Water Uptake and Germination of Caper (Capparis spinosa L.) Seeds

[EN] Caper is a perennial deciduous sub-shrub that grows in almost all circum-Mediterranean countries. The specialized literature presents three possible dormancy types that can cause low germination of caper seeds: Physiological dormancy (PD), physical dormancy (PY), and combinational dormancy (PY + PD). We conducted three experiments to analyze the imbibition, viability, and germination of seeds of different ages, provenances, and the level of deterioration of the seed cover. None of the commercialized lots of standard seeds tested exceeded 6% germination, nor 35% viability, while the owned seeds reached 90% in both parameters, indicating that all viable seeds germinated. The seed moisture content along the soaking period followed the first two phases of the typical triphasic model of water uptake in seed germination: The imbibition and lag phases (phase I and II of germination, respectively). Seed hydration began through the hilar region. The fact that all viable owned seeds germinated, together with their moisture content being lower than that of standard seeds, indicated that caper seeds do not have a water-impermeable coat sensu stricto, i.e., they do not show PY; nevertheless, the need to use gibberellic acid to obtain high germination percentages, demonstrated the presence of PD.Foschi, ML.; Juan Ferrer, M.; Pascual España, B.; Pascual-Seva, N. (2020). Water Uptake and Germination of Caper (Capparis spinosa L.) Seeds. Agronomy. 10(6):1-14. https://doi.org/10.3390/agronomy10060838S114106Sonmezdag, A. S., Kelebek, H., & Selli, S. (2019). Characterization of Aroma‐Active Compounds, Phenolics, and Antioxidant Properties in Fresh and Fermented Capers ( Capparis spinosa ) by GC‐MS‐Olfactometry and LC‐DAD‐ESI‐MS/MS. Journal of Food Science, 84(9), 2449-2457. doi:10.1111/1750-3841.14777Wojdyło, A., Nowicka, P., Grimalt, M., Legua, P., Almansa, M. S., Amorós, A., … Hernández, F. (2019). Polyphenol Compounds and Biological Activity of Caper (Capparis spinosa L.) Flowers Buds. Plants, 8(12), 539. doi:10.3390/plants8120539Yahia, Y., Benabderrahim, M. A., Tlili, N., Hannachi, H., Ayadi, L., & Elfalleh, W. (2020). Comparison of Three Extraction Protocols for the Characterization of Caper (Capparis spinosa L.) Leaf Extracts: Evaluation of Phenolic Acids and Flavonoids by Liquid Chromatography – Electrospray Ionization – Tandem Mass Spectrometry (LC–ESI–MS) and the Antioxidant Activity. Analytical Letters, 53(9), 1366-1377. doi:10.1080/00032719.2019.1706546Ziadi, M., Bouzaiene, T., Lakhal, S., Zaafouri, K., Massoudi, S., Dousset, X., & Hamdi, M. (2019). Screening of lactic starter from Tunisian fermented vegetables and application for the improvement of caper (Capparis spinosa) fermentation through an experimental factorial design. Annals of Microbiology, 69(13), 1373-1385. doi:10.1007/s13213-019-01519-xBenachour, H., Ramdani, M., Lograda, T., Chalard, P., & Figueredo, G. (2019). Chemical composition and antibacterial activities of Capparis spinosa essential oils from Algeria. Biodiversitas Journal of Biological Diversity, 21(1). doi:10.13057/biodiv/d210121Bagherifard, A., Hamidoghli, Y., Biglouei, M. H., & Ghaedi, M. (2020). Effects