Effects of regulated deficit irrigation on physiology, yield and fruit quality in apricot trees under Mediterranean conditions

Scarce water resources mainly in arid and semi-arid areas have caused an increasing interest for applying irrigation protocols aiming to reduce water spends. The effects of regulated deficit irrigation (RDI) on the performance of apricot trees (Prunus armeniaca L. cv. “Búlida”) were assessed in Murcia (SE Spain), during three consecutive growing seasons (2008-2010). The hypothesis was that RDI would not restrict yield but increase fruit quality while saving water. Two irrigation treatments were established: i) control, irrigated to fully satisfy crop water requirements (100% ETc) and ii) RDI, that reduced the amount of applied water to: a) 40% of ETc at flowering and stage I of fruit growth; b) 60% of ETc during the stage II of fruit growth and c) 50% and 25% of ETc during the late postharvest period (from 60 days after harvest). Stem water potential, gas exchanges, trunk cross-sectional area (TCSA), fruit diameter, yield and fruit quality traits were determined. Vegetative growth was decreased by the use of RDI (12% less TCSA on average for the three years), whereas yield was unaffected. In addition, some qualitative characteristics of the fruits, such as the level of soluble solids, sweetness/acidity relation and fruit colour, were improved by the use of RDI. These results and average water savings of approximately 30%, lead us to conclude that RDI strategies are a possible solution for irrigation management in areas with water shortages, such as arid and semi-arid environments

Challenges of viticulture adaptation to global change: tackling the issue from the roots

Viticulture is facing emerging challenges not only because of the effect of climate change on yield and composition of grapes, but also of a social demand for environmental-friendly agricultural management. Adaptation to these challenges is essential to guarantee the sustainability of viticulture. The aim of this review is to present adaptation possibilities from the soil-hidden, and often disregarded, part of the grapevine, the roots. The complexity of soil-root interactions makes necessary a comprehensive approach taking into account physiology, pathology and genetics, in order to outline strategies to improve viticulture adaptation to current and future threats. Rootstocks are the link between soil and scion in grafted crops, and they have played an essential role in viticulture since the introduction of phylloxera into Europe at the end of the 19th century. This review outlines current and future challenges that are threatening the sustainability of the wine sector and the relevant role that rootstocks can play to face these threats. We describe how rootstocks along with soil management can be exploited as an essential tool to deal with the effects of climate change and of emerging soil-borne pests and pathogens. Moreover, we discuss the possibilities and limitations of diverse genetic strategies for rootstock breeding.This work is framed in the networking activities of RedVitis (AGL2015-70931-REDT) and RedVitis 2.0 (AGL2017-90759-REDT), funded by the State Research Agency (AEI) of the Spanish Ministry of Science and Innovation. Ms Diana Marin is beneficiary of postgraduate scholarship funded by Universidad Publica de Navarra (FPI-UPNA-2016). Dr Juan Emilio Palomares-Rius acknowledges the State Research Agency (AEI) of the Spanish Ministry of Science and Innovation for the 'Ramon y Cajal' Fellowship RYC-2017-22228 and Dr David Gramaje acknowledges Spanish Ministry of Economy and Competitiveness for the 'Ramon y Cajal' Fellowship RYC-2017-23098

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

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

Cultivos de soja, frijol y maíz y consorcio de maíz y frijol bajo siembra directa: pérdidas de suelo y agua por erosión hídrica bajo lluvia simulada en Lages, SC, Brasil.

Diferentes sistemas de manejo dei sualo resultantes de dirferentes cultivos pueden provocar que el suelo está más o menos sujeto a la erosíon.Resumo expandido

Decision support system for selecting the rootstock, irrigation regime and nitrogen fertilization in winemaking vineyards: WANUGRAPE4.0

We aim to develop and transfer to the wine sector a decision support system (DSS) in the frame of WANEGRAPE4.0 project that, integrated into a geographic information system, helps wine growers in i) selecting the most suitable rootstock given some agroecological conditions and oenological objectives; and ii) managing irrigation and nitrogen fertilization in the most suitable way for the selected rootstock and agroecological conditions. The following goals have been achieved. First, the modular structure and information flow of the DSS has been defined. Second, the main algorithms of the water balance module (DSS core part) have been formulated and the module coded in a spreadsheet. Third, this water balance module has been tested with data from field experiments in several regions of Spain. Fourth, the relationships between grapevine water status and production and harvest quality variables have been established, revealing an always-significant effects of the decrease in water stress on vegetative development, yield, and grape composition. Fifth, the nitrogen fertilizer effects on vine performance has been assessed. Sixth, the effects rootstocks have on 5 parameters of vine production and grape quality for winemaking have been established too by doing another meta-analysis of rootstock trials. Seventh, a rootstock selection module has been defined. The WANUGRAPE4.0 project goes on with the integration of all its modules, their coding in a World Wide Web language and their publication on an Internet portal

