Agronomy

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17 pages, 1297 KiB

Open AccessArticle

Determining Irrigation Requirements of Extensive Crops Using the Typical Meteorological Year Adjusted to the Growing Cycle Period

by Antonio Cano, José Jesús Pardo, Jesús Montero and Alfonso Domínguez

Agronomy 2022, 12(9), 2208; https://doi.org/10.3390/agronomy12092208 - 16 Sep 2022

Cited by 1 | Viewed by 1941

Abstract

In the Castilla-La Mancha (CLM, Spain) region, most of the irrigated area is managed by two different strategies in which the previously defined irrigation requirements of crops affect both the distribution of crops and the sustainable management of groundwater resources. Thus, in the [...] Read more.

In the Castilla-La Mancha (CLM, Spain) region, most of the irrigated area is managed by two different strategies in which the previously defined irrigation requirements of crops affect both the distribution of crops and the sustainable management of groundwater resources. Thus, in the western Mancha system, the amount of irrigation water per farm is limited, while in the eastern Mancha system the irrigable area per farm is limited. Therefore, the use of average irrigation requirements in these areas may cause yield drops in dry years and the overuse of groundwater. Consequently, the main aim was to achieve a better approach to the irrigation requirements of the main extensive crops in CLM (maize (Zea mays L.), onion (Allium cepa L.), garlic (Allium sativum L.), and barley (Hordeum vulgare L.)) to help farmers and water authorities achieve higher yields and a more sustainable use of water resources. The typical meteorological year (TMY) methodology combined with the MOPECO model were used to: (1) determine the distribution of wet, intermediate, and dry years during the growing cycle of the four selected crops; (2) determine the average (AVE) and typical irrigation requirements of these crops for the complete 70 years series (TMY_G) or the duration of the crop cycle (TMY_C), and under wet (TMY_W), intermediate (TMY_I), and dry (TMY_D) year conditions; and (3) recommend the irrigation depths to be used for the management of farms and water bodies. The results show that the number of wet, intermediate, and dry years depends on the growing cycle of the crop considered, with wet years being unusual, although they notably increase the average rainfall in the area. The irrigation requirements for the average year were between 20.4 and 9.0% lower than the average irrigation requirements calculated for the four studied crops during the 70 years of the series. For western Mancha farmers the recommended irrigation depth for dry years and most profitable crops (garlic and onion) is the one calculated for the driest year of the series, while for the rest of the years and crops is that estimated by the global dry TMY (TMY_GD). For eastern Mancha farmers the recommended irrigation depths are also those estimated by the TMY_GD. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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17 pages, 2375 KiB

Open AccessEditor’s ChoiceArticle

Analysis of Biophysical Variables in an Onion Crop (Allium cepa L.) with Nitrogen Fertilization by Sentinel-2 Observations

by Alejandra Casella, Luciano Orden, Néstor A. Pezzola, Carolina Bellaccomo, Cristina I. Winschel, Gabriel R. Caballero, Jesús Delegido, Luis Manuel Navas Gracia and Jochem Verrelst

Agronomy 2022, 12(8), 1884; https://doi.org/10.3390/agronomy12081884 - 11 Aug 2022

Cited by 8 | Viewed by 3374

Abstract

The production of onions bulbs (Allium cepa L.) requires a high amount of nitrogen. According to the demand of sustainable agriculture, the information-development and communication technologies allow for improving the efficiency of nitrogen fertilization. In the south of the province of Buenos [...] Read more.

The production of onions bulbs (Allium cepa L.) requires a high amount of nitrogen. According to the demand of sustainable agriculture, the information-development and communication technologies allow for improving the efficiency of nitrogen fertilization. In the south of the province of Buenos Aires, Argentina, between 8000 and 10,000 hectares per year⁻¹ are cultivated in the districts of Villarino and Patagones. This work aimed to analyze the relationship of biophysical variables: leaf area index (LAI), canopy chlorophyll content (CCC), and canopy cover factor (fCOVER), with the nitrogen fertilization of an intermediate cycle onion crop and its effects on yield. A field trial study with different doses of granulated urea and granulated urea was carried out, where biophysical characteristics were evaluated in the field and in Sentinel-2 satellite observations. Field data correlated well with satellite data, with an R² of 0.91, 0.96, and 0.85 for LAI, fCOVER, and CCC, respectively. The application of nitrogen in all its doses produced significantly higher yields than the control. The LAI and CCC variables had a positive correlation with yield in the months of November and December. A significant difference was observed between U250 (62 Mg ha⁻¹) and the other treatments. The U500 dose led to a yield increase of 27% compared to U250, while the difference between U750 and U500 was 6%. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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8 pages, 769 KiB

Open AccessArticle

Acoustic and Thermal Properties of Particleboards Made from Mulberry Wood (Morus alba L.) Pruning Residues

by Manuel Ferrandez-Villena, Antonio Ferrandez-Garcia, Teresa Garcia-Ortuño and Maria Teresa Ferrandez-Garcia

Agronomy 2022, 12(8), 1803; https://doi.org/10.3390/agronomy12081803 - 29 Jul 2022

Cited by 7 | Viewed by 2799

Abstract

The aim of this study was to determine the acoustic and thermal properties of particleboards made from mulberry wood pruning waste using urea formaldehyde resin (UF) as a binder. The investigation focused on the evaluation of the thermal conductivity and the acoustic absorption [...] Read more.

The aim of this study was to determine the acoustic and thermal properties of particleboards made from mulberry wood pruning waste using urea formaldehyde resin (UF) as a binder. The investigation focused on the evaluation of the thermal conductivity and the acoustic absorption of the boards and the assessment of their feasibility for use in the construction sector. The mean thermal conductivity values of the particleboards (0.065–0.068 W/mK) were lower than those obtained in wood and similar to those in cork panels. The samples were tested with frequencies from 50 to 6300 Hz. In all cases, the results allowed us to conclude that they were better sound absorbers than commercial wood and plywood panels of the same average density for low frequencies, and with similar values for medium and high frequencies. The mechanical results reached the minimum requirement to be considered as boards for general use and, specifically with particles from 0.25 to 1.00 mm, for furniture according to European standards. The particle size of the particleboards was the variable that influenced all the acoustic properties, but did not affect the thermal conductivity. The experimental results indicated that the thermal and acoustic properties of these particleboards were promising for their application in commercial uses. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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13 pages, 3369 KiB

Open AccessArticle

Textile Physical Barriers against the Chestnut Gall Wasp Dryocosmus kuriphilus

by Antonio J. Álvarez and Rocío M. Oliva

Agronomy 2022, 12(7), 1728; https://doi.org/10.3390/agronomy12071728 - 21 Jul 2022

Cited by 2 | Viewed by 1915

Abstract

Dryocosmus kuriphilus Yasumatsu is a species originating from China that, during the 20th century, has spread rapidly throughout many countries, affecting mainly different species of the genus Castanea spp. In fact, it is considered to be the most important pest of chestnut trees [...] Read more.

