June-bearing Strawberry Cultivars Research Articles

Comparison of field performance and fruit quality among newly released Italian June-bearing strawberry cultivars

The aim of this study was to compare newly released June-bearing strawberry cultivars (?Quicky?, ?Sandra?, ?Lofty?, ?Nadja? and ?Aprica?) in terms of their phenology, vegetative growth, productivity and fruit quality to identify their potential for wider cultivation. A field study was conducted in a strawberry plantation established in July 2020 in double rows on beds covered with black polyethylene foil (Sid, Serbia). The cultivars were evaluated in 2021-2022 for their flowering and ripening time, productivity, plant growth, biometrical and nutritional fruit traits (soluble solids content - SSC, total acids - TAs, vitamin C, total anthocyanins - TACY, total phenolics - TPC and total antioxidant capacity - TAC). The cultivar ?Quicky? started to ripen earliest, while ?Aprica? was the latest in both experimental years. The number of branch crowns per plant was significantly higher in ?Sandra? and ?Lofty?, whereby ?Sandra? had also the highest number of leaves per rosette (41.5) in comparison with the other tested cultivars. The cultivar ?Aprica? was superior in terms of productivity (1061 g/plant and 4.67 kg/m2), fruit weight (29.9 g) and fruit shape index (1.15). Contrary to this, ?Nadja? was the least productive cultivar (608 g/plant and 2.68 kg/m2). The cultivars ?Lofty? and ?Sandra? showed the highest SSC values and were also characterized by a considerably high level of TPC (1.29 mg GAE eq g-1 FW) and TACY (24.4 mg pg-3-g eq 100 g-1 FW), respectively. Variability among the tested cultivars could serve as an important criterion for the selection of new high-performing cultivars for a given growing region.

Effects of different substrates on the runner production of the June-bearing strawberry cv. 'Senga Sengana'

Producing high-quality daughter plants of the June-bearing strawberry is very important for fruit production around the year. This study was conducted to investigate the impacts of different substrates on the runner production of the June-bearing strawberry cultivar ‘Senga Sengana’. In April 2019, strawberry mother plants were planted while the daughter plants were examined November 2019. The nursery trial field was separated into four substrate treatments, each included ten strawberry mother plants, approximately homogeneous. The place where the mother plants were planted was with the same substrate (PTS substrate “Pindstrup”) and separated from the field for the rooting of the daughter plants. In the field for the rooting of the daughter plants, four types of substrates were used: The first substrate treatment (S1) (soil 50% – decomposed manure 50%); the second substrate treatment (S2) (PTS substrate “Pindstrup” with modules (pots) with a volume of 200 mL/daughter plant); the third substrate treatment S3 (river sand 50% – soil 50%); lastly, substrate treatment four S4 (sawdust 100%). During the research, several parameters were determined for the mother plants: the crown diameter, number of flowers, number of runners per plant, number of daughter plants per runner and number of daughter plants per plant. The examination of some of the qualitative parameters was also performed on the daughter plants: the crown diameter, root length and number of roots. Based on these parameters, the daughter plants were categorised according to the standards: A++, A+, A, A–, OS (out of the standard). From the examined results, it was concluded that S3 formed the largest number of daughter plants at 123 (A++ 19.1, A+ 45.1, A 28.7, A– 17.8, OS 12.3 plants); S2 formed 69.4 daughter plants, but with the highest standards (A++ 34.7, A+ 33.6, A– 1.1 plants); S4 formed 74.8 daughter plants (A++ 26.2, A+ 30.4, A 14 OS 4.2 plants), while S1 formed 62 daughter plants and showed the worst results for both the number of plants and the standard (A+ 7, A 3.8, A– 0.8, OS 50.4 plants).

