Received for publication: 10 April, 2015. Accepted for publication: 30 June, 2015. Doi: 10.15446/agron.colomb.v33n2.52000 1 Faculty of Basic and Applied Sciences, Agrobiology Research Group, Universidad Militar Nueva Granada, Cajicá (Colombia). carlmgrijalba@gmail.com, agrobiologia@unimilitar.edu.co Agronomía Colombiana 33(2), 147-154, 2015 Strawberry yields with high-tunnel and open-field cultivations and the relationship with vegetative and reproductive plant characteristics Rendimiento del cultivo de fresa bajo macrotúnel y a campo abierto y su relación con aspectos vegetativos y reproductivos de la planta Carlos Mario Grijalba1, María Mercedes Pérez-Trujillo1, Diana Ruiz1, and Ana María Ferrucho1 ABSTRACT RESUMEN In Colombia, high-tunnel systems may be a viable alternative for increasing the yields of strawberry crops due to their ability to prevent fruit losses and plant damage caused during periods of high precipitation. This study aimed to compare the yield and its relationship with vegetative and reproductive components of Albion and Monterey strawberry cultivars, established in open-field and high-tunnel systems in Cajica (Colombia), at 2,562 m a.s.l. and 4°56´N, 74°00´W. A combined analysis of the environments was carried out. A random complete block design was used in each environment with six replications for each cultivar. This study evaluated the relationship between the leaf area, the number of crowns, the number of leaf lets, the number of f lowers, the number of inf lorescences, the number of f lowers per inf lorescence, the number of fruits, the incidence of foliar damage, the yield per plant and the fruit size. There were positive correlations between the vegetative variables and the reproductive variables, which explained why ‘Monterey’, a cultivar with more vigor, presented a higher yield that ‘Albion’. The growth conditions in the high-tunnel system promoted rapid vegetative growth in the ‘Monterey’ plants, with an in- crease in yield and a decrease in losses. The ‘Albion’ cultivar plants in the high-tunnel system presented a decrease in fruit losses; however, these plants did not present differences in the yield, as compared to the plants established in the open-filed system. Despite the benefits of a decrease in fruit losses due to rot seen in the high-tunnel system, this system had an increase in powdery mildew and calcium deficiency. En Colombia, los macrotúneles pueden ser una alternativa viable para aumentar los rendimientos en el cultivo de fresa debido a su capacidad para prevenir pérdidas de fruta y daños en las plantas ocasionados en las épocas de altas precipita- ciones. El objetivo del estudio fue comparar el rendimiento y su relación con componentes vegetativos y reproductivos, de los cultivares de fresa Albion y Monterey establecidos en condiciones de campo abierto y bajo macrotúnel, en Cajicá (Co- lombia), 2.562 msnm y 4°56’N, 74°00’O. Se realizó un análisis combinado de los ambientes. En cada ambiente se trabajó un diseño de bloques completos al azar con seis repeticiones para cada cultivar. Se evaluaron las relaciones entre el área foliar, el número de coronas, de foliolos, de f lores, de inf lorescencias, de f lores por inf lorescencia, de frutos, la incidencia de daños foliares, el rendimiento por planta y el tamaño del fruto. Se presentaron correlaciones positivas entre las variables vegeta- tivas con las reproductivas, lo que explica porque ‘Monterey’, un cultivar con mayor vigor, presentó un mayor rendimiento que las plantas del cultivar ‘Albion’. Las condiciones de creci- miento en el macrotúnel promovieron un rápido crecimiento vegetativo en las plantas de ‘Monterey’ con un aumento en los rendimientos y disminución en las pérdidas. Las plantas del cul- tivar ‘Albion’ bajo macrotúnel presentaron una disminución en las pérdidas de fruta, sin embargo, no presentaron diferencias de rendimiento en comparación a las establecidas en campo abierto. A pesar de los beneficios que trae el macrotúnel en la disminución de pérdidas de la fruta a causa de pudriciones, se presentó un aumento en la incidencia de mildeo polvoso y la deficiencia de calcio. Key words: Fragaria x ananassa, ‘Monterey’, ‘Albion’, high tropics, crop protection, plant health. Palabras clave: Fragaria x ananassa, ‘Monterey’, ‘Albion’, trópico alto, protección de cultivos, fitosanidad. (Halvorsen et al., 2006). In Colombia, the cultivated area for strawberries drastically increased between 2000 and 2009, from 629 ha to 1,306 ha, and, starting this year, the culti- vated area has remained constant, with yields between 30 and 40 t ha-1 yr-1 (Agronet, 2014). In Colombia, good yields are possible thanks to year-round production, with harvest Introduction The strawberry (Fragaria x ananassa) is considered the most economically important berry worldwide (Hummer and Hancock, 2009). Its fruit is highly appreciated due to its organoleptic properties and phytochemical content http://dx.doi.org/10.15446/agron.colomb.v33n2.52000 mailto:carlmgrijalba@gmail.com mailto:agrobiologia@unimilitar.edu.co 148 Agron. Colomb. 