Dryocosmus kuriphilus Yasumatsu is a species originating from China that, during the 20th century, has spread rapidly throughout many countries, affecting mainly different species of the genus Castanea spp. In fact, it is considered to be the most important pest of chestnut trees (Castanea sativa Miller), causing significant production losses. The adoption of complementary measures to chemical and biological controls would contribute to the control of the pest. In this sense, the use of textile physical barriers could prevent the rapid spread of this species among the production centers. Therefore, the objective of this study is to define the characteristics of a textile that protects young plants that have been produced in nurseries. For this purpose, some commercial textiles have been selected based on the morphometric characterization of the species and these textiles have been accurately measured in order to compare their dimensions with those of the insects. Finally, tests have been carried out in order to measure the efficacy of the textiles under laboratory conditions, controlling the air velocity and the temperature. The results reveal that, in general, theoretical efficacy may not be a good predictor of practical results. A fully effective screen has been found against this species and its design characteristics can be used as a starting point for new, more optimized designs. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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13 pages, 3861 KiB

Open AccessArticle

Fatal Tractor Accidents in the Agricultural Sector in Spain during the Past Decade

by Carmen Jarén, Alicia Ibarrola, Txuma Mangado, Aritz Adin, Pedro Arnal, Ainara López-Maestresalas, Alonso Ríos and Silvia Arazuri

Agronomy 2022, 12(7), 1694; https://doi.org/10.3390/agronomy12071694 - 17 Jul 2022

Cited by 13 | Viewed by 3255

Abstract

Currently, there is a discrepancy between the number of occupational accidents in the agricultural sector reported by Spanish governmental sources and those actually occurring in general. This is mainly due to the official definition of ‘occupational accident’ in the current regulations. In order [...] Read more.

Currently, there is a discrepancy between the number of occupational accidents in the agricultural sector reported by Spanish governmental sources and those actually occurring in general. This is mainly due to the official definition of ‘occupational accident’ in the current regulations. In order to be able to analyse all fatal accidents involving tractors, other sources of information must therefore be used. In this study, we have collected the news published in different media during the period 2010–2019. Statistical models that take into account the spatial and temporal dependence of the data were used to estimate the rates of fatal accidents in the provinces of Spain using the Bayesian inference technique INLA (Integrated Nested Laplace Approximation). The results obtained showed that the total number of fatal accidents in that period was 644. The crude rates of fatal accidents per province ranged from 0 to 223.5 fatal accidents per 100,000 registered tractors. In addition, the overall rate for Spain as a whole was 6.87 fatal accidents per 100,000 tractors. As in other EU countries, it was found that the regions with the highest number of accidents were also related to steep terrain, to an older tractor fleet and to horticultural crops and vineyards. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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18 pages, 8074 KiB

Open AccessArticle

Actions for Monitoring the Gonipterus Pest in Eucalyptus on the Cantabrian Coast

by Esperanza Ayuga-Téllez, Alberto García-Iruela, José Causí Rielo and Concepción González-García

Agronomy 2022, 12(7), 1692; https://doi.org/10.3390/agronomy12071692 - 16 Jul 2022

Cited by 4 | Viewed by 2014

Abstract

Forests are a natural resource of great importance for sustainable development. They represent the primary use of Spanish territory and cover 36% of its area. Eucalyptus shrublands are the most productive, particularly on the Cantabrian coast, occupying a total area of 406,566 ha. [...] Read more.

Forests are a natural resource of great importance for sustainable development. They represent the primary use of Spanish territory and cover 36% of its area. Eucalyptus shrublands are the most productive, particularly on the Cantabrian coast, occupying a total area of 406,566 ha. Since 1991, some of these shrublands have been affected by the eucalyptus snout beetle (Gonipterus platensis), a coleoptera (weevil) from the Curculionidae family that feeds on eucalyptus leaves and produces significant damage. The innovation project of the Supra-regional Operational Health Group on Gonipterus in Eucalyptus was developed (2019–2020) to establish a global approach to the serious problem it causes in Asturias and Galician Eucalyptus stands. A group of experts devised two action protocols to unify the methods and variables measured in the field: a protocol for measuring and estimating damage (degree of defoliation) and a parasitism protocol to establish actions to monitor the degree of parasitism (collection of oothecae, management of the sample, laboratory procedure). In the results, in addition to establishing the sampling protocol, an analysis of the data (from 2017 to spring 2020) provided by the different administrations of the Autonomous Communities studied has been carried out. The data analysis reveals an improvement in the impact of the damage on the Cantabrian coast (29.8% reduction in damage in Galicia and 14.7% in Asturias). In Galicia, the number of adult insects decreased from 2017 to 2019, increasing in the spring (from April to June) of 2020 above the mean values of previous years in that period. The number of larvae in the different larval stages showed similar development in all cases. The mean larvae (in their different stages) and mean oothecae showed a significant decline in the year 2018 compared to the spring of 2017, with an upturn in 2019 and again similar values to 2018 in the spring of 2020. In Asturias, similar mean values of the order of 0.5 insects per plot on dates (May–June) in spring were observed in 2019. While in 2020, a progressive increase could be seen in the mean number of insects throughout March, up to 1.9 insects per plot. Results of research on the biological treatment of parasitisation of oothecae with A.nitens were also collected to adjust the number of oothecae per bag deposited in the field and the number of Anaphes released per ha. Based on the field observations, the appropriate release time was determined to succeed in controlling the Gonipterus population. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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13 pages, 1035 KiB

Open AccessArticle

Environmental LCA of Precision Agriculture for Stone Fruit Production

by Pablo Núñez-Cárdenas, Belén Diezma, Guillermo San Miguel, Constantino Valero and Eva C. Correa

Agronomy 2022, 12(7), 1545; https://doi.org/10.3390/agronomy12071545 - 28 Jun 2022

Cited by 11 | Viewed by 2842

Abstract

Precision agriculture is a concept that encompasses various technologies aimed at optimizing the management of agricultural activities. The main aim of this investigation is to evaluate the environmental and economic performance of precision agriculture practices on the production of a stone fruit crop [...] Read more.