of drought stress and superabsorbent polymer on morpho-physiological and biochemical traits of Caper (Capparis spinosa L.). Australian Journal of Crop Science, (14(01) 2020), 13-20. doi:10.21475/ajcs.20.14.01.p1418Orphanos, P. I. (1983). Germination of caper (Capparis spinosaL.) seeds. Journal of Horticultural Science, 58(2), 267-270. doi:10.1080/00221589.1983.11515119Sozzi, G. O., & Chiesa, A. (1995). Improvement of caper (Capparis spinosa L.) seed germination by breaking seed coat-induced dormancy. Scientia Horticulturae, 62(4), 255-261. doi:10.1016/0304-4238(95)00779-s. Z. Ö., . Z. Y., & . A. Ö. Ü. (2004). Effects of H2SO4, KNO3 and GA3 Treatments on Germination of Caper (Capparis ovata Desf.) Seeds. Pakistan Journal of Biological Sciences, 7(6), 879-882. doi:10.3923/pjbs.2004.879.882Pascual, B., San Bautista, A., Imbernón, A., López-Galarza, S., Alagarda, J., & Maroto, J. V. (2004). Seed treatments for improved germination of caper (Capparis spinosa). Seed Science and Technology, 32(2), 637-642. doi:10.15258/sst.2004.32.2.33Pascual, B., San Bautista, A., Pascual Seva, N., García Molina, R., López-Galarza, S., & Maroto, J. V. (2009). Effects of soaking period and gibberellic acid addition on caper seed germination. Seed Science and Technology, 37(1), 33-41. doi:10.15258/sst.2009.37.1.05Pascual-Seva, N., San Bautista, A., López-Galarza, S., Maroto, J. V., & Pascual, B. (2011). EFFECT OF ACCELERATED AGEING ON GERMINATION IN CAPER (CAPPARIS SPINOSA L.) SEEDS. Acta Horticulturae, (898), 69-74. doi:10.17660/actahortic.2011.898.7Juan, M., Pascual-Seva, N., Iranzo, D., & Pascual, B. (2020). Improvement of seed germination of caper (Capparis spinosa L.) through magnetic fields. Acta Horticulturae, (1273), 433-440. doi:10.17660/actahortic.2020.1273.56Baskin, J. M., & Baskin, C. C. (2004). A classification system for seed dormancy. Seed Science Research, 14(1), 1-16. doi:10.1079/ssr2003150Baskin, J. M., Baskin, C. C., & Li, X. (2000). Taxonomy, anatomy and evolution of physical dormancy in seeds. Plant Species Biology, 15(2), 139-152. doi:10.1046/j.1442-1984.2000.00034.xOrozco-Segovia, A., Marquez-Guzman, J., Sanchez-Coronado, M. E., Gamboa de Buen, A., Baskin, J. M., & Baskin, C. C. (2006). Seed Anatomy and Water Uptake in Relation to Seed Dormancy in Opuntia tomentosa (Cactaceae, Opuntioideae). Annals of Botany, 99(4), 581-592. doi:10.1093/aob/mcm001Bahrani, M. J., Ramazani Gask, M., Shekafandeh, A., & Taghvaei, M. (2008). Seed germination of wild caper (Capparis spinosa L., var. parviflora) as affected by dormancy breaking treatments and salinity levels. Seed Science and Technology, 36(3), 776-780. doi:10.15258/sst.2008.36.3.27Torres, M., & Frutos, G. (1990). Logistic function analysis of germination behaviour of aged fennel seeds. Environmental and Experimental Botany, 30(3), 383-390. doi:10.1016/0098-8472(90)90051-5Pascual, B., San Bautista, A., López-Galarza, S., Alagarda, J., & Maroto, J. V. (2006). Germination behaviour after storage of caper seeds. Seed Science and Technology, 34(1), 151-159. doi:10.15258/sst.2006.34.1.16MA, F. (2004). Cracks in the Palisade Cuticle of Soybean Seed Coats Correlate with their Permeability to Water. Annals of Botany, 94(2), 213-228. doi:10.1093/aob/mch13