Local CO2 Application within Strawberry Plant Canopy Increased Dry Matter Production and Fruit Yield in Summer and Autumn Culture

ABSTRACT June-bearing strawberry cultivars have been widely grown in Japan. Since they are harvested in winter and spring, little produce is available in summer and autumn. To achieve stable year-round supply, we need to expand the production area of ever-bearing cultivars. Here, we examined whether it is possible to increase dry matter (DM) production and fruit yield by increasing the CO2 concentration within the plant canopy through local application to promote photosynthesis in summer and autumn protected culture. We investigated the CO2 concentration in the plant canopy, DM production characteristics, yield characteristics, fruit quality, projected leaf area, cumulative light interception, and light use efficiency. We confirmed that the CO2 concentration within the plant canopy could be increased in summer and autumn (Control; 398 ppm, CO2; 1280 ppm), significantly increasing DM production and total yield (Control; 349 g, CO2; 447.5 g). We consider that local application of CO2 increased the projected leaf area and thus cumulative light interception. This method may help to increase fruit yield in summer and autumn protected culture.

Wintering Index and Yield Traits for Early, Mid, and Late Season Strawberry for Colder Climates

ABSTRACT In temperate climatic regions where severe winter conditions persist, the winter hardiness and fruit yield of strawberry cultivars vary greatly in perennial production systems. A 4-year study was carried out to investigate the wintering ability of different June-bearing strawberry cultivars in the cold semi-arid continental climate of Manitoba between 2015 and 2018. The wintering index and yield traits of early, mid, and late season strawberry cultivars were evaluated. Six different cultivars tested in each year. ‘Wendy,’ ‘Kent’, and ‘Cabot’ were common in each year. Mid-season cultivar ‘Kent’ and ‘Mira’ yielded significantly (p< .05) higher with greater wintering index compared to early and late season cultivars within each trial and across 4 years. Low winter temperatures with less snow on grounds establish pronounced effect on early season cultivars wintering index. A significant variation for temperatures was recorded for the months within and between years.

Genetic Diversity and Population Structure Analysis of Ever-Bearing and June-Bearing Strawberry Cultivars Using SSR Markers

Genetic Diversity and Population Structure Analysis of Ever-Bearing and June-Bearing Strawberry Cultivars Using SSR Markers

Genetic Diversity and Population Structure Analysis of Ever-Bearing and June-Bearing Strawberry Cultivars Using SSR Markers

This study was carried out to select simple sequence repeat markers (SSR), to identify a DNA profile database, and to analyze the population structure of 28 strawberry cultivars (Fragaria × ananassa Duch.) including 22 cultivars of Ever-bearing and 6 of June-bearing strawberry types using SSR markers. We used 10 SSR markers to analyze the genetic diversity and population structure of 28 strawberry cultivars. A total 135 alleles were detected with an average of 13.5 per locus. The genetic diversity (1-D) of 28 strawberry cultivars ranged from 0.53 (EMFn226) to 0.89 (FxaHGA02P13), with an average of 0.79. Indices of evenness ranged from 0.57 to 0.83 (average 0.71). Analysis of the distribution of 28 strawberry genetic groups with different K values was performed. With K = 2, it was confirmed that the 28 strawberry genetic groups were divided into two. These 10 SSR makers will be useful to identify and differentiate between Ever-bearing and June-bearing strawberry cultivar.

Variation of bioactive compounds content of 14 oriental strawberry cultivars

Variation in bioactive compounds content was assessed in antioxidant rich June-bearing strawberry cultivars. Ascorbic acid, anthocyanin, and ellagic acid content were analyzed in ripe fruits of 14 cultivars. The bioactive content in strawberry fruit was found to vary significantly among cultivars and from year to year. The highest ascorbic acid content was found in ‘Sugyeong’. The ‘Red Pearl’ and ‘Sachinoka’ had three to fourfold higher amounts of pelargonidin 3-glucoside than other cultivars. For cyanidin 3-glucoide and pelargonidin 3-rutinoside, two other characterized anthocyanins, ‘Dahong’ and ‘Keumhyang’ had the highest contents among all the tested cultivars. The ellagic acid content of ‘Dahong’ was generally all within the upper ranges. These results can be used for the validation of fruit antioxidant capacity and in addition, provide useful information for breeding programs looking to enhance the antioxidant capacity in strawberry fruit.

