EFFECTS OF SOME APPLICATIONS ON STRAWBERRY SEEDLING PRODUCTIVITY AND QUALITY

With the development of strawberry cultivated area in China, the demands for high-quality strawberry seedlings are increasing year by year. The research on the evaluation index of strawberry seedlings is needed to ensure the quality of the seedlings. This study aimed to establish an optimal index model of strawberry seedlings to improve the accuracy of seedlings evaluation. In this study, 320 seedlings of 'Benihoppe' strawberry seedlings growing for 40 days were taken as the materials. Based on the determination of 16 individual indicators including the growth of aboveground and underground parts, fresh weight, and dry weight, we firstly conducted the membership function corresponding to single indicator. Then the comprehensive evaluation index of strawberry seedlings was calculated using weighted fuzzy evaluation method. Furthermore, the key indicators out of the 16 indicators which were filtered out by means of the principal component analysis method were combined into different index models of strawberry seedlings. The correlation analysis between the comprehensive evaluation index and seedling index models was done and finally the optimal seedling index model was selected and verified. The results showed that there were significant differences in 16 indices of 320 randomly selected strawberry seedlings. The comprehensive evaluation index of strawberry seedlings was in the range of 0.165-0.817, indicating that the comprehensive evaluation index could totally reflect the quality of seedlings and could be used as the evaluation basis. The 16 individual indices of strawberry seedlings were classified into three principal components, including aboveground related indicators, underground related indicators, and the pigment indicators. The cumulative contribution rate of three principal components was 79.7%. Twenty-seven seedlings index models were combined by randomly selecting three indices with a large contribution value from each principal component. Five strawberry seedlings index mo-dels were selected from 27 models due to the highest correlation with the comprehensive evaluation index. Among them, the model "aboveground dry weight×root surface area×chlorophyll a" was identified as the optimal one to evaluate the quality of strawberry seedlings, due to the highest correlation with the comprehensive evaluation index. The correlation coefficient of between strong seedling index and comprehensive evaluation index in three strawberry variety 'Benihoppe', 'Kantoseika' and 'Sweet Charlie' were 0.879, 0.924, and 0.975, respectively. According to the comprehensive evaluation index, the quality of strawberry seedlings were classified into three grades: grade Ⅰ (comprehensive evaluation index ≥0.5, seedling index ≥4.0) with high-quality seedlings; grade Ⅱ (comprehensive evaluation index 0.3-0.5, seedling index 0.5-4.0) with qualified seedlings; grade Ⅲ (comprehensive evaluation index ≤0.3, seedling index ≤0.5) with weak seedlings. The results provided a theoretical basis and scientific method for the evaluation of the health status of strawberry seedlings or other fruits and vegetable seedlings.

BackgroundThe agronomic quality of cutting-propagated strawberry seedlings is a critical determinant of subsequent field performance and economic returns in the annual production of fresh-market strawberries. Although far-red light (FR) has been well established as a key regulator of plant architecture and productivity in many horticultural crops, its specific physiological roles during the strawberry seedling establishment stage remain poorly understood. Thus, investigating whether end-of-day far red (EOD-FR) light treatment can effectively enhance the growth vigor and overall development of strawberry runners addresses a significant knowledge gap, with direct implications for commercial seedling production systems.MethodsThe experiment investigated the effects of 0 (CK), 3 h, 6 h, and 9 h EOD-FR durations on strawberry cuttings (Fragaria × ananassa Duch. cv. Benihoppe). The 60-d period experiment was conducted in a solar greenhouse, employing a completely randomized block design. The sampling was carried at 30 d and 60 d to assess physiological and morphological responses of strawberry seedlings.ResultsCompared with the control (CK), 6 h EOD-FR supplementation markedly enhanced seedling growth, including increases in height, leaf area, petiole diameter and length, biomass accumulation, root development and vigor index. In addition, anatomical observations revealed that while prolonged EOD-FR exposure led to reduction in leaf thickness, the 6 h EOD-FR increased the number of vascular bundles in petioles and accelerated floral bud differentiation. The physiological analysis showed that 6 h EOD-FR supplementation enhanced net photosynthetic rate and stomatal conductance, and water use efficiency. This was observed alongside increased activities of antioxidant enzyme and greater accumulation of osmolytes, including free amino acids, soluble sugars, and proteins. Hormonal profiling indicated that 6 h EOD-FR increased the IAA, Brassinosteroids, and ABA levels in leaves and petioles. However, the marked increase of ABA content and reduce of GA₃ content were only found in shoot apices. Based on membership function values and principal component analysis, the order of treatment performance (6 h > 3 h > CK > 9 h) was consistent across both 30-d and 60-d experimental durations.ConclusionIn summary, supplementation with 6 h EOD-FR optimizes photosynthetic performance, strengthens antioxidant capacity, regulates hormone balance, and promotes nutrient accumulation in strawberry seedlings, ultimately leading to enhanced growth and stimulated floral induction.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12870-025-08092-3.