Chufa

Pascual España, B.; Pascual-Seva, N. (2017). Chufa. En Cultivos hortícolas al aire libre. Cajamar Caja Rural. 85-110. http://hdl.handle.net/10251/114762S8511

Effect of Deficit Irrigation on the Productive Response of Drip-irrigated Onion (Allium cepa L.) in Mediterranean Conditions

[EN] Water is an essential resource for food production, and agriculture consumes close to 69% of total freshwater use. Water shortage is becoming critical in arid and semiarid areas worldwide; therefore, it is vital to use water efficiently. The objective of this research was to evaluate the response of onion growth, plant water status, bulb yield, irrigation water use efficiency and bulb quality using three continued deficit strategies, applying 100, 75, and 50% of the irrigation water requirements during three seasons. The yield response factor was 0.71, indicating that in the analysed conditions the crop was tolerant to a water deficit. Compared to full irrigation, deficit irrigation with 75% of the irrigation water requirements resulted in a low yield and profit reduction for the growers (10.3% and 10.9%, respectively), but also important water savings (26.6%), improving both the irrigation water use efficiency and water use efficiency. However, onion exposure to severe water deficits at 50% of the irrigation water requirements drastically reduced plant growth and bulb yield and growers' profits, although it did increase their soluble solid content. Irrigating at 75% of the irrigation water requirements could be an actionable strategy for onion production under water-limited conditions.Abdelkhalik, A.; Pascual-Seva, N.; Nájera, I.; Domene, MA.; Baixauli Soria, C.; Pascual España, B. (2019). Effect of Deficit Irrigation on the Productive Response of Drip-irrigated Onion (Allium cepa L.) in Mediterranean Conditions. Horticulture Journal. 88(4):488-498. https://doi.org/10.2503/hortj.UTD-081S48849888

Response of drip-irrigated chufa (Cyperus esculentus L. var. sativus Boeck.) to different planting configurations: Yield and irrigation water-use efficiency

[EN] A two-year study was conducted to analyze the yield and irrigation water-use efficiency of chufa crop in response to planting configuration and drip irrigation scheduling as a function of the volumetric soil water content. The planting configurations were: beds with three plant rows and three driplines (B3), beds with three plant rows and two driplines (B2), beds with two plant rows and two driplines (b), and ridges (R). The yield was affected by the planting configuration; greater yields were obtained in beds (on average 2.36 kg m−2) than in R (2.14 kg m−2). Considerably less irrigation water was applied in R and in B2 than in beds B3 and b. The irrigation water-use efficiency was affected by the planting configuration in the same line that the irrigation water was applied, with greater values being obtained in B2 (7.58 kg m−3) than in the R (6.63 kg m−3), which in turn was higher than B3 (5.92 kg m−3) and b (5.69 kg m−3). These values of the irrigation water-use efficiency were considerably higher than those obtained in previous experiments (based on the volumetric soil water content in the ridges). Neither the yield nor the average tuber weight were affected by the position of the different planting rows in the bed.This study was funded by the Regulatory Council of Denomination of Origin Chufa of Valencia of Spain.Pascual Seva, N.; San Bautista Primo, A.; López Galarza, SV.; Maroto Borrego, JV.; Pascual España, B. (2016). Response of drip-irrigated chufa (Cyperus esculentus L. var. sativus Boeck.) to different planting configurations: Yield and irrigation water-use efficiency. Agricultural Water Management. 170:140-147. doi:10.1016/j.agwat.2016.01.02114014717

Growth and nutrient absorption in chufa (Cyperus esculentus L. var. sativus Boeck.) in soilless culture

