Effect of Postharvest Defoliation on Carbon and Nitrogen Resources of High-Yielding Sauvignon blanc Grapevines
| Autor: | J.S. Bennett, Helen L. Boldingh, Marc Greven, Sue Neal, D. Stuart Tustin, Maria Carmo Vasconcelos |
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| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
Canopy Vine Vegetative reproduction food and beverages chemistry.chemical_element Growing season 04 agricultural and veterinary sciences Horticulture Biology 01 natural sciences Nitrogen 040501 horticulture chemistry Agronomy Shoot Postharvest 0405 other agricultural sciences 010606 plant biology & botany Food Science Annual percentage yield |
| Zdroj: | American Journal of Enology and Viticulture. 67:315-326 |
| ISSN: | 0002-9254 |
| DOI: | 10.5344/ajev.2016.15081 |
| Popis: | We quantified the importance of postharvest carbohydrate assimilation and nitrogen availability to replenish vine reserves, over and above maintaining optimal growth, productivity, and fruit quality of high-yielding, vigorous Sauvignon blanc grapevines. To create different carbohydrate (CHO) and nitrogen (N) reserve concentrations, our factorial-design trial consisted of a postharvest defoliation treatment overlaid with a pruning treatment in which 48 or 72 nodes were retained on four- or six-cane vertical shoot positioned vines, respectively. In defoliation (Defol) vines, all leaves were removed immediately after fruit harvest, while foliated vines (Fol) went through normal senescence. From just after ectodormancy in 2008, samples of root and trunk tissue were taken throughout the years for CHO and N analyses and results were compared with annual yield data. Both defoliation and node number treatments reduced vine growth and yield. Additionally, differences in CHO and N of the permanent structure were found. Depleted winter reserves in trunk and root were replenished during the next growth cycle, suggesting that grapevine N and CHO partitioning favor survival of the permanent structure over increasing vine size and yield. However, after two consecutive years of defoliation, the cumulative effects of smaller, less fruitful canes from year one and reduced carbohydrates from the subsequent year reduced both yield and vegetative growth in the third growing season. Therefore, even the short-lived postharvest canopy in cool climates contributes to the vine CHO economy. Defoliation or excessive crop loads affected carbohydrate reserves in vines, but only after several consecutive years of low recharge; this manifested iteself in lower yields and poorer vegetative growth. |
| Databáze: | OpenAIRE |
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