33(2) 2015 peaks that occur approximately every 3 or 4 months, as has been reported for other high tropical zones of South America, such as Ecuador (Hancock, 1999; Kirschbaum and Hancock, 2000). One of the methods for increasing yields involves the use of plastic covers, which are designed to modify the environmental conditions in order to prolong the harvest period, increase early crops, increase yields, improve qual- ity, reduce the mechanical damage caused by hail and/or strong rain, and reduce the incidence of phytopathogenic fungi, among others (Wittwer and Castilla, 1995; Jiang et al., 2003). One such method is the high-tunnel system, which, when compared to greenhouses, is low-cost and provides a viable alternative due to its favorable technical/ economic optimization ratio (Ferrato et al., 2003; Lamont, 2009). High-tunnels are semi-permanent structures and, unlike some greenhouses, are not automated and do not use electrical systems for permanent heating or cooling, but instead use passive ventilation (Wells, 1996; Carey et al., 2009; Lamont, 2009). The open-field system is the predominant strawberry pro- duction method in Colombia (Rubio et al., 2014); however, due to the high precipitation in the producing regions, high-tunnels could mitigate some phytosanitary problems by reducing the free water on the plants and fruits (Jensen and Malter, 1995; Lamont, 2009). The most common dis- ease in this fruit is caused by the phytopathogen Botrytis cinerea and causes a significant decrease in yield (Ceredi et al., 2009). High-tunnels have the ability to decrease losses because they generate an environment that is less conducive for this phytopathogen, as reported by Xiao et al. (2001). This study aimed to evaluate the yield and its relationship with the vegetative and reproductive components of Albion and Monterey strawberry cultivars established under high- tunnel and open-field systems. Materials and methods This study was conducted in the municipality of Cajica (Cundinamarca, Colombia), in the experimental fields of the Universidad Militar Nueva Granada, located at 4°56’N, 74°00’W and 2,562 m a.s.l. The vegetative material was composed of “frigo” strawberry plants of the Albion and Monterey cultivars, which were planted in September of 2012 in 6 beds (0.70 m wide, 0.40 m high, 13.5 m long), that were covered with black poly- ethylene mulch. Each bed had two rows of staggered plants with a distance between the rows of 0.3 m and between the plants of 0.3 m. In each crop environment (high-tunnel and open-field), closed fertigation circuit was used with two drip lines per bed and daily irrigation at a volume of 200 mL/plant. The No. 2 nutritive solution of Hoagland and Arnon (1950) was used for the fertigation, as cited by Cadahía (2005), which was adjusted in accordance with the soil analysis. This study used two environments: open-field and high- tunnel; each one had an area of 200 m2. Three high-tunnels were installed (2.7 m high, 4.0 m wide, 18.0 m long). Tak- ing into account the low seasonal temperature f luctuation seen in high tropical zones coupled with a big variation in temperature throughout the day, the design of the high- tunnels used in this study employed passive ventilation to avoid temperatures over 28°C, which have been reported to negatively affect f lowering and yields in this crop (Han- cock, 1999; Chen, 2013). A randomized complete block design was used in each crop environment with six replications for the two treat- ments, which corresponded to the Albion cultivar and the Monterey cultivar. Each block had 30 plants, from which 10 uniform plants in full competition were selected for the respective response variable monitoring. The monitoring of the air temperature, relative humidity, and precipitation