Estimation of the daily water consumption by maize under Atlantic climatic conditions (A Coruña, NW Spain) using Frequency Domain Reflectometry – a case study

Climatic variables and soil present a high spatio-temporal variability. Evapotranspiration estimations based on climatic variables may be inadequate for assessing soil water content in the root-influenced zone and/or soil water consumption by plants. Other methods may provide better estimates of this water consumption. The aim of this study was to quantify the soil moisture dynamics in the root-influenced zone and to assess the daily water consumption by the crop using Frequency Domain Reflectometry (FDR). The studied site is located in A Coruña (Spain). The study was carried out from June to October in 2008 and 2009, in a maize (<i>Zea mays</i>, L.) field on a silt-clay textured soil. Evapotranspiration was estimated by the Penman-Monteith equation using meteorological data from a station located on the experimental site. Soil water content in the root-influenced zone (0–60 cm depth) was hourly monitored each 20 cm (0–20 cm, 20–40 cm, and 40–60 cm) using FDR. Evaluations were performed on days with slight or no rainfall. During the study period, the magnitude of the diurnal soil water loss was more evident in the first layer (0–20 cm depth) and less important in the subsequent soil layers. The greatest consumption occurred between 14 and 19 h, up to 53.64% of the total. Overall, daily water consumption increased significantly with soil water content (p-value < 0.001). In general, water losses from the 0–20 cm soil layer were greater than in subsoil horizons due to maize water-uptake and evaporation. In contrast, water content in the deepest part of the soil profile was close to saturation, even on the driest days of the studied period. Evapotranspiration overestimate maize water requirements as its values were greater than those measured with the probe. In conclusion, FDR allows a more accurate estimation of the soil water balance. Therefore, monitoring soil water content would be useful in the assessment of saturation risks or water stress (drought), thus aiding in the decision making, for instance, in irrigation management. Results from this study may help to improve irrigation practices in humid zones

Effects of different soil tillage systems and coverages on soybean crop

Abstract Nowadays, agricultural practices should combine high yields with a sustainable use of resources. Different tillage practices and crop covers, if combined, may help to achieve both objectives. In this work, several traits of a soybean (Glycine max L. Merr) cultivar were studied under different conditions of tillage and previous soil coverages. The experiment was installed at Lageado Research Station, Botucatu county, SP, Brazil, on a Paleudult. It consisted of nine treatments (combining three systems of soil tillage and three cover crops) and 4 replicates, yielding 36 plots of a randomized block experimental design. The soil tillage systems considered were: (i) conventional tillage with two heavy harrowing and a levelling harrowing; (ii) chiseling, and (iii) no-tillage with chemical drying of vegetation. The three cover crops used were: black oat, sorghum and spontaneous vegetation. Analyzed variables were: plant height, initial and final plant densities, height of first pod insertion, weight of a thousand grains, number of pods per plant, number of grains per pod, and crop yield. No significant differences were observed for most of the analyzed variables; however, conventional tillage produced significantly heavier grains and a higher number of pods per plant. The selected covers were considered an excellent coverage prior to planting soybean in a crop rotation. The three tillage systems can be used for deployment of culture without compromising the development of soybean. Additional key words: black oat, chisel, Glycine max, heavy harrow, sorghum, yield. Resumen Efectos de diferentes sistemas de laboreo del suelo y coberturas vegetales sobre la cosecha de soja en la región de Botucatu en Brasil Actualmente, las prácticas agrícolas deben combinar elevadas productividades con un uso sostenible de los recursos. Diferentes sistemas de laboreo y coberturas vegetales, combinados, pueden ayudar a conseguir ambos objetivos. En este trabajo se han estudiado diversos aspectos de un cultivar de soja (Glycine max L. Merr) sometido a diferentes condiciones de laboreo y cobertura vegetal. El experimento se llevó a cabo en la Estación Experimental de Lageado, Botucatu (São Paulo, Brasil) sobre un Paleudult, y constó de nueve tratamientos (tres sistemas de laboreo y tres coberturas vegetales combinados) y cuatro repeticiones, totalizando 36 parcelas con un diseño experimental en bloques aleatorios. Los sistemas de laboreo considerados fueron (i) laboreo convencional con dos gradas pesadas y una niveladora; (ii) escarificado y (iii) no laboreo con desecación química de la vegetación. Las tres coberturas utilizadas fueron la avena negra, el sorgo y la vegetación espontánea. Las variables analizadas fueron altura de las plantas, densidad inicial y final de plantas, altura de la inserción de la primera vaina, peso de mil granos, número de vainas por planta y de granos por vaina y productividad de la cosecha. No se observaron diferencias significativas en la mayoría de las variables; sin embargo, el laboreo convencional produjo granos significativamente más pesados y un mayor número de vainas por planta. Las coberturas seleccionadas se consideraron excelentes previas a la plantación de soja en una rotación de cultivos. Los tres sistemas de laboreo pueden implementar el cultivo sin comprometer el desarrollo de la soja