Changes in physicochemical characteristics during fruit development in June-bearing strawberry cultivars

Changes in physicochemical characteristics were investigated during fruit development in ‘Maehyang’, ‘Seolhyang’, ‘Keumhyang’, ‘Akihime’, and ‘Red Pearl’ strawberries. Fresh weights and color parameters of strawberry fruits changed significantly during the fruit development in all cultivars. Fruit shapes of ‘Maehyang’ and ‘Akihime’ were conical, with an index of length to width being 1.5 and that of ‘Seolhyang’, ‘Keumhyang’, and ‘Red Pearl’ were cordate, the index being 1.3. Firmness decreased as the fruit developed in all cultivars. Contents of sugars, organic acids, ascorbic acid, and anthocyanin increased as the fruits developed while the ellagic acid content decreased. Sugars, ascorbic acid, and anthocyanin contents of ‘Maehyang’, ‘Seolhyang’, and ‘Keumhyang’ were higher than those of ‘Akihime’ and ‘Red Pearl’. Results indicate that newly-bred Korean strawberry cultivars containing high levels of bioactive compounds were superior to major Japanese cultivars that have been broadly cultivated in East Asian countries.

Changes in Fruit Physicochemical Characteristics by Fruit Clusters in June-bearing Strawberry Cultivars

Three Korean-bred strawberry cultivars 'Maehyang', 'Seolhyang', and 'Keumhyang', and a Japanese cultivar 'Tochiotome' were grown in a greenhouse and their physicochemical characteristics were investigated. Fruit weight of 'Seolhyang' and 'Keumhyang' in the first and second fruit clusters were greater than those of other cultivars and that of 'Tochiotome' was the greatest in the fifth fruit cluster. Fruit firmness generally decreased at later fruit clusters, and was the lowest in 'Seolhyang'. The sugars/organic acids ratios in the first and third fruit clusters of 'Maehyang' were 4.9 and 8.0, respectively, representing the highest values among all cultivars. The ascorbic acid content was the greatest in the second fruit cluster for 'Seolhyang', 'Keumhyang', and 'Tochiotome' cultivars and that of 'Maehyang' was the greatest at the third fruit cluster. The anthocyanin content was higher in later fruit clusters and was the highest in 'Keumhyang' overall. Results indicate that Korean cultivars bred for the plastic protected culture, which are intended for very early harvest, showed more desirable physical characteristics in the first and second fruit clusters, while the content of anthocyanin was greater in the fruits from later fruit clusters.

Influence of short day treatment on autumn fruit production of June-bearing strawberry cultivars

Short-day (SD) strawberry cultivars were grown in 2008 and 2009 fall each year to evaluate effects of short-day (SD) treatment on flowering and fall fruit production in the high elevation of South Korea. In 2008, daughter plants of six cultivars ‘Maehyang’, ‘Seolhyang’, ‘Keumhyang’ (Korean short-day cultivars), ‘Akihime’, ‘Red pearl’, and ‘Sachinoka’ (Japanese short-day cultivars) were exposed to short-day (10-h photoperiods) conditions at the high elevation (HE, 800 m elevation) for 35 days beginning in late June. On 31 July, plants were removed from the SD environment and established in a substrate system at the highland. In 2009, the ‘Akihime’ and ‘Seolhyang’ were examined again. In 2008, flower bud initiation rate was above 90.0% for all cultivars except for ‘Akihime’ (83.3%). Fruit harvest commenced 1st of October 2008 and average fruit weight was consistently > 20g except for ‘Sachinoka’ (18 g). By mid-November, plants of ‘Seolhyang’ and ‘Akihime’ produced 222–260 more grams of fruit compared to other cultivars, with ‘Seolhyang’ having the earliest production. In 2009 experiment, flower bud initiation rates of ‘Akihime’ and ‘Seolhyang’ plants were 85.4% and 82.4%. Due to the earlier planting in 2009, fruit harvest commenced on 8 September (one month earlier than in 2008) and extended over 10 weeks. Yield and fruit numbers of ‘Akihime’ and ‘Seolhyang’ were 397.7 g, 22.7 and 331.7 g, 19.8, respectively. Results of this study indicate that exposure to SD photoperiods and relatively cool temperatures at HE can increase autumn fruit production in SD strawberry cultivars ‘Akihime’ and ‘Seolhyang’.