In Brazil, strawberry production is conditioned by the importation of seedlings from different countries, with variable levels of adaptation, different cold requirements and high costs of the introduced material. The national production of seedlings of good genetic, physiological and phytosanitary quality, constitutes a viable alternative for Brazilian producers dedicated to this productive activity. The objective of this work was to evaluate the effect of the application of different concentrations and times of application of calcium prohexadione (ProCa) (growth retardant in various cultivated species), on the magnitude changes of the propagation structures, growth and development of strawberry seedlings cv. Pircinque, the productive behavior and the quality of the fruit. The experiment was carried out in the Agricultural Sciences Center of the Santa Catarina State University (CAV-UDESC) in Lages / SC (Brazil), with a 5 x 2 factorial design, five concentrations of prohexadione calcium (0, 100, 200, 300 and 400 mg L-1) and two periods of aplication (20 and 30 days after the planting of the rooting stolon). In the seedlings, the following were evaluated: number of leaves, crown diameter, height seedling and leaf area. The parameters evaluated in the strawberry plants were: number of fruits per plant, average fruit weight, total fruit weight, dry weight of leaves and crowns, during the cycle 2019/2020. Additionally, firmness, total soluble solids (TSS), titratable. acidity (TA) and ratio were evaluated. The application of ProCa significantly reduces vegetative growth and induces an increase in physiological responses in 'Pircinque' strawberry seedlings, such as leaf area and height for both application periods. On the other hand, ProCa concentrations did not influence the number of fruits and the mass of fruits per plant, nor the quality parameters of the fruit, with the exception of firmness, where it was favored by the concentration of 400 mg L-1. The results were related to the application time factor, where at 20 DAT the highest values of the morphological variables of the seedlings and plants were presented and on the contrary, applications at 30 DAT decrease the number of commercial fruits per plant.

A produção de morango é sazonal, e os melhores preços dos frutos são obtidos fora da estação. Buscando obter frutos fora da estação, o objetivo deste trabalho foi avaliar o efeito da vernalização em mudas de cinco cultivares de morangueiro. As mudas foram produzidas no sistema de vasos suspensos. O delineamento experimental utilizado foi blocos ao acaso em fatorial 5x2x4, com cinco cultivares ("IAC-Campinas", "Dover", "Sweet Charlie", "Cartuno" e "Oso Grande"), dois tratamentos (com e sem vernalização das mudas) e quatro tempos, com quatro repetições. Para vernalização, as mudas foram levadas para câmara fria à temperatura de 10+2°C e fotoperíodo de 8h de luz dia-1 durante 28 dias, e em seguida transplantadas. Foram avaliadas as percentagens de sobrevivência, florescimento, frutificação, emissão de estolhos, a massa e o número de frutos produzidos por planta. A sobrevivência de mudas não foi afetada pela vernalização. Houve efeito significativo no florescimento e na frutificação das plantas vernalizadas. O estolonamento de plantas foi mais precoce nas mudas vernalizadas. Para todas as cultivares e tratamentos, a produção de frutos foi insignificante e comercialmente inviável.

The strawberry (Fragaria × ananassa Duch.) is an important fruit crop cultivated worldwide for its unique taste and nutritional properties. One of the major risks associated with strawberry production is cold damage. Recently, melatonin has emerged as a multifunctional signaling molecule that influences plant growth and development and reduces adverse consequences of cold stress. The present study was conducted to investigate the defensive role of melatonin and its potential interrelation with abscisic acid (ABA) in strawberry plants under cold stress. The results demonstrate that melatonin application conferred improved cold tolerance on strawberry seedlings by reducing malondialdehyde and hydrogen peroxide contents under cold stress. Conversely, pretreatment of strawberry plants with 100 μM melatonin increased soluble sugar contents and different antioxidant enzyme activities (ascorbate peroxidase, catalase, and peroxidase) and non-enzymatic antioxidant (ascorbate and glutathione) activities under cold stress. Furthermore, exogenous melatonin treatment stimulated the expression of the DREB/CBF—COR pathways’ downstream genes. Interestingly, ABA treatment did not change the expression of the DREB/CBF—COR pathway. These findings imply that the DREB/CBF-COR pathway confers cold tolerance on strawberry seedlings through exogenous melatonin application. Taken together, our results reveal that melatonin (100 μM) pretreatment protects strawberry plants from the damages induced by cold stress through enhanced antioxidant defense potential and modulating the DREB/CBF—COR pathway.