Precision agriculture is a concept that encompasses various technologies aimed at optimizing the management of agricultural activities. The main aim of this investigation is to evaluate the environmental and economic performance of precision agriculture practices on the production of a stone fruit crop (nectarine) using a life cycle approach and to consider a cradle-to-farm gate scope. The results have been compared against the traditional uniform application (UA). The analysis considers five impact categories, including climate change, photochemical ozone formation, acidification, eutrophication, and water use. The foreground inventory data was provided by a local producer in Southern Spain, and the background information was sourced from commercial Life Cycle Inventory (LCI) databases. The results show that the manufacturing of crop inputs (mainly fertilizers, but also crop management inputs) is responsible for most of the damage generated in all the impact categories, except for water use. The reduced input requirements associated with the application of VA techniques resulted in significantly lower economic costs and environmental savings throughout the life cycle of the production system, which ranged on average between 12–26%. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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46 pages, 12244 KiB

Open AccessArticle

Effect of the Airblast Settings on the Vertical Spray Profile: Implementation on an On-Line Decision Aid for Citrus Treatments

by Cruz Garcera, Enrique Moltó, Héctor Izquierdo, Paolo Balsari, Paolo Marucco, Marco Grella, Fabrizio Gioelli and Patricia Chueca

Agronomy 2022, 12(6), 1462; https://doi.org/10.3390/agronomy12061462 - 17 Jun 2022

Cited by 5 | Viewed by 2609

Abstract

Airblast sprayers are widely used for the application of plant protection products (PPP) in citrus. Adaptation of the vertical distribution of the spray cloud to the canopy (density, shape and size), is essential to deposit an adequate amount of PPP on the target [...] Read more.

Airblast sprayers are widely used for the application of plant protection products (PPP) in citrus. Adaptation of the vertical distribution of the spray cloud to the canopy (density, shape and size), is essential to deposit an adequate amount of PPP on the target and to reduce losses (drift, runoff). Vertical spray profiles of three air-assisted axial fan hydraulic sprayers with different configurations and settings were obtained to evaluate the effect of these settings on the vertical spray profile. From the analysis of the empirical results, the impact of operational settings (nozzle, air volume and flow rate) on treatment efficiency is assessed. The empirical database generated in this work has been employed to feed the Citrus VESPA model, a highly intuitive, web-based decision aid tool that helps farmers to easily estimate the vertical spray profiles generated by their particular sprayers and settings and how these influence deposition and potential drift. The tool can also be used to determine the effect and importance of adequately selecting, orienting and opening/closing nozzles and optimizing volume application rate and fan speed, in order to adjust the application to the actual vegetation, with the aim of saving resources and reducing risks to humans and the environment. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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23 pages, 23566 KiB

Open AccessArticle

Assessment of Land Consolidation Processes from an Environmental Approach: Considerations Related to the Type of Intervention and the Structure of Farms

by Óscar Ramírez del Palacio, Salvador Hernández-Navarro, Luis Fernando Sánchez-Sastre, Ignacio Alonso Fernández-Coppel and Valentín Pando-Fernández

Agronomy 2022, 12(6), 1424; https://doi.org/10.3390/agronomy12061424 - 13 Jun 2022

Cited by 7 | Viewed by 2353

Abstract

The process of Land Consolidation (LC) is deemed an important instrument of rural development in many countries, where it contributes to the economic development and viability of their rural areas. This paper aims to analyze three areas of Castilla y León in Northwestern [...] Read more.

The process of Land Consolidation (LC) is deemed an important instrument of rural development in many countries, where it contributes to the economic development and viability of their rural areas. This paper aims to analyze three areas of Castilla y León in Northwestern Spain, all having similar agronomic features. The above areas have recently undergone LC processes. This research proves LC can contribute to reducing greenhouse gases (GHG) using the rationalization introduced in the layout of the agrarian exploitations. For this purpose, this paper analyzes the effects of LC actions on the size, shape, and level of scattering of the owners affected and compares the energy consumption in every journey from the exploitation to each plot, as well as the number of row-end turnings within the plots. GHG reductions present significant differences depending on the LC technique carried out, the size of the area consolidated, and the different degrees of intensification of agricultural exploitations. Through the three LC projects analyzed, a reduction in GHG emissions of 23.60% in SA1, 11.46% in SA2, and 9.85% in SA3 would have been obtained. In total, 1067.34 t CO₂ of GHG emissions would have been mitigated. In the light of the results obtained, LC can be considered an efficient process in the strategy of GHG reduction, all in line with the current commitments derived from the Paris Agreement. It is also necessary to continue to research the structure and importance of the consumption of fossil fuels in farming and its possible link to emission reduction policies. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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16 pages, 1686 KiB

Open AccessArticle

Methodological Design to Determine Water Resource Management Indicators in Irrigation Districts

by José Luis Martínez-Tunarroza, Miguel Angel Valenzuela-Mahecha, Andrés F. Rodríguez-Vásquez and Oscar Leonardo García-Navarrete

Agronomy 2022, 12(6), 1407; https://doi.org/10.3390/agronomy12061407 - 11 Jun 2022

Cited by 2 | Viewed by 2357

Abstract

We present the construction of a methodological proposal to determine which indicators should be considered in the monitoring and evaluation of water resource management in the irrigation districts in Colombia (Land Adequacy Districts). This document begins with a characterization of the subsector of [...] Read more.

We present the construction of a methodological proposal to determine which indicators should be considered in the monitoring and evaluation of water resource management in the irrigation districts in Colombia (Land Adequacy Districts). This document begins with a characterization of the subsector of land adequacy, presents the national and international background in the assessment of water resource management, and establishes the optimal scope given the experience of Colombian institutions, the current legal framework, and the quality of official information on subsector issues. Economic, social, water, and climate aspects are considered. Thirteen indicators were chosen from Product Management Indicators, Activity Management Indicators and Results, and Impact Indicators. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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17 pages, 2171 KiB

Open AccessArticle

Ion Exchange Resins to Reduce Boron in Desalinated Seawater for Irrigation in Southeastern Spain

by Alberto Imbernón-Mulero, Belén Gallego-Elvira, Victoriano Martínez-Álvarez, Bernardo Martin-Gorriz, Rubén Molina-del-Toro, Francisco J. Jódar-Conesa and José F. Maestre-Valero

Agronomy 2022, 12(6), 1389; https://doi.org/10.3390/agronomy12061389 - 9 Jun 2022

Cited by 8 | Viewed by 3365

Abstract

Desalinated seawater (DSW) can provide water resources for irrigation in coastal regions where freshwater is scarce. Reverse osmosis (RO) is the most common technique to obtain DSW worldwide. Nevertheless, using DSW for irrigation could pose an agronomic risk as RO permeates may have [...] Read more.