[EN] The efficiency of fertilisation in agriculture is often low, and if one knows the nutrient uptake rate, efficiency can be improved by synchronizing nutrient supply with nutrient demand. Growth and the time-course of nutrient accumulation and its partitioning between the different organs of chufa (Cyperus esculentus L. var. sativus Boeck.), an under-exploited cultivated plant, were examined. The study was conducted in soilless, open-field conditions, at a planting density equivalent to 55,500 plants ha-1 in three consecutive seasons. Plants were sampled, fractionated into leaves, roots, and tubers, then dried and weighed. Their macronutrient contents were analysed fortnightly. On average, the yield was 5.0 kg fresh weight tuber m-2 . Growth of the whole plant until 90 d after planting obeys an exponential function of time; the relative growth rate (RGR) for this period was determined. The highest N and K concentrations were recorded in leaves, and the highest P, Ca and Mg concentrations were found in roots. The highest accumulations of N and P were found in tubers, and of K and Ca in leaves. Nitrogen had the highest nutrient accumulation (58.3 g m-2 ) as well as the highest specific uptake rate.This study was funded by the Consejo de Denominacion de Origen Chufa de Valencia, Spain. The authors thank the agricultural engineers, Juan Andres and Ramon Ballester, for assisting with the previous experiments, and Debra Westall for revising the manuscript.Pascual-Seva, N.; Pascual España, B.; San Bautista Primo, A.; López Galarza, SV.; Maroto Borrego, JV. (2009). Growth and nutrient absorption in chufa (Cyperus esculentus L. var. sativus Boeck.) in soilless culture. The Journal of Horticultural Science and Biotechnology. 84(4):393-398. doi:10.1080/14620316.2009.11512538S393398844Alegría, A. and Farré, R. (2003). Horchata and health: nutritional and dietetic aspects. In:Conference on Chufa and Horchata, Tradition and Health.(In Spanish). Fundación Valenciana de Estudios Avanzados, Valencia, Spain. 55–70.Andrés, J. (2006).Study of Nutrition, Principal Macronutrients Accumulation Rates, and Yield of Chufa(Cyperus esculentus L.var.sativusBoeck.)Growing in Perlite.(In Spanish). M.Sc. Thesis. Universidad Politécnica de Valencia, Valencia, Spain. 89 pp.A.O.A.C. (1990).Official Methods of Analysis.5th Edition. Association of Official Analytical Chemists Inc., Arlington, VA, USA. 40–42.Ballester, R. (2006).Influence of the Irrigation Frequency and Management in Nutrition, Growth, and Yield of Chufa(Cyperus esculentus L.var.sativusBoeck.). (In Spanish). M.Sc. Thesis. Universidad Politécnica de Valencia, Valencia, Spain. 76 pp.Bixquert, M. (2003). Horchata and health: healthy properties and prevention of digestive diseases. In:Conference on Chufa and Horchata, Tradition and Health.(In Spanish). Fundación Valenciana de Estudios Avanzados, Valencia, Spain. 71–85.Gardner, F. P., Pearce, R. B. and Mitchell, R. L. (1985).Physiology of Crop Plants.Iowa State University Press, Ames, IA, USA. 187–208.Maynard, D. N. and Hochmuth, G. J. (1997).Knott’s Handbook forVegetable Growers.John Wiley & Sons Inc., NY, USA. 45–218.Pascual, B., Maroto, J. V., López-Galarza, S., Alagarda, J. and Castell-Zeising, V. (1997).Studies Carried out in Chufa Cultivation.(In Spanish). Generalitat Valenciana, Conselleria de Agricultura, Pesca y Alimentación, Valencia, Spain. 95 pp.Sas (1993).SAS/STAT®User’s Guide.Version 6. 2nd Edition. SAS Institute Inc., Cary, NC, USA. 1022 pp.Ter Borg, S. J. and Schippers, P. (1992). Distribution of varieties ofCyperus esculentusL. (yellow nutsedge) and their possible migration in Europe.9thInternational Symposium on the Biology of Weeds. Annals of the Symposium.417–425

Response of nutsedge (Cyperus esculentus L. var sativus Boeck.) tuber production to drip irrigation based on volumetric soil water content