Efectos del laboreo en el desarrollo de varios cultivares de algodón en el sudoeste de Bahía, Brasil

Cotton (Gossypium hirsutum L.r. latifolium Hutch) is very sensitive to soil conditions. The Iuiu Valley, located in the Southwest of Bahia State in Brazil, was an important area for cotton production but an inadequate soil management for years and consequent soil quality degradation lead to the decline of the crop in the region. In an effort to reestablish cotton, this study was carried out to identify a sustainable soil management system for cotton production in the region. The experiment was carried out in Palmas de Monte Alto (Bahia, Brazil) on an Eutrichrept soil, and consisted of eight treatments (two tillage systems and four cotton cultivars). The field lay-out was a split-plot with tillage systems as main plots and cultivars as subplots. The tillage systems consisted of conventional and reduced tillage and cotton cultivars used were 'BRS Aroeira', 'BRS 201', 'Delta Opal' and 'BRS Cedro'. No significant differences were observed between the two tillage systems for plant height, stem diameter, boll weight, yield, fiber percentage, and fiber length. Conventional tillage promoted higher fiber length and uniformity for BRS 201 as well as higher fiber resistance for the other three cultivars. On the other hand, reduced tillage promoted higher micronaire index values for Delta Opal. The BRS Cedro cultivar showed a greater plant height independently from the tillage system. In conclusion, reduced tillage allowed a sustainable soil management without compromising cotton yields and quality.El algodonero (Gossypium hirsutum L.r. latifolium Hutch) es muy sensible a las condiciones del suelo. El Valle del Iuiu, localizado al suroeste del estado de Bahía en Brasil, se destaca como una importante zona productora de algodón, pero el inadecuado sistema de manejo del suelo durante años y la consiguiente degradación de la calidad del suelo han ocasionado el declive de este cultivo en la región. En un esfuerzo por reestablecer este cultivo, se realizó un estudio para identificar un sistema de manejo del suelo sostenible para la producción de algodón en la región. El experimento se llevó a cabo en Palmas de Monte Alto (Bahía, Brasil) sobre un Eutrochrept, y constó de ocho tratamientos (dos sistemas de laboreo y cuatro cultivares de algodón) en un diseño experimental en bloques aleatorios, en esquema de parcela subdividida. Los sistemas de laboreo consistieron en un laboreo convencional y un laboreo reducido y los cuatro cultivares utilizados fueron 'BRS Aroeira', 'BRS 201', 'Delta Opal' y 'BRS Cedro'. No se observaron diferencias significativas entre los dos sistemas de laboreo para la altura de plantas, diámetro del tallo, masa de capullos, productividad, porcentaje y longitud de fibras. El laboreo convencional promovió unas mayores longitud y uniformidad de fibras para BRS 201, así como una mayor resistencia de fibras para los otros tres cultivares. Por otra parte, el laboreo reducido proporcionó mayores valores de índice de micronaire para Delta Opal. BRS Cedro presentó una mayor altura de plantas, independientemente del sistema de laboreo. En conclusión, el laboreo reducido permitió un manejo sostenible del suelo sin detrimento de la producción de algodón ni de su calidad

Multifractal behaviour of the soil water content of a vineyard in northwest Spain during two growing seasons

Soil processes are characterized by a great degree of heterogeneity, which may be assessed by scaling properties. The aims of the current study were to describe the dynamics of soil water content at three depths in a vineyard under rain-fed and irrigation conditions and to assess the multifractality of these time data series. Frequency domain reflectometry (FDR) sensors were used for automatically monitoring soil water content in a vineyard located in Leiro (Ourense, northwest Spain). Data were registered at 30 min intervals at three depths (20, 40, and 60 cm) between 14 June and 26 August 2011 and 2012. Two treatments were considered: rain-fed and irrigation to 50 % crop evapotranspiration. Soil water content data series obeyed power laws and tended to behave as multifractals. Values for entropy (<i>D</i>₁) and correlation (<i>D</i>₂) dimensions were lower in the series from the irrigation treatment. The Hölder exponent of order zero (<i>α</i>₀) was similar between treatments; however, the widths of the singularity spectra, <i>f</i>(<i>α</i>), were greater under irrigation conditions. Multifractality indices slightly decreased with depth. These results suggest that singularity and Rényi spectra were useful for characterizing the time variability of soil water content, distinguishing patterns among series registered under rain-fed and irrigation treatments