Desalinated seawater (DSW) can provide water resources for irrigation in coastal regions where freshwater is scarce. Reverse osmosis (RO) is the most common technique to obtain DSW worldwide. Nevertheless, using DSW for irrigation could pose an agronomic risk as RO permeates may have a boron concentration above the phytotoxicity thresholds of certain crops, such as woody crops (0.5 to 1.0 mg/L). In this study, an on-farm ion exchange resin system with an average flow of 1 m³/h, designed to reduce the boron concentration of DSW, was evaluated from a technical and economic perspective. The impact of variations in the feed water and operating temperatures on the boron reduction process was assessed. The results show that the system can provide an outflow with a boron concentration below the threshold of 0.5 mg/L over 92 h of operation, with boron rejections of up to 99% during the first 41 h. The estimated cost of boron removal with the on-farm system of the trial was EUR 0.992/m³. However, this cost is expected to decrease to EUR 0.226/m³ for a commercial ion exchange resin (IX) plant (20 m³/h), highlighting the importance of the scale factor. Our results provide novel guidance on the viability of using boron removal IX systems for farms irrigated with DSW, when it is provided by coastal plants with boron concentrations above the crop tolerance. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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10 pages, 1619 KiB

Open AccessArticle

Influence of the Density in Binderless Particleboards Made from Sorghum

by Antonio Ferrandez-Garcia, Maria Teresa Ferrandez-Garcia, Teresa Garcia-Ortuño and Manuel Ferrandez-Villena

Agronomy 2022, 12(6), 1387; https://doi.org/10.3390/agronomy12061387 - 9 Jun 2022

Cited by 6 | Viewed by 2014

Abstract

In order to fight climate change and decouple economic growth from material use, valorization of waste will be fundamental. Sorghum is one of the most important summer crops in the world. The non-edible parts of the plant, the stalks and leaves are left [...] Read more.

In order to fight climate change and decouple economic growth from material use, valorization of waste will be fundamental. Sorghum is one of the most important summer crops in the world. The non-edible parts of the plant, the stalks and leaves are left over and must be disposed of. This work proposes to use sorghum waste particles as a raw material to manufacture boards and analyze the influence of its density. Particles were sprayed with 10% wt of water and placed in a hot press at 2.1 MPa and 110 °C for 30 min. Eight types of panels were produced with densities ranging from 950 kg/m³ to 1250 kg/m³. The results indicated that the water absorption (WA), modulus of rupture (MOR), modulus of elasticity (MOE) and internal bounding strength (IB) depended on the density. With higher densities, the particleboards showed better physical and mechanical behavior. This study demonstrates that it is technically possible to manufacture adhesive-free particleboards from sorghum residues that comply with European standards and can be used as boards for general applications. The use of these particleboards could be beneficial in fighting climate change and in minimizing the use of natural wood. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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6 pages, 470 KiB

Open AccessArticle

Evaluation of Citriculture Mechanisation Level in Valencia Region (Spain): Poll Results

by Coral Ortiz, Antonio Torregrosa and Jose Miguel Martínez

Agronomy 2022, 12(6), 1366; https://doi.org/10.3390/agronomy12061366 - 5 Jun 2022

Cited by 1 | Viewed by 1680

Abstract

The increase of the technology level of citrus production operations is required to improve production profitability and reduce production costs. In the framework of the project CITRUSTECH (“Technological advances for modernisation and sustainability in citrus production”), three different poll questionnaires were developed and [...] Read more.

The increase of the technology level of citrus production operations is required to improve production profitability and reduce production costs. In the framework of the project CITRUSTECH (“Technological advances for modernisation and sustainability in citrus production”), three different poll questionnaires were developed and conducted in the Valencia region to assess the citriculture mechanisation level. In total, 142 questionaries for small and medium-size plantations, 32 for cooperative technicians and 16 for large-size plantations were conducted. From a socioeconomic point of view, clear age and sex inequalities were found. From the technological point of view, relevant differences were found between plantation sizes. The role of the cooperative mechanisation services (custom cost) and other customer services was revealed, with a higher percentage of the area under cultivation at the expense of the small-size plantations. The use of some manual tools was confirmed in pruning, even in large-size orchards. In small-size orchards, the use of backpack sprayers was verified. Regarding farm machinery, besides tractors, hydro-pneumatic sprayers and agricultural shredders were employed. No farm machinery was used during harvesting operations, apart from transport equipment, due to the reduced plantation frames. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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18 pages, 2164 KiB

Open AccessArticle

Sustainable Production of Barley in a Water-Scarce Mediterranean Agroecosystem

by José Antonio Martínez-López, Ramón López-Urrea, Ángel Martínez-Romero, José Jesús Pardo, Jesús Montero and Alfonso Domínguez

Agronomy 2022, 12(6), 1358; https://doi.org/10.3390/agronomy12061358 - 3 Jun 2022

Cited by 5 | Viewed by 2558

Abstract

Scarcity of water resources is one of the main constraints on agricultural activity in arid and semi-arid areas. Despite the great technological development over recent decades, farmers are demanding methodologies and tools adapted to their training, management restrictions, and economic capacity. To tackle [...] Read more.

Scarcity of water resources is one of the main constraints on agricultural activity in arid and semi-arid areas. Despite the great technological development over recent decades, farmers are demanding methodologies and tools adapted to their training, management restrictions, and economic capacity. To tackle these challenges, the sustainable production in water-limited environments of Mediterranean agroecosystems (SUPROMED) project combines, in an online platform, a set of models and methodologies for more efficient management of water, energy, and fertilizers. A two-year trial (2020–2021) was conducted in the Castilla-La Mancha region (Spain) to demonstrate, for a barley crop, the effectiveness of SUPROMED as a farm management support tool. The impact of transferring the model for the economic optimization of irrigation water use at farm level (MOPECO model) irrigation scheduling among other methods and tools, integrated in the SUPROMED platform, to farmers was determined by analyzing a set of productive, economic, and environmental key performance indicators (KPIs). The KPIs were selected to show farmers how the efficient use of productive factors could improve the profitability of their farms, thus reducing the impact of agriculture on the environment. In 2020, the management plan proposed by SUPROMED achieved the same yield as traditional management using 32% less water and resulting in a 13% and 66% improvement in gross margin and gross economic irrigation water productivity, respectively. In 2021, the management implemented by a farmer trained in the use of the tools and methodologies in the SUPROMED platform showed improvements in most of the KPIs analyzed, achieving similar results to those obtained by SUPROMED during 2020. The results are promising, indicating that the tools and models proposed in SUPROMED can be easily used by farmers and can improve the economic and environmental sustainability of Mediterranean agroecosystems. The involvement of public administrations, together with local researchers and technicians, is required for the effective promotion and use of these methodologies by the productive sector. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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10 pages, 2137 KiB

Open AccessArticle

Citrus Fruit Movement Assessment Related to Fruit Damage during Harvesting with an Experimental Low-Frequency–High-Amplitude Device

by Coral Ortiz, Antonio Torregrosa and Sergio Castro-García

Agronomy 2022, 12(6), 1337; https://doi.org/10.3390/agronomy12061337 - 31 May 2022

Cited by 5 | Viewed by 2434

Abstract

The profitability of fresh citrus crops outlines the possibility of using mechanical systems to reduce the high cost of the manual harvesting operation. In this line, an experimental light shaker with low frequency and high amplitude and a hydraulic arm was developed. This [...] Read more.

