Respuesta fisiológica y agronómica de variedades Gallegas de vid a diferentes prácticas de cultivo: cubiertas vegetales y riego

En Galicia, el régimen cambiante en la distribución temporal de las precipitaciones durante los últimos años, junto al cultivo de variedades excesivamente vigorosas que pueden sufrir desequilibrios entre el desarrollo vegetativo y productivo de la vid, han llevado a la realización de este trabajo. El presente estudio tiene como objetivo profundizar en el conocimiento de dos técnicas de manejo del viñedo: el riego y el mantenimiento del suelo mediante cubiertas vegetales, evaluando los efectos que producen en la respuesta fisiológica, agronómica y cualitativa de variedades de vid de cultivo tradicional en Galicia. Los ensayos se realizaron entre los años 2012 y 2014 en tres denominaciones de origen (DO) gallegas: Rías Baixas, Ribeiro y Valdeorras. En todas ellas se planteó un experimento de riego en variedades blancas (Albariño, Godello y Treixadura) y, además, en Ribeiro se instaló un ensayo de manejo del suelo con cubiertas vegetales en una variedad tinta (Mencía). El experimento en la DO Rías Baixas se llevó a cabo en una finca comercial de O Rosal (Pontevedra) dentro de la Subzona Rosal, y consistió en un secano y un riego por goteo aéreo según el criterio empleado habitualmente por la bodega. En esta experiencia, la variedad estudiada fue Albariño. En la DO Ribeiro, el ensayo tuvo lugar en Leiro (Ourense) dentro de la finca experimental de la Estación de Viticultura y Enología de Galicia (EVEGA). Se diseñó un ensayo consistente en un secano y un riego por goteo aéreo al 50% de la evapotranspiración del cultivo (ETc). En este caso se estudiaron las variedades Godello y Treixadura. Dentro de la DO Valdeorras, la situada más al interior de Galicia, la parcela de estudio estuvo situada en una finca comercial de la localidad de A Rúa (Ourense). Este experimento consistió en tres tratamientos: un secano, un riego por goteo aéreo y un riego por goteo enterrado a 40 cm. Se aplicó, desde floración, un riego diario de una hora con un gotero de 2 L h-1 por planta. La variedad objeto de estudio, en este caso, fue Godello. La experiencia sobre manejo del suelo mediante cubiertas vegetales se instaló en la finca experimental de EVEGA dentro de la DO Ribeiro, y contó con cuatro tratamientos en las calles: laboreo, cubierta espontánea, Raigrás (Lolium perenne L.) y Trébol (Trifolium subterraneum L.). La variedad estudiada fue Mencía. Se realizaron medidas ecofisiológicas en la planta (potencial hídrico foliar a mediodía, de mañana y de tallo, conductancia estomática, actividad del fotosistema II, contenido relativo en clorofila), contenido en agua del suelo, parámetros agronómicos (fenología, área foliar, producción, madera de poda) y de calidad de mostos y vinos (acidez total, pH, sólidos solubles y grado alcohólico, ácidos málico y tartárico) procedentes de los diferentes ensayos. Los vinos fueron catados por consumidores (50 participantes por año) para determinar la preferencia de estos por los vinos de alguno de los distintos tratamientos estudiados. En general, en los tratamientos de riego se observaron potenciales hídricos menos negativos que en los de secano que, por su parte, no alcanzaron niveles de estrés ya que no se vieron comprometidos ni la producción ni los parámetros fisiológicos. En cuanto a los parámetros de mostos y vinos, se observó un aumento en el contenido en sólidos solubles y el grado alcohólico respectivamente, así como un descenso de la acidez en los tratamientos de secano con respecto a los de riego. Si bien, en la mayoría de los casos, estas diferencias no han sido significativas. Respecto a los resultados de las catas de consumidores, se observó una ligera preferencia hacia los vinos procedentes de los tratamientos de secano en las DO Ribeiro y Valdeorras, mientras que en Rías Baixas los vinos de los dos tratamientos considerados fueron valorados de manera muy similar. En cuanto al experimento de cubiertas vegetales, se observaron diferencias significativas entre tratamientos en el potencial hídrico de tallo para algunas fechas de medida. Se apreció un estrés hídrico moderado, siendo los potenciales más negativos los correspondientes a las cepas bajo tratamiento de cubierta espontánea. Se produjo un ligero descenso, no significativo, en la producción bajo los tratamientos con cubierta vegetal y, lo más interesante, un descenso significativo en el tamaño de baya, lo que mejora la relación pulpa/hollejo. Además, en el tercer año de ensayos se observó un descenso en la superficie foliar y madera de poda en las cepas bajo cubiertas frente a las del testigo con suelo labrado. No se observaron diferencias significativas en los parámetros de mostos y vinos entre los distintos tratamientos y años estudiados. Asimismo, los consumidores fueron capaces de apreciar diferencias entre tratamientos y mostraron una ligera preferencia por los vinos provenientes de los tratamientos bajo cubierta. En resumen, los parámetros productivos apenas se han visto afectados por los tratamientos de riego mientras que el crecimiento vegetativo de las cepas se ha visto reducido por el uso de cubiertas vegetales. En cuanto a los parámetros de calidad de mostos y vinos, aunque las diferencias no han sido significativas en la mayoría de los casos, se observa una tendencia a obtener una menor graduación alcohólica y una mayor acidez bajo los tratamientos de riego en todas las DO consideradas en el presente estudio