'ST-JEAN D'ORLÉANS' STRAWBERRY

St-Jean d’Orleans is a new June-bearing strawberry cultivar (Fragaria · ananassa Duch.) released by Agriculture and AgriFood Canada, Horticultural Research and Development Center, Quebec. St-Jean d’Orleans was introduced because it has large, very firm, light-red (Royal Horticultural Society color chart 43A or 44A) (Royal Horticultural Society, 1995) shiny fruit (Table 1; Fig. 1), with an excellent shelf life and resistance to leaf diseases (Khanizadeh and Cousineau, 2005). The selection was named after the village of St-Jean located on l Ile d’Orleans, where the selection was tested.

Temperature responses, flowering and fruit yield of the June-bearing strawberry cultivars Florence, Frida and Korona

The effect of night temperature on short day (SD) floral induction has been studied in three June-bearing strawberry cultivars of different geographic origin and compared with yield performance in the cool Nordic environment. At the optimum day temperature of 18 °C, the SD flowering response of the cultivars ‘Florence’ and ‘Korona’ increased significantly with increasing night temperature from 9 to 18 °C, while an optimum was reached at 15 °C in the cultivar ‘Frida’ that is selected under cool-environment conditions in Norway. Also, while saturated flowering response was obtained with 3 weeks of SD treatment at all temperatures in ‘Frida’, several plants of ‘Florence’ and ‘Korona’ failed to initiate flowers at 9 °C night temperature even with 5 weeks of SD. The effect of extended SD period was particularly pronounced in ‘Florence’. The slow SD floral induction response of ‘Florence’ was associated with a 2 week delay of anthesis in subsequent long day (LD) conditions at 21 °C. Yield performance of the same cultivars during 2 years under field conditions at Nes Hedmark and in North Norway also demonstrated that the yield potential of ‘Florence’ was not realized under the climatic conditions prevailing at these locations. In both years the yields varied significantly among the cultivars, ‘Frida’ having the highest yields followed by ‘Korona’, with ‘Florence’ far below. It is concluded that, in the Nordic environment, autumn (September) night temperatures are obviously sub-optimal for yield performance of some June-bearing strawberry cultivars, and that this effect is mediated by autumn temperature effects on flower initiation responses.

`Clé des Champs' Strawberry

`Clé des Champs' is a new June-bearing strawberry cultivar (Fragaria ×ananassa Duch.) bred for Eastern Central Canada and climates similar to Quebec conditions. `Clé des Champs' was released for pick-your-own and shipping because it has very attractive light red, glossy (Fig. 1), and firm fruit, which have an excellent shelf life compared with `Kent'.

DOUBLE-CROP SYSTEM IN OUT-OF-SEASON STRAWBERRY PRODUCTION

There are few greenhouse strawberry (Fragaria x ananassa Duch.) producers in Finland. They grow Junebearing strawberry cultivars and obtain a maximum of two crops per year, in the spring and in the fall. The aim of this study was to develop a new plant production technique to increase productivity in greenhouse strawberry production. Plants of cultivar Korona were exposed to two successive short day (SD) treatments followed by cold storage in order to obtain two successive crops during forcing. The effects of the following daylength treatments on vegetative and generative growth were studied: treatment 1: 3 weeks SD + 2 weeks LD (long day) + 3 weeks SD; treatment 2: 3 weeks SD + 4 weeks LD + 3 weeks SD; and treatment 3: 10 weeks SD. No treatment effects on vegetative growth were observed during forcing. Two distinct flower truss formation and cropping periods were observed in treatment 2 plants, but not in treatment 1 or 3. Probably the first SD treatment started crown branching and induced flowering in a main-crown and in the oldest branch-crown(s), whereas younger branch-crowns were induced during the second SD treatment, when they had reached adequate size. There were only minor differences in the numbers of flowers and berries between treatments although the number of inflorescences in treatments 2 and 3 was almost two-fold greater than in treatment 1. Total yield was highest in treatment 3 followed by treatments 2 and 1, respectively. However, the advantage of two successive SD treatments was a longer cropping period that increased berry size.

Variation in abundance and feeding impact of tarnished plant bug (Hemiptera: Miridae) for different cultivars of strawberry: role of flowering phenology and yield attributes.