The profitability of fresh citrus crops outlines the possibility of using mechanical systems to reduce the high cost of the manual harvesting operation. In this line, an experimental light shaker with low frequency and high amplitude and a hydraulic arm was developed. This device had been successfully used for harvesting ornamental citrus trees. In previous studies, it was proven that the removal percentage was adequate, but the percentage of slightly damaged fruit increased compared to a traditional fruit trunk shaker. Visualizing the fruit movements in high-speed video recording images during harvesting, a higher impact level was observed due to the higher amplitude. The aim of this study was to analyze the fruit movement during the vibration with the experimental shaker compared to the movement when vibrating with an orchard tractor mounted trunk shaker related to the increase of slightly damaged fruit when using the experimental shaker. Fruit movement parameters (fruit distance, fruit displacement, speed and acceleration) when using the two harvesting systems (experimental shaker and trunk shaker) were compared analyzing the high-speed video recordings. Results showed that the higher vibration amplitude produced a maximum distance experienced by the fruits (maximum displacement of 0.135 m with the experimental shaker compared to 0.078 m with the trunk shaker) that could cause a higher damage level (74% of slightly damaged fruits using the experiemntal shaker compared to 14% using the trunk shaker). Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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18 pages, 5460 KiB

Open AccessArticle

Values for the Mechanical Properties of Wheat, Maize and Wood Pellets for Use in Silo Load Calculations Involving Numerical Methods

by Manuel Moya, David Sánchez and José Ramón Villar-García

Agronomy 2022, 12(6), 1261; https://doi.org/10.3390/agronomy12061261 - 24 May 2022

Cited by 10 | Viewed by 2548

Abstract

The mechanical properties of the materials stored in agricultural silos determine the loads they generate under static and dynamic conditions. The present work describes the mechanical properties of wheat, maize and wood pellets. Direct shear and triaxial assay devices, and oedometers (all commonly [...] Read more.

The mechanical properties of the materials stored in agricultural silos determine the loads they generate under static and dynamic conditions. The present work describes the mechanical properties of wheat, maize and wood pellets. Direct shear and triaxial assay devices, and oedometers (all commonly used in geotechnical assays), were used to determine these materials’ internal angle of friction, Poisson’s ratio, Young’s modulus, apparent specific weight, etc. The results for wheat and maize were similar to those previously reported by other authors. For the wood pellets, the results for the internal angle of friction and apparent specific weight were also similar to those found in the literature. However, this is a relatively new type of material, and few results of this type have been reported, certainly not enough for reference values to be available. This work is the first to report this material’s dilatancy angle and Poisson’s ratio. A table is provided with suggested reference values for the studied mechanical properties of each of the test materials; these can be used in silo load calculations involving numerical methods. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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15 pages, 3139 KiB

Open AccessArticle

Optimal Irrigation Scheduling for Greenhouse Tomato Crop (Solanum Lycopersicum L.) in Ecuador

by Javier Ezcequiel Colimba-Limaico, Sergio Zubelzu-Minguez and Leonor Rodríguez-Sinobas

Agronomy 2022, 12(5), 1020; https://doi.org/10.3390/agronomy12051020 - 24 Apr 2022

Cited by 13 | Viewed by 4679

Abstract

Tomato crop is grown worldwide and is considered a mass consumer product. In Ecuador, tomato growers face two major issues: water scarcity and water mismanagement, which cause a reduction in the framers’ gross income and ecosystem services. This paper is aimed at finding [...] Read more.

Tomato crop is grown worldwide and is considered a mass consumer product. In Ecuador, tomato growers face two major issues: water scarcity and water mismanagement, which cause a reduction in the framers’ gross income and ecosystem services. This paper is aimed at finding an optimal irrigation scheduling in greenhouse tomato crop to achieve a balance among production, fruit quality and water use efficiency. Thus, two experiments were settled. In the first experiment, four water doses (80, 100, 120 and 140% ETc) and two irrigation frequencies (one and two irrigations per day) were compared. The second experiment evaluated the two best water doses of the first one (100 and 120% ETc) and four irrigation frequencies (one and two irrigations per day, one irrigation every two days, one irrigation every three days). Each experiment monitored the variables for tomato production (plant height, stem diameter, fruits per plant, yield) and tomato quality (pH, total soluble solids, titratable acidity). The study concluded that water doses affected more than irrigation frequency to fruit quality and production. The dose of 100% ETc, applied in one irrigation per day, is suggested to obtain a balance between production, fruit quality and water use efficiency. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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13 pages, 23510 KiB

Open AccessArticle

Influence of the New Energy Context on the Spanish Agri-Food Industry

by José L. García, Alicia Perdigones, Rosa M. Benavente and Fernando R. Mazarrón

Agronomy 2022, 12(4), 977; https://doi.org/10.3390/agronomy12040977 - 18 Apr 2022

Cited by 5 | Viewed by 2940

Abstract

The Spanish agri-food industries face a new energy context radically different from the one existing less than a year ago. A comparable situation is occurring in other European countries. The great variability and different seasonality of the agro-industries condition the adaptation measures to [...] Read more.

The Spanish agri-food industries face a new energy context radically different from the one existing less than a year ago. A comparable situation is occurring in other European countries. The great variability and different seasonality of the agro-industries condition the adaptation measures to be implemented. This article quantifies the impact of the new energy context on real industries with quite different consumption patterns. More than 1000 scenarios have been analysed to determine the effectiveness of adaptation measures. The study results demonstrate the critical situation to which the sector is subjected. The new tariff system affects the agri-food sector in an unequal way, benefiting industries with marked seasonality. In just one year, the electricity bill has increased between 62% and 151%. The savings generated by implementing measures such as optimising contracted power to a new hourly discrimination system (up to 6%) or shifting consumption to lower-cost periods (up to 21%) do not seem sufficient. If prices do not fall drastically, immediate installation of generation systems, such as photovoltaic panels, appears essential to maintain the viability and competitiveness of the sector. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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13 pages, 1958 KiB

Open AccessArticle

Technical Inspections of Agricultural Machinery and Their Influence on Environmental Impact

by Efrén Tarancón-Andrés, Jacinto Santamaria-Peña, David Arancón-Pérez, Eduardo Martínez-Cámara and Julio Blanco-Fernández

Agronomy 2022, 12(4), 907; https://doi.org/10.3390/agronomy12040907 - 9 Apr 2022

Cited by 2 | Viewed by 2160

Abstract

On 20 May 2018, Royal Decree 920/2017, establishing the minimum requirements for the regime of the vehicle technical inspection (ITV in Spanish) to circulate on public roads, entered into force. The new regulations are aimed at ensuring that vehicles in general, and agricultural [...] Read more.

