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.
Embargo
Upgrading and validating a soil water balance model to predict stem water potential in vineyards
(Elsevier, 2024-12-15) Mirás-Ávalos, José M.; Escalona, José M.; Pérez-Álvarez, Eva Pilar; Romero Azorín, Pascual; Botia, Pablo; Navarro, Josefa; Torres Molina, Nazareth; Santesteban García, Gonzaga; Uriarte, David; Intrigliolo, Diego S.; Buesa, Ignacio; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB
Efficient water management is pivotal for viticulture sustainability. Decision support tools can advise on how to optimize irrigation or on the feasibility of growing grapes in rainfed conditions, but reliable algorithms for assessing vine water status are required. In this context, the aim of the current study was to upgrade a soil water balance model specific for vineyards by incorporating meteorological, soil and vine vigor in equations that transform the fraction of transpirable soil water into midday stem water potential (Ψstem). The model's sensitivity to variations in the magnitude of input parameters was analyzed. Furthermore, the model was tested in a broad scope of Spanish vineyards with different grapevine cultivars (both red and white), rootstocks, plant age, soil and climatic conditions, and water regimes, totaling 129 scenarios. The model was only slightly sensitive to variations in the magnitude of most inputs, except for the fraction of transpirable water at which leaf stomatal conductance begin to decline. Moreover, the model satisfactorily reproduced the evolution of Ψstem over the growing season, although it slightly overestimated the measured ¿stem values, as the slopes of the fitted regression lines were lesser than 1 on most occasions, 76 out of 129. Nonetheless, the coefficients of determination for these relationships were greater than 0.9, except for 21 datasets. Mean errors averaged 0.024 ± 0.015 MPa, while root mean square errors averaged 0.27 ± 0.01 MPa. The index of agreement was greater than 0.75 in 51 datasets, with only three datasets showing an index of agreement lower than 0.5. Nevertheless, the deviations between observed and simulated Ψstem values did not alter the classification of the water stress undergone by grapevines. This upgraded model could constitute the core of a decision support system for water management in vineyards, applicable to both rainfed and irrigated conditions.
Open Access
Conventional and newly bred rootstock effects on the ecophysiological response of Vitis vinifera L. cv. Tempranillo
(Elsevier, 2023) Buesa, Ignacio; Torres Molina, Nazareth; Tortosa, Ignacio; Marín Ederra, Diana; Villa Llop, Ana; Douthe, Cyril; Santesteban García, Gonzaga; Medrano, H.; Escalona, José M.; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB
Achieving more environmentally sustainable vineyards, particularly regarding efficient water use, is paramount in semi-arid grape-growing regions. Rootstocks may be a possible strategy to address these challenges, but require a comprehensive evaluation of their effect on the scion, including ecophysiological traits. The objectives of this study were 1) to characterize the physiological response of Tempranillo cultivar grafted onto five commercial (1103 P, 110 R, 140Ru, 420 A, and SO4), and seven recently bred (RG2, RG3, RG4, RG6, RG7, RG8 and RG9) rootstocks and 2) to elucidate the relationships between agronomic and physiological traits conferred by grapevine rootstocks. This was carried out over three seasons (2018–2020) in a typical Mediterranean vineyard by determining water relations, leaf gas exchange, carbon isotope ratios and vegetative development and yield components. The results highlighted the different behaviour of ‘Tempranillo’ vines due to the rootstock effects on vine water status, photosynthetic performance, hydraulic conductance, vegetative growth and yield parameters. Overall, rootstocks inducing vigour and yield in the scion, such as 140Ru and RG8, showed higher leaf gas exchange rates and hydraulic conductance at the whole-plant level due to less negative water potentials, suggesting a higher water uptake and transport capacity than RG2, RG7 and RG9. The RG rootstocks showed a very wide range of ecophysiological responses, but only RG8 outperformed compared to the most widely used commercial rootstocks. Moreover, this response was modulated by the season and the block soil type, suggesting the importance of rootstock selection according to the edaphoclimatic conditions. Therefore, this study highlights the high potential of rootstocks to adapt to water scarcity by improving crop water productivity in vineyards and provides physiological insights for future studies and breeding programmes.
Open Access
Guía de buenas prácticas para la elección del material de plantación de un viñedo
(2023) García García, Rafael; Eraso Zabalegui, Javier; Villa Llop, Ana; Santesteban García, Gonzaga; Crespo Martínez, Sara; Gambra, Alberto; Palacios Muruzábal, Julián; Sebastián Caumel, Bárbara; Urrestarazu Vidart, Jorge; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB; Agronomía, Biotecnología y Alimentación
Esta es una guía gráfica sobre la elección del material vegetal para la plantación de un viñedo. Mediante vídeos sencillos se explican factores agronómicos claves a tener en cuenta antes de realizar una plantación, además de nociones básicas que se deben conocer para la elección del material vegetal. Hemos estructurado esta Guía en tres bloques, partiendo del objetivo principal que es la obtención de un viñedo equi- librado, siguiendo con la explicación de las distintas calida- des genéticas que se pueden elegir a la hora de comprar el material vegetal; y concluyendo con vídeos sobre la calidad fisiológica de la planta y cómo comprobarla. Con los últimos vídeos, más científicos, queremos explicar qué sucede a nivel celular en la zona del punto de injerto para que las conexiones vasculares se puedan generar. Los aspectos clave a destacar a la hora de la elección del material vegetal serían: • Saber medir/cuantificar las cualidades y limitaciones de la parcela. • Conocer el abanico de posibilidades en cuanto al material genético disponible. • Saber comprobar la calidad fisiológica del material vegetal. Y fundamental para realizar una plantación con éxito, es tener la máxima información posible como mínimo un año antes de realizar la plantación del viñedo.