was carried out in each environment with meteorological stations, registering the information hourly. The leaf area was determined per plant with a nondestruc- tive method using a previously adjusted model that esti- mated the leaf area from the length of the leaf lets with the equation Y = 0.8316X1.0784 (R2=0.956), where Y is the area of the leaf let (cm2) and X is the length of the leaf let (cm). The variables of leaf area, number of crowns (stems), number of leaf lets, number of f lowers, number of inf lorescences and number of f lowers per inf lorescence, were evaluated per plant during 10 samplings that were distributed over 202 das (days after sowing). All of the leaves of each plant were inspected to determine the number of leaves affected by biotic or abiotic factors. Afterwards, using this information, the damage incidence was determined from the percentage of affected leaves in relation to the total number of leaves per plant. The yield was evaluated per plant during 54 weeks of har- vesting. The fruit weight and diameter were evaluated with all of the harvested fruits per plant until 202 das. In order to evaluate the relationship between the vegetative and reproductive components of the plants (including the 149Grijalba, Pérez-Trujillo, Ruiz, and Ferrucho: Strawberry yields with high-tunnel and open-field cultivations and the relationship with vegetative and reproductive... yield), the data of the different variables were accumulated for each plant for 202 das, and Spearman correlations were applied with SAS® v.9.1.3 (SAS Institute, Cary, NC). With the same data, a principal components analysis was carried out with Statgraphics Centurion® XVI v.16.2.04 (StatPoint Technologies, Warrenton, VA). Furthermore, the yield results were subjected to a combined analysis of variance with SAS and the multiple comparisons were evaluated using the LSMEANS and DIFF commands of the PROC GLM procedure. Results and discussion The majority of the vegetative variables (leaf area, number of crowns, number of leaf lets), were correlated with the reproductive variables (number of f lowers, number of inf lorescences, number of f lowers per inf lorescence), and with the yield (production and number of fruits), as can be seen in Figs. 1 and 2. The entire variable block, from the crowns to the inf lorescences, presented highly significant correlations and, at the same time, the yield and number of fruits were highly dependent on the number of f lowers and the number of inf lorescences. The damage incidence in the strawberry leaves negatively affected the number of inf lorescences and, therefore, the yield. The variable of f lowers per inf lorescence presented a positive relationship with some of the vegetative variables and yield; however, their correlation coefficients were low. Using the principal components analysis, the results were summarized in the correlations and the relationship with new variables was added. The first principal component 0.81943 0.73256 0.58126 0.51206 0.17747 -0.11097 0.18994 0.17545 <0.0001 <0.0001 <0.0001 <0.0001 0.0545 0.2316 0.0394 0.0574 0.83341 0.64084 0.59192 0.18007 -0.20396 0.24453 0.2703 <0.0001 <0.0001 <0.0001 0.051 0.0267 0.0076 0.0031 0.56355 0.4837 0.20622 -0.08977 0.23329 0.23777 <0.0001 <0.0001 0.0251 0.3337 0.011 0.0095 0.91509 0.27339 -0.11701 0.55631 0.55381 <0.0001 0.0027 0.207 <0.0001 <0.0001 -0.07788 -0.18426 0.48262 0.48579 0.4019 0.0458 <0.0001 <0.0001 0.06397 0.23184 0.23717 0.4913 0.0115 0.0097 -0.18512 -0.1896 0.0448 0.0397 0.89994 <0.0001 Crowns Leaflets Leaf area Flowers Inflorescences Leaflet damage Production Fruits Production Fruits Leaflet damage Inflorescences Crowns Leaflets Leaf area Flowers /inflorescence Flowers Flowers /inflorescence 1 1 1 1 1 1 1 1 1 FIGURE 1. Correlations between the variables evaluated in the Albion cultivar until 202 d after sowing. The numbers in the upper row of each square indicate the coefficient of determination (r), and the numbers in the lower row indicate the significance according to the Spearman method. The white color indicates that the correlation was not significant and the gray scale, from clear to darker, indicates greater significance. For all of the variables, the data collected from each plant were used: crowns, leaflets, flowers and inflorescences, which corresponded to the accumulated number of each of the structures per plant; the foliar area was expressed as cm2/plant; the production corresponded to the accumulate weight of the harvested fruit, expressed as g/plant; the fruits were expressed as the accumulet number of harvested fruits per plant; the leaflet damage corresponded to the accumulated number of leaflets per plant that were affected in some way by a biotic or abiotic factor. 