The final publication is available at Springer via http://dx.doi.org/10.1007/s00271-014-0446-0Cultivated nutsedge is a common crop in Valencia (Spain). The aim of this research, which was conducted over two consecutive years, was to compare the productive response of the nutsedge crop with drip irrigation and traditional furrow irrigation, calculating the yield and the irrigation water use efficiency (IWUE). The volumetric soil water content was monitored with capacitance probes. Four irrigation strategies were considered: three in drip irrigation [D70, D80 and D90 with refill points at 70, 80 and 90 % of the field capacity, respectively] and one in furrow irrigation (refill point at 60 % field capacity); in the second year, the irrigation management was automated. On average, strategy D90 produced the highest yield and D70 the lowest, while the highest IWUE was obtained with D80 and the lowest with furrow irrigation. Considering the automation of irrigation management, strategy D90 led to the highest yield and to the highest IWUE.This study was funded by the Regulatory Council of Denomination of Origin Chufa of Valencia of Spain.Pascual Seva, N.; San Bautista Primo, A.; López Galarza, SV.; Maroto Borrego, JV.; Pascual España, B. (2015). Response of nutsedge (Cyperus esculentus L. var sativus Boeck.) tuber production to drip irrigation based on volumetric soil water content. Irrigation Science. 33(1):31-42. doi:10.1007/s00271-014-0446-0S3142331Abrisqueta I, Vera J, Tapia LM, Abrisqueta JM, Ruiz-Sánchez MC (2012) Soil water content criteria for peach trees water stress detection during the postharvest period. Agric Water Manag 104:62–67Allen RG, Pereira LS, Raes D, Smith M (1998) Crop evapotranspiration. Guidelines for computing crop water requirements. FAO, RomeAyers RS, Westcot DW (1994) Water quality for agriculture. FAO Irrigation and Drainage, 29 Rev1. FAO, Roma, ItalyBell JP, Dean TJ, Hodnett MG (1987) Soil moisture measurements by an improved capacitance technique, part II. Field techniques, evaluation and calibration. J Hydrol 93:79–90Bernstein L, Francois LE (1973) Comparisons of drip, furrow, and sprinkler irrigation. Soil Sci 115:73–86Bos MG (1980) Irrigation efficiencies at crop production level. ICID Bull 29:18–25Bresler E (1977) Trickle-drip irrigation: principles and application to soil-water management. Adv Agron 29:343–393Cabello MJ, Castellanos MT, Romojaro F, Martínez-Madrid C, Ribas F (2009) Yield and quality melon grown under different irrigation and nitrogen rates. Agric Water Manag 96:874–886Clemmens AJ, Molden DJ (2007) Water uses and productivity of irrigation systems. Irrig Sci 25:247–261Condori B, Mamani P, Botello R, Patiño F, Devaux A, Ledent JF (2008) Agrophysiological characterisation and parameterisation of Andean tubers: potato (Solanum sp.), oca (Oxalis tuberosa), isaño (Tropaeolum tuberosum) and papalisa (Ullucus tuberosus). Eur J Agron 28:526–540Corominas J (2009) Agua y energía en el riego, en la época de la sostenibilidad. Ingeniería del Agua 17:219–233Farré I, Faci JM (2009) Deficit irrigation in maize for reducing agricultural water use in a Mediterranean environment. Agric Water Manag 96:383–394Howell TA (2001) Enhancing water use efficiency in irrigated agriculture. Agron J 93:281–289Howell TA, Cuenca RH, Solomon KH (1990) Crop yield response. In: GJ Hoffman, TA Howell, KH Solomon (eds), Management of farm irrigation systems. ASAE, St Joseph, MI, USA, pp:93-122Howell TA, Yazar A, Schneider AD, Dusek DA, Copeland KS (1995) Yield and water use efficiency of corn in response to LEPA irrigation. Trans ASAE 36:1737–1747Hussein-Mounzer O, Mendoza-Hernández JR, Abrisqueta-Villena I, Tapia-Vargas L, Abrisqueta-García JM, Vera-Muñoz J, Ruiz-Sánchez MC (2008) Soil water content measured by FDR probes and thresholds for drip irrigation management in peach trees. Agric Téc Méx 34:313–322Ko J, Piccinni G (2009) Corn yield responses under crop evapotranspiration-based irrigation management. Agric Water Manag 96:799–808Maynard DN, Hochmuth GJ (1997) Knott’s handbook for vegetable