Open Access
Terahertz time domain spectroscopy allows contactless monitoring of grapevine water status
(Frontiers Media, 2015) Santesteban García, Gonzaga; Palacios Horcajada, Inés; Miranda Jiménez, Carlos; Iriarte Galarregui, Juan Carlos; Royo Díaz, José Bernardo; Gonzalo García, Ramón; Producción Agraria; Nekazaritza Ekoizpena; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua, IIM14244.RI1
Agriculture is the sector with the greatest water consumption, since food production is frequently based on crop irrigation. Proper irrigation management requires reliable information on plant water status, but all the plant-based methods to determine it suffer from several inconveniences, mainly caused by the necessity of destructive sampling or of alteration of the plant organ due to contact installation. The aim of this work is to test if terahertz (THz) time domain reflectance measurements made on the grapevine trunk allows contactless monitoring of plant status. The experiments were performed on a potted 14-years-old plant, using a general purpose THz emitter receiver head. Trunk THz time-domain reflection signal proved to be very sensitive to changes in plant water availability, as its pattern follows the trend of soil water content and trunk growth variations. Therefore, it could be used to contactless monitor plant water status. Apart from that, THz reflection signal was observed to respond to light conditions which, according to a specifically designed girdling experiment, was caused by changes in the phloem. This latter results opens a promising field of research for contactless monitoring of phloem activity.
Open Access
Cover crops in viticulture. A systematic review (2): Implications on vineyard agronomic performance
(International Viticulture and Enology Society (IVES), 2021) Abad Zamora, Francisco Javier; Hermoso de Mendoza, Irantzu; Marín Ederra, Diana; Orcaray Echeverría, Luis; Santesteban García, Gonzaga; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
The present systematic review aims to provide an overview of the impact of cover crops on vegetative growth and the productive parameters of vineyards. A systematic review was made on Scopus-index journals dating from 1999 to 2018. The selection was made at the same time by two different researchers, who selected a total of 272 published papers related to cover crops in vineyards. Each article was categorised according to its theme and a metadata database was created, considering all relevant information from an agronomic point of view for each article. It can be concluded from the review that the use of cover crops can reduce vine vegetative growth, which in turn can help keep the incidence of fungal diseases (like grey mould) at a low level. In general, this practice does not have a clear effect on vineyard yield or grape juice parameters, like total soluble solids (TSS) or titratable acidity (TA). Cover crops can decrease vineyard pests to a certain extent, especially Cicadellidae. Cover crops can sometimes sporadically cause water stress in the vineyard, but only during the summer months. This review allowed us to summarise available information on cover crops and their effects on vineyard agronomic performance in a systematic way. Such information can be used to help select the most suitable cover, based on specific vineyard objectives and growing conditions.
Open Access
Recovery of ancient grapevine plant material in peri‑urban areas. A case of success in Pamplona (Spain) leading to the recovery of cv. Berués
(Elsevier, 2022) Crespo Martínez, Sara; Mayor Azcona, Blanca; Oneka Mugica, Oihane; Loidi Erviti, Maite; Villa Llop, Ana; Marín Ederra, Diana; Miranda Jiménez, Carlos; Santesteban García, Gonzaga; Urrestarazu Vidart, Jorge; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB; Agronomía, Biotecnología y Alimentación; Gobierno de Navarra / Nafarroako Gobernua
Viticulture was relatively important in the peri‑urban area of Pamplona till the end of the 19th century, but suffered a continued regression that has led to a nearly complete disappearance of vineyards. In this context, this work aims to evaluate the feasibility of recovering old grapevine germplasm in the peri‑urban area of Pamplona. The lack of a conventional source for recovering plant material (i.e. absence of old vineyards in the area) implied the need of designing an alternative prospecting procedure. This method included the analysis of the available historical information as open-access resources (orthophotos, land use maps and GIS applications) aiming to identify the areas with the highest probability of finding vines surviving from the general abandonment and uprooting of vineyards that had occurred in the 20th century. Based on the oldest on scale orthophoto available for Navarra, a vineyard land map of the peri‑urban area of Pamplona in year 1956 was built, allowing prospecting efforts to be focused on specific areas of primarily interest. Following this strategy, a total of 120 plants were collected, which corresponded to 44 genotypes. The most prominent achievement of this prospecting mission was the recovery of 15 accessions of Berués, a very old variety with a remarkable importance in the region according to old historical records, and considered to be disappeared. The methodology proposed was effective in searching for the oldest standing-alone plants surviving in the peri‑urban area of Pamplona, and may be adapted to assist the recovery of old grapevine germplasm in other currently non wine-growing regions/areas where viticulture was relevant some decades ago. © 2021
Open Access
Oenological significance of vineyard management zones delineated using early grape sampling
(Springer, 2014) Urretavizcaya Sanz, Inés; Santesteban García, Gonzaga; Tisseyre, B.; Guillaume, S.; Miranda Jiménez, Carlos; Royo Díaz, José Bernardo; Producción Agraria; Nekazaritza Ekoizpena; Gobierno de Navarra / Nafarroako Gobernua, IIM11879.RI.1
Early definition of oenologically significant zones within a vineyard is one of the main goals of precision viticulture, as it would allow an increase in profitability through the adaptation of agronomic practices to the specific requirements of each zone, and/or segregation of the harvest into different batches to produce wines with different qualities. The aim of this work was to evaluate whether early grape sampling is a relevant tool for within-vineyard zone definition. The study was carried out in 2010 and 2011 in a 4.2 ha vineyard, where a grid of 60 sampling points was defined. 300-berry samples were picked from each sampling point after veraison and at harvest, post-veraison information being used to define zones within the vineyard after fuzzy k-means analysis and subsequent application of a zoning procedure that took into account membership degree and neighbourhood criteria. Two variations of the zoning procedure were used, standard (StdZ) and top (TopZ) zoning. Each was designed to meet different requirements of wineries; StdZ gave the same oenological relevance to all the zones, and TopZ differentiated the zones producing 'top class' grapes, minimizing the within-zone variability in the top-class zone. Grape composition obtained at harvest from the zones delineated post-veraison was compared. Zone delineation using post-veraison data was proved to be oenologically relevant, provided sampling is performed once veraison is completed. The two zoning algorithms designed were shown to be suitable for objective zone delineation according to the goals intended for each.