On 20 May 2018, Royal Decree 920/2017, establishing the minimum requirements for the regime of the vehicle technical inspection (ITV in Spanish) to circulate on public roads, entered into force. The new regulations are aimed at ensuring that vehicles in general, and agricultural vehicles in particular, are in proper condition from the point of view of safety and environment. In La Rioja, detailed data are available on the technical inspections performed on agricultural machinery for the last 15 years (2005–2020). The aim of this paper is to analyze the possible effects of technical inspections of agricultural vehicles on their environmental impact. Emissions regulations for this type of vehicle have evolved over the last few years, and as a result, new tractors have better environmental performance. Considering that serious defects detected in vehicle technical inspections can lead the owner to replace the vehicle with a new one, there is a potential reduction in the environmental impact associated with ITVs, as studied in this paper. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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19 pages, 4474 KiB

Open AccessArticle

Antifungal Activity of Methylxanthines against Grapevine Trunk Diseases

by Eva Sánchez-Hernández, Celia Andrés-Juan, Laura Buzón-Durán, Adriana Correa-Guimaraes, Jesús Martín-Gil and Pablo Martín-Ramos

Agronomy 2022, 12(4), 885; https://doi.org/10.3390/agronomy12040885 - 6 Apr 2022

Cited by 5 | Viewed by 3081

Abstract

Methylxanthines, found in the seeds, leaves, and fruits of some plants, are receiving increasing attention as promising treatments for wood-degrading fungi. The aim of the study presented herein was to explore the potential applications of caffeine, four caffeine derivatives (viz. 8-bromo-caffeine, 8-iodo-caffeine, 8-(4-fluorophenoxy)-caffeine, [...] Read more.

Methylxanthines, found in the seeds, leaves, and fruits of some plants, are receiving increasing attention as promising treatments for wood-degrading fungi. The aim of the study presented herein was to explore the potential applications of caffeine, four caffeine derivatives (viz. 8-bromo-caffeine, 8-iodo-caffeine, 8-(4-fluorophenoxy)-caffeine, and 8-(2,3,5,6-tetrafluoroalcoxy)-caffeine), and theophylline as antifungals for Botryosphaeriaceae species associated with grapevine trunk diseases (GTDs). In vitro susceptibility tests were conducted to assess the antimycotic activity of the aforementioned compounds and their conjugated complexes with chitosan oligomers (COS). Caffeine, Br-caffeine, and I-caffeine exhibited higher efficacies than imidazole, the chosen antifungal control. Moreover, a strong synergistic behavior between COS and the methylxanthine derivatives was observed. The COS–I-caffeine complex showed the best overall performance against the phytopathogenic fungi with EC₉₀ values of 471, 640, and 935 µg mL⁻¹ for D. seriata, D. viticola, and N. parvum, respectively. In a second step, combinations of the new treatments with imidazole were also explored, resulting in further activity enhancement and EC₉₀ values of 425, 271, and 509 mL⁻¹ against D. seriata, D. viticola, and N. parvum, respectively, for the COS–I-caffeine-imidazole ternary compound. Given the high in vitro efficacy of these formulations for the control of GTDs, they may deserve further investigation with in vivo and field bioassays as an alternative to conventional fungicides. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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14 pages, 3219 KiB

Open AccessArticle

Effect of the Hopper Angle of a Silo on the Vertical Stress at the Cylinder-to-Hopper Transition

by Rômulo Marçal Gandia, Wisner Coimbra de Paula, Estácio Antunes de Oliveira Junior, Gerardo Hernández Rodrigo, Ángel Ruiz Padín, Alberto Tascón Vegas, Francisco Carlos Gomes and Pedro José Aguado Rodríguez

Agronomy 2022, 12(4), 830; https://doi.org/10.3390/agronomy12040830 - 29 Mar 2022

Cited by 5 | Viewed by 4222

Abstract

Silos are used worldwide to store granular and powdered materials. Agricultural, food and feed products are commonly stored in silos. However, many questions remain unanswered about how to estimate the pressures applied by the bulk material, which are needed to design and calculate [...] Read more.

Silos are used worldwide to store granular and powdered materials. Agricultural, food and feed products are commonly stored in silos. However, many questions remain unanswered about how to estimate the pressures applied by the bulk material, which are needed to design and calculate the structure of the silo. The complexity of the laws that govern the mechanical behavior of the stored material along with the low number of experimental stations in the world hinder progress in this field. The aim of this study was to elucidate the relationship of the hopper angle, flow pattern and vertical stress at the cylinder-to-hopper transition in slender silos. Therefore, a set of experiments was conducted on a test station to measure the vertical stress produced by maize at the cylinder-to-hopper transition. Five different hopper angles were used. The experiments comprised the filling, the static phase and the discharge. The results obtained show that the hopper angle influences the vertical stress at the cylinder-to-hopper transition. Some bottom configurations (flat bottom and bottom with an angle of 30°) led to vertical stresses that exceeded the value calculated according to Eurocode 1. It is clear that further experimental studies are still necessary to understand the underlying physical phenomena and the relations between pressures, silo geometry and flow pattern of the stored material. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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20 pages, 34240 KiB

Open AccessArticle

Management Zones in Pastures Based on Soil Apparent Electrical Conductivity and Altitude: NDVI, Soil and Biomass Sampling Validation

by João Serrano, Shakib Shahidian, Luís Paixão, José Marques da Silva and Francisco Moral

Agronomy 2022, 12(4), 778; https://doi.org/10.3390/agronomy12040778 - 23 Mar 2022

Cited by 13 | Viewed by 2933

Abstract

The intensification of the Montado mixed ecosystem (agro–silvo–pastoral) is a current endeavor in the context of promoting the sustainability of extensive livestock production in the Mediterranean region. Increased pasture productivity and extensive animal production involves the use of technologies to monitor spatial variability [...] Read more.