Monitoring of emerging water stress situations by thermal and vegetation indices in different almond cultivars

In recent years, the area dedicated to modern irrigated almond plantations has increased significantly in Spain. However, the legal irrigation allocations are lower than the maximum water requirements of the crop in most cases. Therefore, almond growers are forced to implement regulated deficit irrigation strategies on their farms, applying water stress in certain resistant phenological periods and avoiding it in sensitive periods. Given the need to monitor the water status of the crop, especially in the most sensitive periods to water stress, the objective of this work was to evaluate the sensitivity of two UAV-based crop water status indicators to detect early water stress conditions in four almond cultivars. The field trial was conducted during 2020 in an experimental almond orchard, where two irrigation strategies were established: full irrigation (FI), which received 100% of irrigation requirements (IR), and regulated deficit irrigation (RDI), which received 70% of IR during the whole irrigation period except during the kernel-filling stage when received 40% IR. The UAV flights were performed on four selected dates of the irrigation season. The Crop Water Status Index (CWSI) and the Normalized Difference Vegetation Index (NDVI) were derived from thermal and multispectral images, respectively, and compared to classical water status indicators, i.e., stem water potential (Ψstem ), stomatal conductance (gs ), and photosynthetic rate (AN ). Of the four flights performed, three corresponded to mild water stress conditions and a single flight was performed under moderate water stress conditions. Under mild water stress, CWSI was not able to capture the differences between FI and RDI trees that were observed with Ψstem . Under moderate stress conditions, CWSI was sensitive to the water deficit reached in the trees and showed significant differences among both irrigation treatments. No differences were observed in the CWSI and NVDI response to water stress among cultivars. Although NDVI and CWSI were sensitive to water stress, the low signal intensity observed in NDVI makes this index less robust than CWSI to monitor crop water stress. It can be concluded that UAV-based CWSI measurements are reliable to monitor almond water status, although for early (mild) levels of water stress, Ψstem seems to be the preferred option.Junta de Andalucía AVA.AVA2019.05

Efeitos da rega superficial e subsuperficial sobre a fisiologia e produção da variedade ‘Godello’ na Galiza, Noroeste de Espanha

Irrigation has been considered a controversial practice in European traditional viticulture due to potential alterations in the balance between vegetative growth and yield. In this regard, the influence of surface (DI) and subsurface (SDI) drip irrigation on physiological performance of the ‘Godello’ grapevine (Vitis vinifera L.) cultivar was compared with a non-irrigated control (R) over three consecutive growing seasons (2012- 2014) in NW Spain. Irrigation improved vine water status; R plants reached a minimum of midday leaf water potential of –1.5 MPa, whereas DI and SDI plants reached –1.3 MPa. Stomatal conductance was unaffected by irrigation as well as chlorophyll a fluorescence. However, photosynthetic pigments were present at higher concentrations in leaves from irrigated plants than in those from R plants in 2013. In addition, R plants showed higher values for the indicators of oxidative damage. No significant yield improvements were observed for irrigated plants, although the trend was to obtain slightly higher yields under irrigation in years with low rainfall amounts. This may not encourage growers to establish irrigation systems on their vineyards. However, these results may be important with the objectives of stabilizing yield from year to yearA rega tem sido considerada uma prática controversa na viticultura tradicional Europeia devido a potenciais alterações no equilíbrio entre crescimento vegetativo e rendimento. A este respeito, a influência da irrigação por gotejamento superficial (DI) e subsuperficial (SDI) sobre o desempenho fisiológico da variedade ‘Godello’ (Vitis vinifera L.) foi comparada com uma testemunha em condições de sequeiro (R) ao longo de três anos consecutivos (2012-2014) no noroeste de Espanha. A rega melhorou o estado hídrico da videira; as plantas do tratamento R atingiram potenciais hídricos foliares ao meio-dia de –1.5 MPa, comparativamente a um valor de –1.3 MPa para as plantas dos tratamentos DI e SDI. A conductância estomática e a fluorescência da clorofila a não foram afectadas pela rega. No entanto, os pigmentos fotossintéticos apresentaram maiores concentrações em folhas de plantas regadas quando se comparam com as plantas do tratamento R em 2013. Além disso, as plantas do tratamento R apresentaram valores superiores para os indicadores de danos oxidativos. Não foi detectado nenhum incremento do rendimento nas plantas regadas, embora se tenha observado uma tendência para obtenção de rendimentos ligeiramente mais elevados sob rega em anos com baixa pluviosidade. Tal poderá não encorajar aos viticultores a implementar sistemas de rega nas suas vinhas. No entanto, estes resultados podem ser importantes para a estabilização do rendimento de ano para anoThis research was supported by the Spanish Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Project nº RTA2011-00041-C02-00, with 80% FEDER funds. J.M. Mirás-Avalos and E.M. Martínez thank Xunta de Galicia for funding their contracts through the “Isidro Parga Pondal” and “Isabel Barreto” Programmes. E. Trigo-Córdoba thanks INIA for their PhD scholarship (FPI-INIA)S

