Data/hora: 08/06/2024 02:36:47

Biblioteca(s): 	Embrapa Uva e Vinho.	
Data corrente: 	10/02/2006	
Data da última atualização: 	13/11/2019	
Autoria: 	VALLONE, R. C.; NIJENSOHN, L.; CAVAGNARO, J. B.; MERLO, E. E.; MAFFEI, J. A.	
Título: 	Validation of a simple biological indicator of plant water status to determine irrigation timing of grapevines (Vitis vinifera, L).	
Ano de publicação: 	2004	
Fonte/Imprenta: 	Acta Horticulturae, The Hague, n. 646, p. 77-89, 2004.	
Idioma: 	Inglês	
Conteúdo: 	The ability to manipulate wincgrape quality in response to scasonal water deficits through use of the rclative transpiration index (RTI) was evaluated during two consecutive years in container-grown Shiraz grapevines installed inside a commcrcial vineyard. The RTI (Relative Transpiration Index) assesses water loss from plants expcricncing water deficits relatíve to that from well watered controls and was used as an indicator of the plant water stress and for irrigation timing. The treatments were: TI: no stress, T2: moderatc stress from fruit set to veraíson (FV) and T3: moderate stress from veraíson to harvest (VH). Midday (LWPm) and predawn (LWPp) leaf water potential were also measured. The effects of the treatments on the yield components, vegetative and reproductívc growth and specific phenolic compounds of the berries were determined. There was no significant effect of the trcatmcnt during FV and moderate stress was rcachcd in T3 "ines during VII according to RTI and LWPp -críterla. In T2 and T3 the main shoots showed reduced growth due mainly to a reduction in node number, Shoot growth rate was rcduced by water deflcit by 20 and 30% during FV and VII periods respectivcly, In relation to TI, the pruning weight of T2 and T3 was 43.7% and 49.3% less. No significant differences among treatments were found in the yícld components but the weight loss in ripening berries was more evídcnt in T3. The number of cIusters initiated was not affectcd. No significant differcnces in polyphcnolic content was obscrved among treatmcnts, nor in dcgree of tannins polymerization ? Nevertheless, a relative incrcase in flavonol content was observcd during harvest 2000 due to the effcct of late rcstriction and in harvest 2001 a relative increase in anthocyanins, flavonols, proanthocyanidins and also in flavonol monomers due to modcrate stress during preveraison was obscrved, During the two scasons the RTI behaved as a sensitivo and accurate indicator of the plant water availahility and a sim pIe tool for irrigation timing.	
Palavras-Chave: 	Baga; Transpiração relativa.	
Thesagro: 	Composto Fenólico; Crescimento; Irrigação; Uva; Viticultura.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Uva e Vinho (CNPUV)	
Exemplares: 	CNPUV - (7543-1) - ADD - AP - DD -  -  - 06.00102 - DIS