Open Access
A water content continuous monitoring of grapevine xylem tissue using a portable low-power cost-effective FMCW radar
(IEEE, 2019) Quemada Mayoral, Carlos; García González, Cebrián; Iriarte Galarregui, Juan Carlos; Marín Ederra, Diana; Gastón Beraza, Diego; Miranda Jiménez, Carlos; Gonzalo García, Ramón; Maestrojuán Biurrun, Itziar; Santesteban García, Gonzaga; Ederra Urzainqui, Íñigo; Agronomia, Bioteknologia eta Elikadura; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Agronomía, Biotecnología y Alimentación; Ingeniería Eléctrica, Electrónica y de Comunicación; Gobierno de Navarra / Nafarroako Gobernua, PI025 VITHZ; Gobierno de Navarra / Nafarroako Gobernua, 0011-1365-2016-000084 RAFF
This paper presents the real-time monitoring of a grapevine’s water content that flows up through the xylem tissue by means of a frequency-modulated continuous-wave (FMCW) radar. The application of an optimization process, based on the super-resolution multiple signal classification (MUSIC) algorithm, has enabled the reduction of the bandwidth required to discern the xylem water content, and thus the operating frequency, achieving a depth resolution of at least 3 mm. This design advantage has resulted in a significant step forward towards a real life application, allowing the use of fully-integrated off-the-shelf components in order to implement a completely portable low-power cost-effective radar at 23.1 GHz with a 3.4 GHz bandwidth. The sensor performance has been evaluated by means of three different experiments: irrigation cycles, day/night cycles and comparison between irrigation cycles at different temperatures. From the experimental results, it is possible to assert that the contactless sensor presented in this work is very sensitive to changes in the plant’s water content, differentiating between daytime and nighttime. In addition, it has been proved that temperature has a noticeable influence over the evapotranspiration, observing negative drying slopes of 5.62 mV/cycle and 6.28 mV/cycle at 23ºC and 26ºC respectively.
Open Access
Sampling stratification using aerial imagery to estimate fruit load in peach tree orchards
(MDPI, 2018) Miranda Jiménez, Carlos; Santesteban García, Gonzaga; Urrestarazu Vidart, Jorge; Loidi Erviti, Maite; Royo Díaz, José Bernardo; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
A quick and accurate sampling method for determining yield in peach orchards could lead to better crop management decisions, more accurate insurance claim adjustment, and reduced expenses for the insurance industry. Given that sample size depends exclusively on the variability of the trees on the orchard, it is necessary to have a quick and objective way of assessing this variability. The aim of this study was to use remote sensing to detect the spatial variability within peach orchards and classify trees into homogeneous zones that constitute sampling strata to decrease sample size. Five mature peach orchards with different degrees of spatial variability were used. A regular grid of trees was established on each orchard, their trunk cross-sectional area (TCSA) was measured, and yield was measured as number of fruits/tree on the central tree of each one of them. Red Vegetation Index (RVI) was calculated from aerial images with 0.25 m pixel -1 resolution, and used, either alone or in combination with TCSA, to delineate sampling strata using cluster fuzzy k-means. Completely randomized (CRS) and stratified samplings were compared through 10,000 iterations, and the Minimum Sample Size required to obtain estimates of actual production for three quality levels of sampling was calculated in each case. The images allowed accurate determination of the number of trees, allowing a proper application of completely randomized sampling designs. Tree size and the canopy density estimated by means of multispectral indices are complementary parameters suitable for orchard stratification, decreasing the sample size required to determine fruit count up to 20–35% compared to completely randomized samples.