Does predawn water potential discern between irrigation treatments in Galician white grapevine cultivars?

Aims: To evaluate the usefulness of predawn water potential (Ψpd) to assess the water status of Galician grapevine cultivars for irrigation purposes. Methods and results: Three Galician white grapevine cultivars (Albariño, Godello and Treixadura) were subjected to rain-fed and irrigation conditions during the 2013 growing season. Diurnal changes in leaf water potential (Ψl) were measured using a pressure chamber on days with high evapotranspiration demand. Stem water potential (Ψs) was measured at midday. Ψpd was not able to discriminate between treatments, whereas Ψl and Ψs at midday were able to detect significant differences in water status among plants. Conclusion: Ψpd was not useful to evaluate vine water status under the Galician climatic conditions. In contrast, both Ψl and Ψs were effective for detecting differences between treatments and can thus be used for irrigation management purposes. Significance and impact of the study: This is the first study evaluating water status of Galician grapevine cultivars. It also provides useful information about the strategy for its control through measurements of midday Ψl or Ψs

Amino acid profiles to differentiate white wines from three autochtonous Galician varieties

Amino acids play a relevant role in wine quality and can allow for classifying wines according to the variety. In this work, the amino acid contents of Albariño, Godello, and Treixadura wines, three autochthonous varieties from Galicia (NW Spain), were determined. During three consecutive vintages, these varieties were grown on the same vineyard and were harvested at optimum maturity, and the wines were elaborated following the same enological protocol. The identification and quantification of the primary amino acids were carried out by high-performance liquid chromatography with photodiode array detection, after a derivatization. Amino acid contents in these white varieties were within the range of values reported for other European wines, but Treixadura wines showed the highest concentrations, while wines from the Albariño variety showed the lowest contents. Apart from proline, whose concentrations were caused by yeast release, the most abundant amino acids were aspartic acid, glutamic acid, lysine, arginine, asparagine, alanine, and histidine. Principal component analysis separated wines by variety according to their amino acid contents.Instituto Nacional de Tecnología Agraria y Alimentaria | Ref. RTA2011-00041-C02-01Xunta de GaliciaEuropean Commissio

Response of grapevine cv. ‘Brancellao’ and ‘Sousón’ to supplementary irrigation: Water relations, vine growth, yield and berry and wine composition

Growers are concerned about the negative impacts on vine yield and berry quality caused by global warming. Irrigation systems are increasingly being installed in vineyards in order to counteract those problems. Therefore, an efficient irrigation management is required. In this context, a field experiment was carried out over three years (2012-2014) on red Vitis vinifera (L.) cv. ‘Brancellao’ and ‘Sousón’ in order to assess the effects of supplementary irrigation on vine performance and must and wine composition. Rain-fed vines were compared with a treatment irrigated to 40% of potential evapotranspiration (ET0) from bloom to two/three weeks before harvest. Both cultivars showed less negative stem water potentials under irrigation than under rain-fed conditions; however, stomatal conductance was similar between treatments. Yield was unaffected by irrigation, whereas pruning weight tended to increase in both cultivars. Must and wine composition, including amino acids and volatile compound concentrations, were mostly unaffected by irrigation. Water productivity was higher under rain-fed conditions and, as a consequence, gross incomes were not increased by irrigation. Therefore, irrigation does not seem an economically viable agricultural practice under the conditions of this trial

Irrigation effects on the sensory perception of wines from three white grapevine cultivars traditional from Galicia (Albariño, Godello and Treixadura)