The intensification of the Montado mixed ecosystem (agro–silvo–pastoral) is a current endeavor in the context of promoting the sustainability of extensive livestock production in the Mediterranean region. Increased pasture productivity and extensive animal production involves the use of technologies to monitor spatial variability and to implement differentiated management of pasture grazing, fertilization or soil amendment. An intermediate step should lead to the identification and demarcation of areas with similar characteristics (soil and/or crop development), known as homogeneous management zones (HMZ) to implement site-specific management strategies. In this study, soil apparent electrical conductivity (EC_a) and altimetry surveys were carried out in six experimental pasture fields with a non-contact electromagnetic induction sensor (EM38) associated with a Global Navigation Satellite System (GNSS) receiver. These EC_a and topographic maps were used in geostatistical analyses for designing and establishing final classification maps with three HMZ (less, intermediate and more potential). The normalized difference vegetation index (NDVI), obtained from a proximal optical sensor, and soil and biomass sampling were used to validate these HMZ. From a practical perspective, these HMZ are the basis for preparation of fertilizer prescription maps and use of variable rate technology (VRT) in a Precision Agriculture project. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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23 pages, 6524 KiB

Open AccessArticle

Decision Pattern for Changing Polluted Areas into Recreational Places

by Alfonso Parra, Encarnación Conesa, Raúl Zornoza, Ángel Faz and María Dolores Gómez-López

Agronomy 2022, 12(4), 775; https://doi.org/10.3390/agronomy12040775 - 23 Mar 2022

Cited by 4 | Viewed by 1923

Abstract

There are many enclaves in the Mediterranean basin with soils contaminated with heavy metal(loid)s, most of these in natural areas of great beauty that have suffered the consequences of industrial and mining activity for years. These soils pose a risk to human and [...] Read more.

There are many enclaves in the Mediterranean basin with soils contaminated with heavy metal(loid)s, most of these in natural areas of great beauty that have suffered the consequences of industrial and mining activity for years. These soils pose a risk to human and animal health due to the transfer of metal(loid)s condemning these areas to isolation. The rehabilitation by means of phytoremediation is one of the most used techniques, but phytoremediation must be part of a comprehensive strategy of steps that guide owners and administrations in the recovery of ecosystem services. An easily replicable decision-making methodology is defined, considering the initial conditions, the preferences of the decision makers or typologies from among six possibilities and the different models of use, typified in 13 categories. As a result, a landscape is obtained that integrates phytostabilization and areas with recreational and/or educational uses. Two case studies from the southeast of Spain are presented as validation, a deposit of mining sludge residues and the channel of a river contaminated by industrial discharges. Both enclaves are included in the tourist and cultural offer of their area, thus achieving an environmental and socioeconomic benefit and have been visited by more than 1000 people in a two-year period. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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16 pages, 3755 KiB

Open AccessArticle

Prediction Model of Photovoltaic Power in Solar Pumping Systems Based on Artificial Intelligence

by Jorge Cervera-Gascó, Rafael González Perea, Jesús Montero and Miguel A. Moreno

Agronomy 2022, 12(3), 693; https://doi.org/10.3390/agronomy12030693 - 13 Mar 2022

Cited by 9 | Viewed by 3072

Abstract

Photovoltaic solar energy is becoming very important globally due the benefits of their use. Climate change is resulting in frequent climatic variations that have a direct effect on the energy production in photovoltaic installations, so their good management is essential. This can be [...] Read more.

Photovoltaic solar energy is becoming very important globally due the benefits of their use. Climate change is resulting in frequent climatic variations that have a direct effect on the energy production in photovoltaic installations, so their good management is essential. This can be a big problem, for example, in photovoltaic pumping systems where irrigated crops can be affected due to lack of water. In this work, a PREPOSOL (PREdiction of POwer in SOLar installations) model was developed in MATLAB^® software, which allowed to predict the power generated in the photovoltaic installations up to 3 h in advance using Artificial Neural Networks (ANNs) in a Bayesian framework with Genetic Algorithms. Despite that the PREPOSOL model can be implemented for other activities with photovoltaic solar energy, in this case, it was applied to photovoltaic pumping systems. The results showed that the model estimated the generated power with a relative error (RE) and R² of 8.10 and 0.9157, respectively. Moreover, a representative example concerning irrigation programming is presented, which allowed adequate management. The methodology was calibrated and validated in a high-power and complex photovoltaic pumping system in Albacete, Spain. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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13 pages, 847 KiB

Open AccessArticle

Chitosan-Based Bioactive Formulations for the Control of Powdery Mildew in Viticulture

by David Ruano-Rosa, Eva Sánchez-Hernández, Rubén Baquero-Foz, Pablo Martín-Ramos, Jesús Martín-Gil, Sergio Torres-Sánchez and José Casanova-Gascón

Agronomy 2022, 12(2), 495; https://doi.org/10.3390/agronomy12020495 - 16 Feb 2022

Cited by 16 | Viewed by 3794

Abstract

Grapevine is highly susceptible to fungal diseases, whose incidence and severity increase due to climate change. The present work focuses on the assessment of eight combinations of natural products with chitosan oligomers with fungicidal capacity that may be effective in the integrated control [...] Read more.

Grapevine is highly susceptible to fungal diseases, whose incidence and severity increase due to climate change. The present work focuses on the assessment of eight combinations of natural products with chitosan oligomers with fungicidal capacity that may be effective in the integrated control of powdery mildew, in compliance with Article 14 of the European Directive 2009/128/EC. Their efficacy was evaluated in field conditions against natural infections, in a plot with high disease pressure during a growing season (assaying both foliar or root application), and against overwintering inoculums (chasmothecia) through in vitro tests. In addition, their possible biostimulant capacities were evaluated based on harvest yields. Treatments based on chitosan oligomers in combination with secondary metabolites of Streptomyces spp. and chitosan oligomers combined with hydrolyzed gluten showed the best results in terms of disease control. Given the high efficacy of these formulations, comparable to that of conventional antifungals, they constitute an interesting alternative for the control of this disease whose treatment can, in some cases, represent almost half of the production costs. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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16 pages, 3119 KiB

Open AccessEditor’s ChoiceArticle

Lignin–Chitosan Nanocarriers for the Delivery of Bioactive Natural Products against Wood-Decay Phytopathogens

by Eva Sánchez-Hernández, Natalia Langa-Lomba, Vicente González-García, José Casanova-Gascón, Jesús Martín-Gil, Alberto Santiago-Aliste, Sergio Torres-Sánchez and Pablo Martín-Ramos

Agronomy 2022, 12(2), 461; https://doi.org/10.3390/agronomy12020461 - 12 Feb 2022

Cited by 27 | Viewed by 4238

Abstract

The use of nanocarriers (NCs), i.e., nanomaterials capable of encapsulating drugs and releasing them selectively, is an emerging field in agriculture. In this study, the synthesis, characterization, and in vitro and in vivo testing of biodegradable NCs loaded with natural bioactive products was [...] Read more.