Open Access
Quantifying the effects of water status on grapevine vegetative growth, yield, and grape composition through a collaborative analysis
(Wiley, 2025-05-14) Contreras Uriarte, David; Santesteban García, Gonzaga; Mirás-Ávalos, José M.; Buesa, Ignacio; Cancela, Javier José; Chacón, Juan Luis; Escalona, José M.; Intrigliolo, Diego S.; Lampreave, Miriam; Montoro, Amelia; Rivacoba Gómez, Luis; Visconti, Fernando; Yuste, Jesús; Miranda Jiménez, Carlos; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
The consolidation of scientific knowledge is based on the accumulation and understanding of previous findings. Nowadays, reviews of the scientific literature have become more effective through the use of meta-analyses, which are systematic evaluations of the results from multiple studies. Similarly, mega-analyses, which combine raw data from many studies into a single sample for processing and statistical analysis, are a very powerful tool for analyzing results of heterogeneous origin but require a high level of collaboration between the researchers contributing data. In the framework of a collaborative methodology between different Spanish viticultural research groups, this work uses a mega-analytical approach to quantify the effects of changes in vine water status on vine vegetative growth, yield, and grape composition, integrating a wide range of growing conditions to obtain robust general trends of vine performance under water deficit. The mean seasonal stem water potential data from the different studies allowed a classification into five levels of water status (no deficit ⟶ mild ⟶ moderate ⟶ high ⟶ severe). A progressive decrease in vegetative growth with increasing deficit was observed, while yield decreased more markedly as water deficit progressed from moderate to high. On the other hand, titratable acidity was more sensitive to variation in water status than sugar concentration, with a greater decrease in titratable acidity when changing from no to moderate deficit. Conversely, increasing water deficit from moderate to high resulted in the greatest increases in grape anthocyanin in the red varieties explored. The results obtained in this work provide solid information on general trends in grapevine response to water deficit that can be used in simulation models or incorporated by grape growers in their decision-making processes in relation not only to irrigation management but also on other agronomic tools to impact grapevine water status.
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
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
Agronomic evaluation of eight 41 B × 110 richter grapevine genotypes as rootstock candidates for mediterranean viticulture
(KeAi Communications, 2023) Marín Ederra, Diana; Miranda Jiménez, Carlos; Abad Zamora, Francisco Javier; Urrestarazu Vidart, Jorge; Mayor Azcona, Blanca; Villa Llop, Ana; Santesteban García, Gonzaga; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Choosing the most appropriate rootstock(s) is a key decision for the profitability of vineyards; therefore, there must be a sufficient range of rootstocks in the market adapted to different environmental conditions and production objectives. However, rootstock-breeding programs have been scarce in recent decades, and most of the rootstocks used today were bred a century ago, when the needs of the sector were very different from today. In this work, we aimed to evaluate new rootstock candidates before their introduction in the market. An agronomic evaluation was conducted on eight novel rootstock genotypes obtained from the first generation of the cross-pollination of 41 B Millardet et de Grasset (41 B) and 110 Richter (110 R) grafted with ‘Syrah’ and ‘Tempranillo’ and planted in a typical vineyard of the Ebro Valley in Spain. During the four consecutive growing seasons (2016e2019), growth, yield and berry composition parameters at harvest were collected. A linear mixedeffects model was constructed, considering year and block as random effects. Multiple factor analysis and hierarchical clustering on principal components were performed to establish clusters of genotypes with similar behaviour. The rootstock candidates showed a very wide performance range compared to their parents. The trial allowed us to identify two very promising candidates (RG8 and RG10), whose registration as commercial rootstocks is already in progress.
Open Access
Relevance of sink-size estimation for within-field zone delineation in vineyards
(Springer, 2017) Urretavizcaya Sanz, Inés; Royo Díaz, José Bernardo; Miranda Jiménez, Carlos; Tisseyre, B.; Santesteban García, Gonzaga; Producción Agraria; Nekazaritza Ekoizpena; Gobierno de Navarra / Nafarroako Gobernua, IIM11879.RI.1
Source to sink size ratio, i.e.: the relative abundance of photosynthetically active organs (leaves) with regards to photosynthate demanding organs (mainly bunches), is widely known to be one of the main drivers of grape oenological quality. However, due to the difficulty of remote sink size estimation, Precision Viticulture (PV) has been mainly based on within-field zone delineation using vegetation indices. This approach has given only moderately satisfactory results for discriminating zones with differential quality. The aim of this work was to investigate an approach to delineate within-vineyard quality zones that includes an estimator of sink size in the data-set. The study was carried out during two consecutive seasons on a 4.2 ha gobelet-trained cv. 'Tempranillo' vineyard. Zone delineation was performed using Normalized Difference Vegetation Index (NDVI), soil apparent electrical conductivity (ECa) and bunch number (BN) data. These variables were considered separately, in pairs, or the three altogether, using fuzzy k-means cluster analysis for combinations. The zones delineated based on single variables did not allow a sufficient discrimination for grape composition at harvest, NDVI being the only variable that by itself resulted in zones that to some extent differed in grape composition. On the contrary, when two variables were combined, discrimination in terms of grape composition improved remarkably, provided the sink size estimation variable (BN) was included in the combination. Lastly, the combination of the three variables yielded the best discriminating zoning, improving slightly on those provided by NDVI + BN and ECa + BN combinations. Thus, the relevance of including a variable related to sink size (in this case the number of bunches per plant) has been confirmed, which makes its consideration highly advisable for any PV work aiming at zone delineation for grape quality purposes.