The use of locally grown transplants in Florida strawberry (Fragari×ananassa Duchesne) production has increased since the release of the cultivar Sweet Charlie by the University of Florida in 1992. Previous research has shown that nursery region can influence production patterns of other strawberry cultivars through differences in photoperiod and temperature exposure. Transplants of `Sweet Charlie' strawberry (bareroot and plug plants) from sources representing northern (Canada, Massachusetts, Oregon), southern (Alabama, Florida) and mid latitude (North Carolina) transplant production regions were compared for plant vigor, production, and pest incidence at Dover, Fla. in 1995-96 and 1996-97. Total fruit production was not significantly different forplants among the plant source regions in 1995-96, but total yield from southern source plants in 1996-97 was significantly lower than northern and mid latitude plant sources. Monthly production of marketable fruits varied among the three plant source regions in December, January, and February, during which time market prices fell 46% in 1995-96 and 56% in 1996-97. Plants from northern and mid latitude sources produced significantly greater fruit yield in December than plants from southern sources. Differences among plant sources were detected for early flowering, initial crown size, incidence of foliar disease, arthropod pests, mortality, and fruit weight. Geographic location of strawberry transplant sources influenced fruiting patterns and other components that may affect profitability of `Sweet Charlie' strawberry production in west central Florida.

Humic acids (HA), amino acids (AA) and vitamins can increase plant growth; however, there are still few studies that determine the ideal concentration for use in lettuce (Lactuca sativa L.) production. Research was conducted to evaluate the effects of HA enriched with sources and levels of AA and vitamins on lettuce seedlings morphology and quality. Two experiments were conducted in a completely randomized design with four replicates. The first experiment had 16 treatments, 3 × 5 + 1 factorial design, the first factor was betaine, glycine and proline used in the HA enrichment, and second factor five concentrations of AA (0, 0.5, 1.0, 1.5, and 2.0 g L-1), plus the control, without HA and AA. The second experiment had 21 treatments, 4 × 5 + 1 factorial design, the first factor was the use of four vitamins (A, E, B1 and B2) in the enrichment of HA, while the second factor was composed of five concentrations of each vitamin (0, 0.5; 1.0, 1.5, and 2.0 g L-1) plus the control, without HA and vitamins. The application of HA and HA+AA promote the improvement in the seedling’s morphology and quality, while the application of the HA+vitamins negatively affected the morphology, reducing seedling quality.

Strawberry production presents special challenges due the plants’ shallow roots. The rooting stage of strawberry is a crucial period in the production of this important crop. Several amendments have been applied to support the growth and production of strawberry, particularly fertilizers, to overcome rooting problems. Therefore, the current investigation was carried out to evaluate the application of biological nanofertilizers in promoting strawberry rooting. The treatments included applying two different nanofertilizers produced biologically, nano-selenium (i.e., 25, 50, 75, and 100 mg L−1) and nano-copper (i.e., 50 and 100 mg L−1), plus a control (untreated seedlings). The rooting of strawberry seedlings was investigated by measuring the vegetative growth parameters (root weight, seedling weight, seedling length, and number of leaves), plant enzymatic antioxidants (catalase, peroxidase, and polyphenol oxidase activity), and chlorophyll content and its fluorescence and by evaluating the nutritional status (content of nutrients in the fruit and their uptake). The results showed that the applied nanofertilizers improved the growth, photosynthetic pigments, antioxidant content, and nutritional status of the seedlings compared to the control. A high significant increase in nutrient contents reached to more than 14-fold, 6-fold, 5-folf, and 4-fold for Cu, Mn, N, and Se contents, respectively, due to the applied nanofertilizers compared with the control. The result was related to the biological roles of both Se and CuO in activating the many plant enzymes. Comparing the Se with the CuO nanofertilizer, Cu had the strongest effect, which was shown in the higher values in all studied properties. This study showed that nanofertilizers are useful to stimulate strawberry seedling growth and most likely would also be beneficial for other horticultural crops. In general, the applied 100 ppm of biological nano-Se or nano-CuO might achieve the best growth of strawberry seedlings under growth conditions in greenhouses compared to the control. Along with the economic dimension, the ecological dimension of biological nanofertilizers still needs more investigation.