The use of nanocarriers (NCs), i.e., nanomaterials capable of encapsulating drugs and releasing them selectively, is an emerging field in agriculture. In this study, the synthesis, characterization, and in vitro and in vivo testing of biodegradable NCs loaded with natural bioactive products was investigated for the control of certain phytopathogens responsible for wood degradation. In particular, NCs based on methacrylated lignin and chitosan oligomers, loaded with extracts from Rubia tinctorum, Silybum marianum, Equisetum arvense, and Urtica dioica, were first assayed in vitro against Neofusicoccum parvum, an aggressive fungus that causes cankers and diebacks in numerous woody hosts around the world. The in vitro antimicrobial activity of the most effective treatment was further explored against another fungal pathogen and two bacteria related to trunk diseases: Diplodia seriata, Xylophilus ampelinus, and Pseudomonas syringae pv. syringae, respectively. Subsequently, it was evaluated in field conditions, in which it was applied by endotherapy for the control of grapevine trunk diseases. In the in vitro mycelial growth inhibition tests, the NCs loaded with R. tinctorum resulted in EC₉₀ concentrations of 65.8 and 91.0 μg·mL⁻¹ against N. parvum and D. seriata, respectively. Concerning their antibacterial activity, a minimum inhibitory concentration of 37.5 μg·mL⁻¹ was obtained for this treatment against both phytopathogens. Upon application via endotherapy on 20-year-old grapevines with clear esca and Botryosphaeria decay symptoms, no phytotoxicity effects were observed (according to SPAD and chlorophyll fluorescence measurements) and the sugar content of the grape juice was not affected either. Nonetheless, the treatment led to a noticeable decrease in foliar symptoms as well as a higher yield in the treated arms as compared to the control arms (3177 vs. 1932 g/arm), suggestive of high efficacy. Given the advantages in terms of controlled release and antimicrobial product savings, these biodegradable NCs loaded with natural extracts may deserve further research in large-scale field tests. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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13 pages, 3581 KiB

Open AccessArticle

Determination of the Angle of Repose and Coefficient of Rolling Friction for Wood Pellets

by Marcos A. Madrid, José M. Fuentes, Francisco Ayuga and Eutiquio Gallego

Agronomy 2022, 12(2), 424; https://doi.org/10.3390/agronomy12020424 - 8 Feb 2022

Cited by 13 | Viewed by 6084

Abstract

The determination of the angle of repose for granular materials is indispensable for their handling and the design of containers and technological processing equipment. On the other hand, computational simulations have become an essential tool to understand the micro-behavior of the granular material [...] Read more.

The determination of the angle of repose for granular materials is indispensable for their handling and the design of containers and technological processing equipment. On the other hand, computational simulations have become an essential tool to understand the micro-behavior of the granular material and to relate it with the macro-behavior. The experimental determination of the angle of repose has a fundamental role when defining the required parameters to perform realistic simulations. However, there is a lack of a standard that allows the reproducibility of the experiments when using granular materials of equivalent spherical radius greater than 2 mm, such as corn, soybeans, wheat and PLA pellets, among others. In particular, a product of growing importance in the global strategy of decarbonization of the economy is biomass pellets, whose handling operations are one of the main components for the total cost of pellets supplied to the final user. In the present work, with the aim of determining the rolling friction coefficient, the variations in the angle of repose with the drop height for biomass pellets were studied both experimentally and with simulations, and an optimal procedure for its determination was found. Then, a calibration of the coefficient of rolling friction was performed through computational simulations using the discrete element method. The accuracy of the model under different configurations was checked. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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15 pages, 1588 KiB

Open AccessArticle

Potential of Native Trichoderma Strains as Antagonists for the Control of Fungal Wood Pathologies in Young Grapevine Plants

by Natalia Langa-Lomba, Pablo Martín-Ramos, José Casanova-Gascón, Carmen Julián-Lagunas and Vicente González-García

Agronomy 2022, 12(2), 336; https://doi.org/10.3390/agronomy12020336 - 28 Jan 2022

Cited by 13 | Viewed by 3322

Abstract

Neofusicoccum parvum and Rhizoctonia solani are fungal pathogens with an increasing incidence in young grapevine plants. In this study, the antagonistic potential of some strains of the genus Trichoderma isolated from grapevine against these pathogens was investigated at the laboratory and greenhouse levels. [...] Read more.

Neofusicoccum parvum and Rhizoctonia solani are fungal pathogens with an increasing incidence in young grapevine plants. In this study, the antagonistic potential of some strains of the genus Trichoderma isolated from grapevine against these pathogens was investigated at the laboratory and greenhouse levels. In-plate confrontation assays showed that the selected Trichoderma strains could inhibit the mycelial growth of both taxa, being more effective against N. parvum. In the in vivo assays, the biocontrol activity of the mentioned strains against the pathogens, when applied either simultaneously or successively, was tested on both grafted plants and seedlings germinated from seed. The effectiveness of the treatments was evaluated by comparing biomass weight and vascular rot lengths data. In seedling trials, successive treatments resulted in higher root development and a lower colonization rate of the pathogens, especially against R. solani. In grafted plants, some disparity was observed against N. parvum: simultaneous treatments resulted in higher aerial biomass, but successive treatments resulted in higher root biomass and lower necrosis. Against R. solani, simultaneous treatments were clearly more effective, with higher root and aerial length values and lower necrosis. The obtained data suggest that the use of Trichoderma spp. isolates can constitute an alternative to conventional fungicides to control certain grapevine wood diseases. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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13 pages, 3017 KiB

Open AccessArticle

Analysis of the Manufacturing Variables of Binderless Panels Made of Leaves of Olive Tree (Olea europaea L.) Pruning Waste

by Antonio Ferrandez-Garcia, Maria Teresa Ferrandez-Garcia, Teresa Garcia Ortuño, Francisco Mata-Cabrera and Manuel Ferrandez-Villena

Agronomy 2022, 12(1), 93; https://doi.org/10.3390/agronomy12010093 - 30 Dec 2021

Cited by 7 | Viewed by 2274

Abstract

While the construction industry consumes more raw materials than any other industrial sector, agriculture generates a large amount of waste that is not managed properly. The olive industry produces more than 7.5 million tons of waste that could be recovered. This paper presents [...] Read more.

While the construction industry consumes more raw materials than any other industrial sector, agriculture generates a large amount of waste that is not managed properly. The olive industry produces more than 7.5 million tons of waste that could be recovered. This paper presents a new method to valorize the leaves of olive tree pruning waste consisting of the manufacture of ecologic boards without adhesives by hot pressing. In order to analyze their influence, three manufacturing variables were varied to obtain the boards: leaf type (shredded and whole leaves), temperature (130, 140 and 150 °C) and time (4, and 12 min). Twenty-four boards were made and were then tested for their mechanical, physical and thermal properties according to the EN standards. The boards showed good results of thickness swelling (TS), water absorption (WA) and of thermal conductivity and can be used as an alternative for manufacturing thermal insulation boards. With a smaller particle size of shredded leaves, longer pressing times and higher pressing temperatures, the mechanical behavior of the boards could improve. The olive leaves are a low-cost renewable resource, and manufacturing products with a long, useful life can be beneficial to the environment. Full article

(This article belongs to the Special Issue Selected Papers from 11th Iberian Agroengineering Congress)

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