This study aimed to assess the effect of irrigation on the sensory profile of wines from three Galician white grapevine cultivars. Field experiments were carried out in 2011 and 2012 at the research farm of the Estación de Viticultura e Enoloxía de Galicia (EVEGA), where two treatments were imposed: rain-fed and irrigation to the 50% of potential evapotranspiration. A panel of seven judges tasted the wines in six sessions (one per cultivar and year) for evaluating their sensory profile. In the case of ‘Albariño’, three descriptors, although not the same for both years, were significantly different between treatments. For ‘Godello’, several descriptors differed between treatments, and citric was present in both years. In ‘Treixadura’ white fruit and persistence were present in 2011 and 2012. Several descriptors contributed to the hedonic index, but differed between wines; however, balance was common for all the cultivars and years. In conclusion, ‘Albariño’ and ‘Godello’ wines from the rain-fed treatment received higher marks than those from the irrigation treatment; whereas Treixadura wines from the irrigation treatment were better valued

Irrigation effects on the performance of grapevine (<em>Vitis vinifera</em> L.) cv. ‘Albariño’ under the humid climate of Galicia

Aims: Vine-growers worldwide are concerned about climate change effects on grape yield and quality. Drip irrigation systems are increasingly being installed even in humid regions such as Galicia (NW Spain). In this context, a field experiment was carried out over three seasons (2012-2014) on white Vitis vinifera L. cv. ‘Albariño’ to assess the effects of deficit irrigation on vine physiology, yield and must and wine composition. Methods and results: Rain-fed vines were compared with a treatment irrigated to 50% of the estimated crop evapotranspiration (ETc) from bloom to two weeks before harvest. Irrigated vines showed more positive stem water potentials than those rain-fed. Yield was unaffected by irrigation except in 2014 (19% increase). Pruning weight was increased by irrigation. Must soluble solids tended to decrease and total acidity to increase with irrigation; however, wines were similar between treatments. Water productivity was slightly higher under rain-fed conditions. Conclusion: Under the conditions of this experiment, irrigation was of no interest either in terms of grape and wine quality or in terms of net income. Significance and impact of the study: These results may be useful for managing water resources in vineyards under similar climate conditions

Influence of Soil Management on the Red Grapevine (Vitis vinifera L.) Mencía Must Amino Acid Composition and Wine Volatile and Sensory Profiles in a Humid Region

Adopting cover crops for vineyard soil management can provide several benefits, including soil protection, reductions in vine vigor, and enhancements in berry composition. However, the effects of this practice on wine aroma have seldom been addressed. This study aimed to determine the influence of different cover crops and soil tillage on the must and wine amino acid composition and wine volatile compounds of the red cultivar, &lsquo;Menc&iacute;a&rsquo; (Vitis vinifera L.), grown in Northwest Spain. Treatments consisted of soil tillage (ST), native vegetation (NV), English ryegrass (ER), and subterranean clover (SC). Cover crops did not alter the macro-constituents of musts; however, musts from NV and SC tended to lower concentrations of amino acids. Some color attributes of wines were influenced by cover crops in the vineyard. Methanol and trans-linalool oxide (pyran) concentrations in wines were significantly affected by soil management. Professional tasters encountered differences in visual, aroma, and palate descriptors of wines depending on the treatment imposed in the vineyard. These alterations in sensory properties seemed to obey to slight modifications of wine chemical characteristics due to vineyard soil management. According to these results, cover crops might be useful for modulating wine aroma in humid climates

Effects of Two Different Irrigation Systems on the Amino Acid Concentrations, Volatile Composition and Sensory Profiles of Godello Musts and Wines

The concentrations of amino acids and volatile compounds of a given grapevine cultivar may be modified by climate variability between years and by management practices, such as irrigation, that may alter the typicality of its wines. The current study aimed at assessing the amino acid profile of musts and wines, volatile composition and sensory profile of wines from Vitis vinifera (L.) cultivar Godello under rain-fed and two drip irrigation systems (above, drip irrigation (DI), and under the soil surface, subsurface drip irrigation (SDI)) over three consecutive years. Irrigation tended to increase must and wine total acidity; however, it did not alter must amino acid concentrations significantly. Irrigation reduced the concentrations of acetaldehyde and methanol in Godello wines. Moreover, irrigation tended to decrease the concentrations of compounds giving fruity aromas, such as acetaldehyde (by 31% in SDI) and isoamyl acetate (by 21% in SDI), when compared to rain-fed conditions. Sensory analysis revealed slight differences between treatments. Rain-fed and SDI were the treatments showing the greatest differences. Weather conditions affected more must and wine composition than in-season effects caused by irrigation