This study was conducted to investigate productivity of strawberry plants as affected by propagation method and cultivation system. Transplants propagated by cutting propagation and pinning propagation were planted and grown for a whole production period in soil and hydroponic cultivation systems. Growth parameters, fruit productivity, and fruit quality were measured during the whole harvest period. The results showed that propagation method and cultivation system had significant effects on vegetative growth of strawberry plants. Total fruit yield per plant and average fruit weight per fruit during the whole harvest period were significantly lower in the plants grown in soil cultivation system. Total unmarketable fruit ratio was significantly greater in soil cultivation system than that in hydroponic cultivation system. Small fruits were the primary unmarketable fruits in soil cultivation system, while malformed fruits were the primary unmarketable fruits in hydroponic cultivation system. The overall high quality of fruit was found in February, and the plants cultivated in hydroponic cultivation system had higher quality of fruit as compared with that in soil cultivation system. It is concluded that cutting propagation is better than pinning propagation, and hydroponic cultivation system is better than soil cultivation system for fruit productivity of strawberry.

Precisely identifying missing virus-free strawberry mother plants in nutrient pots post-transplantation is crucial for optimizing seedling management and maximizing yields in glass greenhouses. Thus, we present an automated method for detecting and counting missing seedlings based on SSP-MambaNet. Challenges in this process include the variable growth morphology of seedlings and complex environmental conditions in the greenhouse. Our approach starts with SPDFFA (Spatial-to-Depth Feature Fusion Attention) to enhance feature representation while retaining critical information, ensuring the preservation of key details. Additionally, the multi-scale CVSSB(Complex Visual State Space) and CVSSB-E(Expanded CVSSB) modules combine multi-scale and multi-directional spatial features, augmenting the model's capacity to recognize inter-image dependencies. Secondly, the MPDIoU is a novel loss function to tackle the optimization challenge of bounding boxes with similar shapes but different sizes, which enhances the accuracy of localizing strawberry seedlings and nutrient pots. Finally, Distance Intersection over Union is utilized for establishing a belongingness relationship between strawberry seedlings and pots, accurately identifying missing seedlings and counting the corresponding pots.Experimental results demonstrate that SSP-MambaNet achieves 94.9 %in average precision, 92.8 ​% in recall rate,88.1 ​% in precision, and 90.4 ​% F1 score for strawberry seedlings and pots. It outperforms the YOLOv7 by 4.7 ​% in average precision, and 2.6 ​% in recall rate while reducing 66.7 f/s in FPS. Furthermore, the proposed method shows 94.29 ​% accuracy in detecting missing seedlings and 97.14 ​% accuracy in counting nutrient pots with missing seedlings. These results showcase its effectiveness in improving overall seedling quality and providing timely replanting guidance in glass greenhouses.

As one of the most salt-sensitive crops, strawberry production is severely limited by salt stress. γ--aminobutyric acid (GABA) has been reported to play an important role in the immune response of plants. In this study, the physiological and transcriptomic changes in strawberry seedlings treated with GABA under salt stress were investigated to explore the effect of GABA on salt tolerance. The results showed that exogenous GABA maintained high osmolyte levels, increased antioxidant capacity, and decreased the ROS levels in strawberry leaves under salt stress; the MDA was reduced by 3.27–31.46%, with 10 mM being the most significant effect; the total (Spd + Spm)/ Put ratio was upregulated after GABA treatments. More strikingly, the plants treated with 10 mM GABA significantly increased chlorophyll content and net photosynthetic rate in salt-stressed plants, which was explained by the transcriptomic data showing that the expression levels of most of chlorophyll metabolism and photosynthesis-related genes were upregulated. Furthermore, 38 potential TFs belonging to the WRKY, AP2/ERF, and MYB families were identified that may be positively involved in GABA-induced salt tolerance. Co-expressed network analysis revealed that some of these TFs, such as RAP2.7, WRKY46, and MYB306, were significantly positively correlated with chlorophyll metabolism. These findings provide an important basis for the use of GABA in the breeding of strawberry resistant to salt stress.