growers. Wiley, NYMINETUR [Spanish Ministry of Industry, Energy and Tourism] (2014) Peajes y tarifas. Energía eléctrica. Ministerio de Industria, Energía y Turismo. http://www.minetur.gob.es/energia/electricidad/Tarifas/Paginas/index.aspx . Accessed 3 August 2014Molden D, Murray-Rust H, Sakthivadivel R, Makin I (2003) A water-productivity framework for understanding and action. In: Kjine JW, Barker R, Molden D (eds) Water productivity in agriculture. International Water Management Institute, Colombo, pp 1–18MOPT [Spanish Ministry of Public Works and Transport] (1992) Guía para la elaboración de estudios del medio físico. Ministerio de Obras Públicas y Transporte, MadridMushagalusa GN, Ledent JF, Draye X (2008) Shoot and root competition in potato/maize intercropping: effects on growth and yield. Environ Exper Bot 64:180–188Pascual B, Maroto JV, López-Galarza S, Alagarda J, Castell-Zeising V (1997) El cultivo de la chufa (Cyperus esculentus L. var. sativus Boeck.). Estudios realizados. Generalitat Valenciana, Conselleria de Agricultura, Pesca y Alimentación, Valencia, SpainPascual B, Maroto JV, López-Galarza S, San Bautista A, Alagarda J (1999) Chufa (Cyperus esculentus L. var. sativus Boeck): an unconventional crop. Studies related to applications and cultivation. Econ Bot 54:439–448Pascual-Seva N, San Bautista A, López-Galarza S, Alagarda J, Maroto JV, Pascual B (2008) Respuesta productiva de la chufa (Cyperus esculentus L. var. sativus Boeck.) en riego localizado. Actas de Horticultura 50:170–175Pascual-Seva N, Pascual B, San Bautista A, López-Galarza S, Maroto JV (2009) Growth and nutrient absorption in chufa (Cyperus esculentus L. var. sativus Boeck.) in soilless culture. J Hort Sci Biot 84:393–398Pascual-Seva N, San Bautista A, López-Galarza S, Maroto JV, Pascual B (2013a) Furrow-irrigated chufa crops in Valencia (Spain). I: productive response to two irrigation strategies. Span J Agric Res 11:258–267Pascual-Seva N, San Bautista A, López-Galarza S, Maroto JV, Pascual B (2013b) Furrow-irrigated chufa crops in Valencia (Spain). II: performance analysis and optimization. Span J Agric Res 11:268–278Quemada M, Gabriel JL, Lizaso J (2010) Calibration of capacitance probes: laboratory versus field procedures. In: Paltineanu IC, Vera J (eds), Transactions. The third international symposium on soil water measurement using capacitance, impedance and TDT. CEBAS-CSIC, PALTIN International Inc, Murcia, Spain, pp: 2.2:1-14Shahnazari A, Liu F, Andersen MN, Jacobsen SE, Jensen CR (2007) Effects of partial root-zone drying on yield, tuber size and water use efficiency in potato under field conditions. Field Crops Res 100:117–124Shock CC, Feibert EBG, Saunders LD (1998) Potato yield and quality response to deficit irrigation. HortScience 33:655–659Soil Survey Staff (2010) Keys to soil taxonomy, 11th edn. USDA-Natural Resources Conservation Service, WashingtonSolomon KH, El-Gindy AM, Ibatullin SR (2007) Planing and system selection. In: Hoffman GJ, Evans RG, Jensen ME, Martin DL, Elliot RL (eds) Design and operation of farm irrigation systems. ASABE, St Joseph, MI, USA, pp 57–75Statistical Graphics Corporation (2005) Statgraphics Plus for Windows 5.1. Statistical Graphics, Rockville, Maryland, USATolk JA, Howell T (2003) Water use efficiencies of grain sorghum grown in three USA southern Great Plains soils. Agric Water Manag 59:97–111Van der Veeken AJH, Loomen WJM (2009) How planting density affects number and yield of potato minitubers in a commercial glasshouse production system. Potato Res 52:105–119Veihmeyer FJ, Hendrickson AH (1931) The moisture equivalent as a measure of the field capacity of soils. Soil Sci 32:181–193Vera J, Mounzer O, Ruiz-Sánchez MC, Abrisqueta I, Tapia LM, Abrisqueta JM (2009) Soil water balance trial involving capacitance and neutron probe measurements. Agric Water Manag 96:905–911Viets FG (1962) Fertilizers and the efficient use of wáter. Adv Agron 14:223–264Yuan BZ, Nishiyama S, Kang Y (2003) Effects of different irrigation regimes on the growth and yield of drip-irrigated potato. Agric Water Manag 63:153–16