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
IV Jornadas del Grupo de Viticultura: comunicaciones técnicas Sociedad Española de Ciencias Hortícolas
(Sociedad Española de Ciencias Hortícolas, 2022) Santesteban García, Gonzaga; Torres Molina, Nazareth; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
La Sociedad Española de Ciencias Hortícolas y la Universidad Pública de Navarra organizaron las IV Jornadas del grupo de Viticultura de la SECH, celebradas en Pamplona/Iruña entre los días 26 y 28 de octubre de 2022. Las Jornadas, promovidas por el Grupo de Trabajo de Viticultura de la SECH, tuvieron como objetivo principal poner en común los trabajos realizados en los últimos años en el ámbito de la viticultura y de la investigación vitícola. Los últimos años, marcados por la crisis provocada por la pandemia del COVID-19, impidieron la realización de las Jornadas del grupo con anterioridad. Estas IV Jornadas se dedicaron a reflexionar sobre la investigación en el sector en los últimos años, su transferencia y su impacto en la sociedad. En este contexto, las Jornadas pretenden ser un encuentro abierto en el que los investigadores, docentes, técnicos, centros de investigación, sectores económicos y productivos expongan sus trabajos de investigación, de desarrollo y de aplicación tecnológica.
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
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
Cubierta vegetal bajo las cepas: una alternativa al control de las malas hierbas en los viñedos
(INTIA (Tecnologías e Infraestructuras Agroalimentarias), 2023) Abad Zamora, Francisco Javier; Cibriain Sabalza, Félix; Sagüés Sarasa, Ana; Santesteban García, Gonzaga; Lezáun San Martín, Juan Antonio; Fabo Boneta, Jesús María; Virto Quecedo, Íñigo; Imbert Rodríguez, Bosco; Marín Arroyo, Remedios; Garbisu Crespo, Carlos; Ciencias; Zientziak; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD
En este artículo se presentan los resultados obtenidos con una cubierta vegetal de trébol sembrada bajo las cepas para competir con las malas hierbas, de manera que no sea necesario recurrir al empleo de herbicidas o laboreos intercepas.
Open Access
Exploring the potential of hyperspectral imaging to detect Esca disease complex in asymptomatic grapevine leaves
(Elsevier, 2022) Pérez Roncal, Claudia; Arazuri Garín, Silvia; López Molina, Carlos; Jarén Ceballos, Carmen; Santesteban García, Gonzaga; López Maestresalas, Ainara; Ingeniaritza; Estatistika, Informatika eta Matematika; Agronomia, Bioteknologia eta Elikadura; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Ingeniería; Estadística, Informática y Matemáticas; Agronomía, Biotecnología y Alimentación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Precise and reliable identification of specific plant diseases is a challenge within precision agriculture nowadays. This is the case of esca, a complex grapevine trunk disease, that represents a major threat to modern viticulture as it is responsible for large economic losses annually. The lack of effective control strategies and the complexity of esca disease expression make essential the identification of affected plants, before symptoms become evident, for a better management of the vineyard. This study evaluated the suitability of a near-infrared hyperspectral imaging (HSI) system to detect esca disease in asymptomatic grapevine leaves of Tempranillo red-berried cultivar. For this, 72 leaves from an experimental vineyard, naturally infected with esca, were collected and scanned with a lab-scale HSI system in the 900-1700 nm spectral range. Then, effective image processing and multivariate analysis techniques were merged to develop pixel-based classification models for the distinction of healthy, asymptomatic and symptomatic leaves. Automatic and interval partial least squares variable selection methods were tested to identify the most relevant wavelengths for the detection of esca-affected vines using partial least squares discriminant analysis and different pre-processing techniques. Three-class and two-class classifiers were carried out to differentiate healthy, asymptomatic and symptomatic leaf pixels, and healthy from asymptomatic pixels, respectively. Both variable selection methods performed similarly, achieving good classification rates in the range of 82.77-97.17% in validation datasets for either three-class or two-class classifiers. The latter results demonstrated the capability of hyperspectral imaging to distinguish two groups of seemingly identical leaves (healthy and asymptomatic). These findings would ease the annual monitoring of disease incidence in the vineyard and, therefore, better crop management and decision making.