Open Access
The role of rootstocks for grape growing adaptation to climate change: meta-analysis of the research conducted in Spanish viticulture
(International Viticulture and Enology Society, 2023) Santesteban García, Gonzaga; Rekarte, Isabel; Torres Molina, Nazareth; Galar Martínez, Mónica; Villa Llop, Ana; Visconti, Fernando; Intrigliolo, Diego S.; Escalona, José M.; Herralde, Felicidad de; Miranda Jiménez, Carlos; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB
Rootstock election is one of the key decisions when designing a vineyard. Although the research performed to determine the effect they induce in the behaviour of scion varieties is not scarce, it is not easy to have a global idea, as results are usually published scattered. In this work, we re-examine previous research conducted in Spain on rootstock implications on vine agronomic performance through the performance of a meta-analysis (MA). As a result, we were able to integrate the information reported in 20 articles that included rootstock experimentation conducted with 36 different varieties and 47 different rootstocks, totalling 764 individual records. However, when the information was filtered before the meta-analysis, this number decreased to 312 records, for which rootstock Response Ratios (RR) were calculated. The characteristics conferred by the rootstock were more closely related to the rootstock itself, rather than to the characteristics of the Vitis sp. crossing used to create the rootstock. Several rootstocks were identified as more suitable for adapting to future climate change conditions, as far as they were able to moderate sugar accumulation and pH (161-49 C, 41-B MGt and 420A MGt). Meanwhile, 140 Ru and 5-BB were observed to provide high pH and sugar contents despite their high yield. In conclusion, despite being based on data from a single country, the meta-analysis was shown to be a useful tool for enhancing the value of previous research on rootstocks. Combining articles from both peer-reviewed and technical journals helped in the assessment of the implications of different rootstocks, although further steps should be taken to facilitate data integration (harmonisation of measurement and reporting procedures, open data repositories, etc).
Open Access
Genetic diversity of Spanish Prunus domestica L. germplasm reveals a complex genetic structure underlying
(Public Library of Science, 2018) Urrestarazu Vidart, Jorge; Errea, Pilar; Miranda Jiménez, Carlos; Santesteban García, Gonzaga; Pina, Ana; Producción Agraria; Nekazaritza Ekoizpena
European plum (Prunus domestica L.) is an ancient domesticated species cultivated in temperate areas worldwide whose genetic structure has been scarcely analyzed to date. In this study, a broad representation of Spanish European plum germplasm collected in Northeastern Spain and a representative set of reference cultivars were compared using nuclear and chloroplast markers. The number of alleles per locus detected with the SSR markers ranged from 8 to 39, with an average of 23.4 alleles, and 8 haplotypes were identified. Bayesian model-based clustering, minimum spanning networks, and the analysis of molecular variance showed the existence of a hierarchical structure. At the first level, two genetic groups were found, one containing 'Reine Claude' type reference cultivars altogether with ca. 25% of local genotypes, and a second one much more diverse. This latter group split in two groups, one containing most (ca. 70%) local genotypes and some old Spanish and French reference cultivars, whereas the other included 24 reference cultivars and only six local genotypes. A third partition level allowed a significant finer delineation into five groups. As a whole, the genetic structure of European plum from Northeastern Spain was shown to be complex and conditioned by a geographical proximity factor. This study not only contributes to genetic conservation and breeding for this species at the national level, but also supports the relevance of undertaking similar tasks of collection and characterization in other unexplored areas. Moreover, this kind of research could lead to future coordinated actions for the examination of the whole European plum diversity, to define conservation strategies, and could be used to better understand the genetic control of traits of horticultural interest through association mapping.
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.