Influence of different drip irrigation strategies on irrigation water use efficiency on chufa (Cyperus esculentus L. var. sativus Boeck.) crop

[EN] Chufa is a typical crop in Valencia, Spain, where it is cultivated in ridges with furrow irrigation. It uses large volumes of water, and thus, different studies have been undertaken to maximize irrigation water use efficiency to obtain important water savings. Particularly, different values for turning water on, considering the basis of volumetric soil water content were analysed in drip irrigation. It was reported that starting each irrigation event when the volumetric soil water content dropped to 90% of the field capacity resulted in the best yield, and the best irrigation water use efficiency was obtained when it dropped to 80% of the field capacity. However, these results may be improved by defining the optimum criteria for turning water off, which is the aim of the present research. This investigation, conducted in 2015, 2016 and 2017, analises the productive response of the drip irrigated chufa crop, determining the yield and the irrigation water use efficiency. The volumetric soil water content was monitored using multi-depth capacitance probes, with sensors at 0.10, 0.20 and 0.30 m below the top of the ridge. Each irrigation event started when the volumetric soil water content at 0.10 m dropped to 85% of field capacity. Three irrigation strategies were considered. T1: each event resulting in water being turned off when the sum of the volumetric soil water content values that were measured at 0.10, 0.20 and 0.30 m reached the corresponding field capacity value; T2: turning water off in each event when the volumetric soil water content values that were measured at 0.20 m reached the corresponding field capacity value; and T3: each irrigation event applying 8.5 mm in 2015 and 2016, as well as 9.8 mm in 2017. Overall, the T2 strategy resulted in the largest yield, and T3 resulted in the highest irrigation water use efficiency in 2015 and 2016. The average tuber weight and dry matter content did not differ between the irrigation strategies.This work was supported by the Generalitat Valenciana [GV/2017/037].Pascual-Seva, N.; San Bautista Primo, A.; López Galarza, SV.; Maroto Borrego, JV.; Pascual España, B. (2018). Influence of different drip irrigation strategies on irrigation water use efficiency on chufa (Cyperus esculentus L. var. sativus Boeck.) crop. Agricultural Water Management. 208:406-413. https://doi.org/10.1016/j.agwat.2018.07.003S40641320

Effects of soaking period and gibberellic acid addition on caper seed germination