150 Agron. Colomb. 33(2) 2015 FIGURE 2. Correlations between the vegetative and reproductive variable evaluated in the Monterey cultivar until 202 d after sowing. The numbers in the upper row of each square indicate the coefficient of determination (r), and the numbers in the lower row indicate the significance according to the Spearman method. The white color indicates that the correlation was not significant and the gray scale, from clear to darker, indicates greater significance. For all of the variables, the data collected from each plant were used: crowns, leaflets, flowers and inflorescences, which corresponded to the accumulated number of each of the structures per plant; the leaf area was expressed as cm2/plant; the production corresponded to the accumulet weight of the harvested fruit, expressed as g/plant; the fruits were expressed as the accumulet number of harvested fruits per plant; the leaflet damage corresponded to the accumulated number of leaflets per plant that were affected in some way by a biotic or abiotic factor. Crowns Leaflets Leaf area Flowers Inflorescences Leaf damage Production Fruits Production Fruits Leaflet damage Inflorescences Crowns Leaflets Leaf area Flowers /inflorescence Flowers Flowers /inflorescence 0.67085 0.56905 0.36923 0.35829 0.02869 0.13684 0.24137 0.11722 <0.0001 <0.0001 <0.0001 <0.0001 0.7661 0.154 0.0156 0.2226 0.8095 0.51841 0.53685 -0.04529 -0.20396 0.30024 0.26389 <0.0001 <0.0001 <0.0001 0.6385 0.0267 0.0024 0.0053 0.48341 0.43138 0.14143 -0.07499 0.32096 0.28441 <0.0001 <0.0001 0.1405 0.4362 0.0011 0.0026 0.90481 0.22721 -0.21468 0.56605 0.59855 <0.0001 0.017 0.0243 <0.0001 <0.0001 -0.17313 -0.26181 0.49813 0.5223 0.0705 0.0057 <0.0001 <0.0001 0.11952 0.16791 0.19216 0.2136 0.0949 0.0443 -0.19401 -0.321 0.0531 0.0006 0.94205 <0.0001 1 1 1 1 1 1 1 1 1 was weighted for the majority of the variables due to its correlation: number of crowns, number of leaf lets, leaf area, number of inf lorescences, number of f lowers, yield, and number of fruits; while the second principal compo- nent gave a high value to the fruit diameter and individual weight (Fig. 3A). The leaf damage, as a harmful effect, presented negative values on the first principal component. The principal components analysis of the evaluated treat- ments showed that the highest values of the first principal component were seen in the high-tunnel environment with the Monterey cultivar, indicating that these plants present- ed a higher vegetative vigor and a higher yield, followed by the ‘Monterey’ plants found in the open-field system. For its part, the Albion cultivar, in the high-tunnel and open- filed environments, presented the lower values in the first principal component (Fig. 3B). There was a tendency for an increase in the second principal component in the treat- ments of the open-field environment, representing fruits with larger diameters and sizes (Fig. 3B). The individual fruit weight had a negative relationship with the variables of yield and number of fruits, which is ref lected in the figure containing the principal component weight by being in opposing squares (Fig. 3A). This could have been caused by a low number of fruits with a high capacity for filling and photoassimilate capture due to lower sink competition, as compared to a plant with a lot of fruits (Taiz and Zeiger, 2010; Marschner, 2012). The vegetative component of strawberries and other species is important due to the fact that plants with a high vigor 151Grijalba, Pérez-Trujillo, Ruiz, and Ferrucho: Strawberry yields with high-tunnel and open-field cultivations and the relationship with vegetative and reproductive... -1.9-3.9 2.10.1 4.1 6.1 Pr in ci pa l c om po ne nt 2 -3.4 2.6 0.6 -1.4 4.6 A Principal component 1 Pr in ci pa l c om po ne nt 2 -3.4 4.6 2.6 0.6 -1.4 B Principal component 1 -1.9-3.9 2.10.1 4.1 6.1 A-OF A-HT M-OF M-HT cro lef inf afol damage dial yield fto indw FIGURE 3. Principal components in the yield variables evaluated in the strawberry plants until 202 d after sowing. A, weight of the components in each variable; B, principal components coded in accordance with the evaluated treatments. A-OF, ‘Albion’-open field; A-HT, ‘Albion’-high-tunnel; M-OF, ‘Monterey’-open-field; M-HT, ‘Monterey’-high-tunnel. Damage, leaflet damage; indw, individual fruit weight; dial, fruit diameter; cro, number of crowns; lef, number of leaflets; afol, leaf area per plant; inf, number of inflorescences; yield, yield per plant; fto, number of fruits. 