Open Access
Connection matters: exploring the implications of scion-rootstock alignment in grafted grapevines
(Australian Society of Viticulture and Oenology, 2022) Marín Ederra, Diana; Santesteban García, Gonzaga; Dayer, S.; Villa Llop, Ana; Abad Zamora, Francisco Javier; Gambetta, Gregory A.; Torres-Ruiz, J. M.; Torres Molina, Nazareth; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Gobierno de Navarra / Nafarroako Gobernua
Background and aims: grafting in viticulture has been essential since the advent of the phylloxera crisis at the end of the 19th century, but relatively little is known about the relevance of the quality of the connection at the grafting junction on the behaviour of grafted grapevines. Methods and results: an experimental procedure comparing omega grafted vines with complete alignment of the scion and the rootstock (CA) and vines with partial alignment (PA) was developed. Three complementary trials were carried out in the nursery, in the field and under controlled conditions. The CA vines increased the success rate in the nursery. Vine growth was significantly affected by the alignment between the rootstock and scion both in the nursery and in their first year of establishment in a commercial vineyard and in a potted trial, although these differences dissipated in years 2 and 3 under commercial vineyard conditions. The CA graft also maintained a higher level of leaf gas exchange, but such differences did not correspond to those in the hydraulic conductivity across the graft union itself. Conclusions: the degree of alignment of the grafted vine material affected vine development, but a better understanding of the role of vascular connections in different graft types and qualities is needed. Significance of the Study: to the best of our knowledge, this is the first scientific study that developed an experimental procedure for assessing the implication of the alignment at the grafting point on grapevine physiology and water use.
Open Access
Evaluation of the agronomic performance of 'Syrah' and 'Tempranillo' when grafted on 12 rootstocks
(Julius Kühn Institute (JKI), 2019) Marín Ederra, Diana; García, R.; Eraso Zabalegui, Javier; Urrestarazu Vidart, Jorge; Miranda Jiménez, Carlos; Royo Díaz, José Bernardo; Abad Zamora, Francisco Javier; Santesteban García, Gonzaga; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Beyond pest resistance, rootstocks significantly influence the performance of grapevine varieties. However, the effect of the rootstock is strongly affected by its interaction with the environment, and it is therefore necessary to evaluate their influence in a particular terroir. With the aim of evaluating the influence of 12 rootstocks on the agronomic performance of 'Syrah' and 'Tempranillo', a trial was established in 2011 and 2012 in Miranda de Arga (Navarra, Spain), under the typical environmental conditions of the Ebro Valley. Growth and yield, as well as industrial and phenolic maturity parameters were analysed during four consecutive seasons (2015-2018). Most rootstocks showed a similar performance with both varieties, not always following the trends reported in bibliography, which highlights the relevance of studying rootstocks in different conditions. 3309 C was the rootstock conferring the highest vigour, whereas the lowest were provided by 420 A MGt and 'Fercal'. The implications on grape composition were much more diverse, and were partially conditioned by yield. Results were obtained during the four first harvests of the vineyard, and could therefore change to some extent as the vineyard reaches stability.
Open Access
Hyperspectral imaging to assess the presence of powdery mildew (Erysiphe necator) in cv. Carignan Noir grapevine bunches
(MDPI, 2020) Pérez Roncal, Claudia; López Maestresalas, Ainara; López Molina, Carlos; Jarén Ceballos, Carmen; Urrestarazu Vidart, Jorge; Santesteban García, Gonzaga; Arazuri Garín, Silvia; Ingeniería; Estadística, Informática y Matemáticas; Agronomía, Biotecnología y Alimentación; Ingeniaritza; Estatistika, Informatika eta Matematika; Agronomia, Bioteknologia eta Elikadura; Gobierno de Navarra / Nafarroako Gobernua, Proyecto DECIVID (Res.104E/2017); Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, FPI-UPNA-2017 (Res.654/2017)
Powdery mildew is a worldwide major fungal disease for grapevine, which adversely affects both crop yield and produce quality. Disease identification is based on visible signs of a pathogen once the plant has already been infected; therefore, techniques that allow objective diagnosis of the disease are currently needed. In this study, the potential of hyperspectral imaging (HSI) technology to assess the presence of powdery mildew in grapevine bunches was evaluated. Thirty Carignan Noir grape bunches, 15 healthy and 15 infected, were analyzed using a lab-scale HSI system (900–1700 nm spectral range). Image processing was performed to extract spectral and spatial image features and then, classification models by means of Partial Least Squares Discriminant Analysis (PLS-DA) were carried out for healthy and infected pixels distinction within grape bunches. The best discrimination was achieved for the PLS-DA model with smoothing (SM), Standard Normal Variate (SNV) and mean centering (MC) pre-processing combination, reaching an accuracy of 85.33% in the cross-validation model and a satisfactory classification and spatial location of either healthy or infected pixels in the external validation. The obtained results suggested that HSI technology combined with chemometrics could be used for the detection of powdery mildew in black grapevine bunches.