[EN] In order to improve caper seed germination, this two-year study (2005-2006) was designed to determine the effects of seed soaking treatments and soaking times. individually or in combination with the addition of gibberellic acid to the germination substrate. Besides testing the control seeds, 7 soaking periods were assayed. soaking seeds in tap water at room temperature for 24 h, 15, 30, 45, 60, 75 and 90 days. Germination tests were performed in closed Petri dishes in a growth chamber. Germination data were fitted to the logistic function and calculations were made for the maximum germination percentage, the time to reach 50% of final germination and the mean relative cumulative rate. A soaking period of 30 days or longer enhanced seed germination: final germination values ranged from 95 to 99%, reducing the time to reach 50% of final germination and consequently the duration of germination tests. Addition of gibberellic acid to the substrate after soaking improved germination only for control seeds and those soaked for 24 It or 15 days. Seed soaking for 30 or 45 days, followed or not by the addition of a gibberellic acid Solution to the substrate. is an efficient method to enhance caper seed germination.Pascual España, B.; San Bautista Primo, A.; Pascual-Seva, N.; Garcia Molina, R.; López Galarza, SV.; Maroto Borrego, JV. (2009). Effects of soaking period and gibberellic acid addition on caper seed germination. Seed Science and Technology. 37(1):33-41. doi:10.15258/sst.2009.37.1.05S334137

Influence of substrate on strawberry plug plant production

[EN] The plug plant technique for the commercial propagation of strawberries is increasing in importance. Several factors, including the properties of the substrate, can affect plug plant quality. Tests on nine substrates containing different proportions of perlite [from 0 ¿ 75%, (v/v)], and dark and light peat [both from 0 ¿ 80% (v/v)], were performed using a simplex-lattice design in order to establish a model for strawberry plug plant production based not only on the single component composition of the substrate, but also on the influences of the chemical and physical properties of the substrate on plug plant quality. Notable differences in physical and chemical properties were found among the nine different substrates tested, as a consequence of the broad range of their component compositions. Substrate mixes containing medium-to-high proportions [from 60 ¿ 70% (v/v)] of light peat and low proportions of dark peat and perlite are recommended, as these resulted in a low nutrient content, a high organic matter content, a low pH, and a low ¿coarseness¿ index, which led to high-grade plug plants with greater root and crown dry weights.Funding was provided by the Spanish Ministry for Science and Technology-FEDER through Research Project No. AGL2004-04365/AGR. The authors are grateful to Dr. J.L. Guardiola and Dr. Manual Abad for comments on this manuscript. The authors are also grateful to Ms. Debra Westall for revising the grammar of the manuscript.López Galarza, SV.; San Bautista Primo, A.; Pascual España, B.; Maroto Borrego, JV. (2010). Influence of substrate on strawberry plug plant production. Journal of Horticultural Science. 85(5):415-420. doi:10.1080/14620316.2010.11512690S41542085

COVIDSensing: Social Sensing strategy for the management of the COVID-19 crisis

[EN] The management of the COVID-19 pandemic has been shown to be critical for reducing its dramatic effects. Social sensing can analyse user-contributed data posted daily in social-media services, where participants are seen as Social Sensors. Individually, social sensors may provide noisy information. However, collectively, such opinion holders constitute a large critical mass dispersed everywhere and with an immediate capacity for information transfer. The main goal of this article is to present a novel methodological tool based on social sensing, called COVIDSensing. In particular, this application serves to provide actionable information in real time for the management of the socio-economic and health crisis caused by COVID-19. This tool dynamically identifies socio-economic problems of general interest through the analysis of people¿s opinions on social networks. Moreover, it tracks and predicts the evolution of the COVID-19 pandemic based on epidemiological figures together with the social perceptions towards the disease. This article presents the case study of Spain to illustrate the tool.This work is derived from R&D project RTI2018-096384-B-I00, as well as the Ramon y Cajal Grant RYC2018-025580-I, funded by MCIN/AEI/10.13039/501100011033 and ERDF A way of making Europe, by the Spanish Agencia Estatal de Investigación (grant number PID2020- 112827GB-I00/ AEI/10.13039/501100011033), and by the Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital, Proyectos AICO/2020, Spain, under Grant AICO/2020/302.Sepúlveda, A.; Periñán-Pascual, C.; Muñoz, A.; Martínez-España, R.; Hernández-Orallo, E.; Cecilia-Canales, JM. (2021). COVIDSensing: Social Sensing strategy for the management of the COVID-19 crisis. Electronics. 10(24):1-17. https://doi.org/10.3390/electronics10243157S117102