11 9 13 3 14 7 16 1 17 5 18 9 20 3 21 7 23 1 24 5 25 9 27 3 28 7 30 1 31 5 32 9 34 3 35 7 37 1 38 5 39 9 41 3 42 7 44 1 45 5 46 9 48 3 Y ie ld ( g/ pl an t) 0 120 100 80 60 20 40 140 D das Y ie ld ( g/ pl an t) 0 120 100 80 60 20 40 140 C 11 9 13 3 14 7 16 1 17 5 18 9 20 3 21 7 23 1 24 5 25 9 27 3 28 7 30 1 31 5 32 9 34 3 35 7 37 1 38 5 39 9 41 3 42 7 44 1 45 5 46 9 48 3 das 11 9 13 3 14 7 16 1 17 5 18 9 20 3 21 7 23 1 24 5 25 9 27 3 28 7 30 1 31 5 32 9 34 3 35 7 37 1 38 5 39 9 41 3 42 7 44 1 45 5 46 9 48 3 Y ie ld ( g/ pl an t) 0 120 100 80 60 20 40 140 B das A-HT M-HT Y ie ld ( g/ pl an t) 0 120 100 80 60 20 40 140 A A-OF M-OF 11 9 13 3 14 7 16 1 17 5 18 9 20 3 21 7 23 1 24 5 25 9 27 3 28 7 30 1 31 5 32 9 34 3 35 7 37 1 38 5 39 9 41 3 42 7 44 1 45 5 46 9 48 3 das 0 90 80 70 60 50 40 30 10 20 100 Lo ss es ( g/ pl an t) 0 90 80 70 60 50 40 30 10 20 100 Lo ss es ( g/ pl an t) los M-OF los M-HT M-HT M-OF los A-OF los A-HT A-HT A-OF FIGURE 4. Yield differences per plant between the strawberry cultivars in each environment (A-B), and yield and fruit loss differences between the environments for each cultivar (C-D). The bars indicate the quantity of harvest fruit losses due to different reasons. HT, high-tunnel; OF, open-field; das, days after sow; los, losses. M, Monterey cultivar; A, Albio cultivar. 152 Agron. Colomb. 33(2) 2015 have the ability to produce more photoassimilates and, therefore, a higher ability to produce f lowers and fruits (Albregts, 1968; Lacey, 1973; Cocco et al., 2011). Although there is competition for assimilates between the vegetative and reproductive components, adequate vegetative growth after transplanting must be ensured in order to have sus- tained yield (Shaw, 1993), which is vital in tropic conditions due to the year-round production that occurs there. At the statistical level, the yield presented an interaction between the evaluated factors (Tab. 1) because the ‘Mon- terey’ had a higher production in the high-tunnel system, as compared to the open-field system (P≤0.05), while the ‘Albion’ did not have significant differences between the two environments. FIGURE 5. Mean weight of the harvested strawberry losses in each environment (mean of the two cultivars) and its relationship with the precipitation. HT, high- tunnel; OF, open-field; das, days after sow. Lo ss es ( g/ pl an t) 0 60 50 40 30 10 20 70 11 9 13 3 14 7 16 1 17 5 18 9 20 3 21 7 23 1 24 5 25 9 27 3 28 7 30 1 31 5 32 9 34 3 35 7 37 1 38 5 39 9 41 3 42 7 44 1 45 5 46 9 48 3 das 0 100 80 60 40 20 120 P re ci pi ta tio n (m m ) mm OF HT FIGURE 6. Mean daily air temperature and relative humidity registered in the high-tunnel and open-field systems during the harvest period. HT, high-tunnel; OF, open- field; das, days after sow. TABlE 1. Yield during 54 weeks of harvesting in Albion (A) and Monterey (M) cultivars established in open-field (OF) and high-tunnel (HT) systems. Cultivar (CV) Yield (g/plant) Fruits (#/plant) losses (%) Individual fruit weight (g/fruit) Diameterb (cm/fruit) A 2056.63 131.70 13.12 18.08 3.22 M 2859.63 196.24 11.91 16.83 3.19 F-test *** *** NS ** NS Environment (ENV) OF 2394.36 163.01 16.61 18.34 3.33 HT 2521.89 164.93 8.42 16.56 3.07 F-test NS NS *** *** *** CV x ENV * NS NS NS NS CV (%)a 6.71 6.46 12.72 6.02 2.72 *, **, *** Significance with P≤0.05, P≤0.01 and P ≤0.001, respectively. NS , not significant differences. a Coefficient of variation corresponding to each analysis of variance. b Mean diameter of the fruits was calculated with the data registered until 202 das. R el at iv e hu m id ity ( % ) 0 100 80 60 40 20 120 das Te m pe ra tu re ( °C ) 11 9 13 0 14 1 15 2 16 3 17 4 18 5 19 6 20 7 21 8 22 9 24 0 25 1 26 2 27 3 28 4 29 5 30 6 31 7 32 8 33 9 35 0 36 1 37 2 38 3 39 4 40 5 41 6 42 7 43 8 44 9 46 0 6 8 10 12 14 16 18 20 22 24 % OF % HT T° OF T° HT 153Grijalba, Pérez-Trujillo, Ruiz, and Ferrucho: Strawberry yields with high-tunnel and open-field cultivations and the relationship with vegetative and reproductive... The production peaks of the ‘Monterey’ were higher than those