Bacillus amyloliquefaciens strains control strawberry anthracnose through antagonistic activity and plant immune response intensification

Salt stress could lead to plant growth barriers and crop yield reduction. Strawberries are sensitive to salt stress, and improving salt tolerance is important for strawberry production. This study aimed to explore the potential of hydrogen-rich water (HRW) to enhance salt tolerance in strawberries. Through pot experiments, we investigated how HRW affects plant growth, ion absorption, osmotic stress, oxidative stress, antioxidant enzyme levels, hormone levels, and root endophytic bacteria in strawberry seedlings under salt stress. The results showed that under 100 mM NaCl treatment, 50% and 100% HRW treatments significantly increased strawberry biomass by 0.29 g and 0.54g, respectively, wherein, 100% HRW significantly increased the shoot and root length by 15.34% and 24.49%, respectively. In addition, under salt stress the absorption of K+ by strawberry seedlings was increased with the HRW supplement, while the absorption of Na+ was reduced. Meanwhile, HRW treatment reduced the transfer of Na+ from root to shoot. Furthermore, under salt stress, HRW treatment increased the relative water content (RWC) by 12.35%, decreased the electrolyte leakage rate (EL) by 7.56%. HRW modulated phytohormone levels in strawberry seedlings, thereby alleviating the salt stress on strawberries. Moreover, HRW was found to promote plant growth by altering the diversity of bacteria in strawberry roots and recruiting specific microorganisms, such as Tistella. Our findings indicate that HRW could help restore the microecological homeostasis of strawberry seedlings, thus further mitigating salt stress. This study provides a novel perspective on the mechanisms by which HRW alleviates salt stress, thereby enriching the scientific understanding of hydrogen's applications in agriculture.

This study was undertaken during the seasons of 2019-2020. The xperiment examines the impact of Humic acid and Seaweed extract at three concentrations on growth, flowering and yield as a foliar spray and their interactions on growth, chemical composition, production and quality of strawberry at two strawberry cultivars (Fragaria X ananassa Duch.) Albion and Rubygem.The results showed that the higher leaf dry weight, root dry weight, number of flowers, yield per plant, with Rubygem, higher value of Nitrogen % in leaf, phosphorus %, anthocyanin (Mg/100g F.Wt.) observed for Rubygem. As well as the higher value of root dry weight (g. plant -1), yield per plant (g. Plant-1) Nitrogen % in leaf recorded with Humic acid, treatment. Moreover, the combined treatment between organic fertilizers and two strawberry cultivars exhibited the significant effect in root dry weight (g. plant-1), Nitrogen % in leaf, phosphorus (%), number of flowers, yield per plant (g. plant-1) and anthocyanin (Mg/100g F.Wt.). As well as the combination between organic fertilizers and concentrations and organic fertilizers, two strawberry cultivars and concentrations had significantly effect in all the studied traits.

La producción de frutilla en Paraguay es realizada por pequeños productores, usando escasa tecnología y obtención de baja productividad, con la necesidad de ampliar los genotipos y la tecnología utilizada. El objetivo de esta investigación fue evaluar la calidad de frutos de genotipos de frutilla en función a la vernalización. El diseño utilizado fue el de bloques completos al azar con arreglo factorial 14x2. Los factores estuvieron constituidos por los genotipos y la vernalización con 15 plantas por tratamiento y tres repeticiones. Las mudas fueron mantenidas en cámara fría a 5°C, con 8 horas luz artificial y 16 de oscuridad por un periodo de 25 días. Se utilizaron cinco frutos por tratamiento y fueron evaluadas la cantidad de sólidos solubles totales, acidez titulable, relación de sólidos solubles totales con acidez titulable, relación longitud/diámetro, relación: diámetro del cáliz/diámetro del fruto, longitud del pedúnculo y pérdida de masa en postcosecha. Los datos obtenidos fueron sometidos a análisis de varianza en esquema factorial simple y las medias comparadas por el test de Tukey al 5% de probabilidad de error. La vernalización de las mudas no afectó la forma de los frutos de frutilla ni el contenido de sólidos solubles totales, pero aumentó el porcentaje de ácido cítrico. Así mismo, aumentaron la longitud del pedúnculo de la planta y la extensión del cáliz del fruto. Por otro lado, la vernalización disminuyó la pérdida postcosecha de masa fresca, pero no afectó la conservación de frutos a 5ºC. Los genotipos Festival y Florida Eliane pueden ser recomendados para consumo in natura y los genotipos Dover y Oso Grande para industria.