentation was organized so that nitrogen was broadcast yearly at different doses (0, 100, 200 kg x ha-1) and times (pre-bloom, veraison or both prebloom and veraison) with constant doses of phosphorus and potassium. The nitrogen content was measured in the dormant canes as ug of arginine per gram of dry weight. The results emphasized a good relationship between the arginine concentration in canes and the yield responses when the nitrogen is broadcast in pre-bloomtime, thus confirming that the diagnostic method is a valid one. However, when the nitrogen is broadcast in veraison or in pre-bloom + veraison times, the arginine-yield response relationship does not occur or does not occur as reported above. | |
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