of the ‘Albion’ (Fig. 1A-B), results that agree with the reports for these materials in their respective patents, which describe ‘Monterey’ as a cultivar with a higher vegetative vigor and yield than ‘Albion’ (Shaw and Larson, 2006; Shaw and Larson, 2009). In the ‘Monterey’, the production peaks were more evident and the two peaks that were registered over the course of the year were separated by approximately 5 months, a time period that differed from those reported by other authors who have stated that these peaks are seen every 3 months (Hancock, 1999; Kirschbaum and Hancock, 2000). The high-tunnel environment produced a higher yield in the ‘Monterey’, as compared with the production obtained in the open-field system, principally due to a reduction in losses (Tab. 1; Fig. 4B). The losses increased in the rainy seasons (Fig. 5), and mainly resulted from rot caused by the phytopathogen Botrytis cinerea. This beneficiary effect generated by high-tunnels has been reported in different locations around the world (Xiao et al., 2001; Kadir et al., 2006; Carey et al., 2009; Lamont, 2009). There was also a reduction in losses for the ‘Albion’ in the high-tunnel system; however, the yield was similar to the yield seen in the open-field system. This result, along with a smaller fruit size (Tab. 1), indicated the disadvantages that can be seen in high-tunnel conditions. The possible causes for this negative effect seen in high-tunnels include the plant damaged caused by the incidence of powdery mildew and deficiency of calcium. The latter results in leaf tip burning, a symptom that was higher in ‘Albion’, a cultivar catalogued as being susceptible to this problem (Krikke, 2011). The plants in the high-tunnel system had an increase in the incidence of this disorder due to the fact that their rapid growth, which has also been reported as a cause for increasing this problem, results in a higher demand for nutrients and a misbalance between the aerial and radicular parts (Saure, 1998; Palencia et al., 2010). The increase in the air temperature, the decrease in the relative humidity in the high-tunnel (Fig. 6), and the f luctuation of these factors during the day also contributed to the presence of the symptoms of calcium deficiency, causing a higher stomatal closure, which affects the transport of this nutrient to new leaves (Krikke, 2011), more so if the fact that its transport is mainly via the xylem in the transpira- tion process is taken into account (Taiz and Zeiger, 2010; Marschner, 2012). Among the symptoms of calcium deficiency, a reduction in fruit size is also seen (Nestby et al., 2005), which, together with an increase in stomatal closure resulting from a water deficit, can decrease yield due to the fact that the water needed to optimize fruit filling is not provided (Grant et al., 2012). According to the analysis of the soils, the high-tunnel system presented a texture with more clay (45% clay, 35% loam and 20% sand), as compared with the texture of the open-field system (30% clay, 50% loam, and 20% sand). Clay soils reduce evaporation and transpiration due to a chemical interaction with water (Bellingham, 2014) and, in general, present a higher capacity for moisture reten- tion. Nonetheless, the increase in the air temperature and the decrease in the relative humidity that were seen in the high-tunnel system may have promoted a water deficit in the strawberry plants despite irrigation applications that were similar in the two environments, which could explain the increase in the problems of calcium deficiency and fruit filling. Conclusions The yield of the strawberry plants presented positive cor- relations with all of the vegetative and reproductive vari- ables, except for the individual weight of the fruits, which presented a negative relationship. ‘Monterey’ presented a higher yield than ‘Albion’ due to a higher vegetative vigor represented in all of the evalu- ated variables, as well as a high number of reproductive structures. The technology of the high-tunnel system has the potential to increase yield through a reduction of losses and of dam- age mainly caused by precipitation; however, a preventative control of disease such as powdery mildew, a differential management in the fertigation and the selection of cultivars that are suitable for this environment are necessary, as seen in the case of ‘Monterey’. 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