The current study evaluated whether flowering phenology and yield attributes of different strawberry cultivars affect the abundance and feeding impact of tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), as well as behavioral decisions made by feeding nymphs and ovipositing adults. The distribution of emerged nymphs in cage experiments involving nine different cultivars of June-bearing strawberry cultivars suggests that females lay more eggs on plants with numerous flower receptacles, while cultivar per se did not influence their oviposition behavior. A large number of nymphs emerged from receptacles of strawberry plants, while the distribution of emerged nymphs among receptacles, petioles, leaves, and stems varied for different cultivars. These results suggest that the relative intensity of damage caused by ovipositing females may vary for different cultivars. Foraging nymphs did not exhibit a preference for any strawberry cultivar per se, although the abundance of nymphs increased with the weight of receptacles, especially for late instars. Evaluating the density and feeding impact of L. lineolaris for different cultivars under field conditions revealed that some host plant attributes affect the abundance of plant bugs, such as early flowering season and high productivity. Decreasing number of emerged nymphs per flower per plant with increasing density of receptacles per plant suggests that females lay relatively more eggs per receptacle on plants with few receptacles; this pattern of oviposition may explain, in part, why patches with low density of plants typically have high incidence of damage. Planting a high yielding early season cultivar such as 'Cavendish' may contribute to reduce the incidence of damage by L. lineolaris.

Evaluation of three methods to assess winter hardiness of strawberrygenotypes

SummaryIn northern regions, winter injury is a frequent problem in strawberry (Fragaria X ananassa Duch.) production. Controlled freezing tests provide an option for screening of winter survival potential in different genotypes. In this study, winter hardiness of strawberry genotypes was evaluated by three low-temperature procedures: an artificial hardening-dehardening-rehardening programme accompanied by freezing tests, prolonged freezing test, and laboratory cold hardiness measurements of field-grown plants. Rooted runner cuttings of five June-bearing strawberry cultivars and three new selections were tested in the course of two years. Relative winter hardiness of the genotypes could not be predicted by the hardening-dehardening-rehardening programme employed in the present study. Prolonged freezing at –6˚C yielded promising results, whereas storage at _4˚C and –8˚C failed in discrimination between genotypes. Field-grown plants were sampled for cold hardiness measurements in January, March and April. The genotypes were best differentiated in January, at a fully acclimated state. The results indicate that strawberry winter hardiness can be evaluated by testing differences in the ability to survive lengthy exposure to sub-lethal low temperatures, or by applying conventional freezing tests to measure cold hardiness in different genotypes after field acclimation.

EVALUATION OF THREE METHODS TO ASSESS WINTER-HARDINESS OF STRAWBERRY GENOTYPES

SummaryIn northern regions, winter injury is a frequent problem in strawberry (Fragaria X ananassa Duch.) production. Controlled freezing tests provide an option for screening of winter survival potential in different genotypes. In this study, winter hardiness of strawberry genotypes was evaluated by three low-temperature procedures: an artificial hardening-dehardening-rehardening programme accompanied by freezing tests, prolonged freezing test, and laboratory cold hardiness measurements of field-grown plants. Rooted runner cuttings of five June-bearing strawberry cultivars and three new selections were tested in the course of two years. Relative winter hardiness of the genotypes could not be predicted by the hardening-dehardening-rehardening programme employed in the present study. Prolonged freezing at –6˚C yielded promising results, whereas storage at _4˚C and –8˚C failed in discrimination between genotypes. Field-grown plants were sampled for cold hardiness measurements in January, March and April. Th...

Influence of photoperiod and duration of short-day treatment on vegetative growth and flowering of strawberry (Fragaria3ananassa Duch.)

SummaryIn Junebearing strawberry cultivars, flowering is induced by short photoperiod, which also reduces vegetative growth. The loss in vigour can lower yield if plants are not cold treated to restore vegetative growth. The aim of this study was to find a photoperiod treatment that induces flowering but does not reduce vegetative growth in strawberry ‘Korona’. Plants were subjected to different photoperiods (12, 13.5 or 15.h) for varying durations (21, 35 or 49.d). After treatments, effects on plant development were recorded during forcing at 18 h daylength. Floral induction was comparably successful in 12 and 13.5.h photoperiods and the number of flowers and yield were increased by lengthening the treatment. Induction failed in many plants treated in a 15.h photoperiod and flowering was poor regardless of duration of treatment. Shorter photoperiod increased the number of branch crowns and reduced runner production, and these effects were enhanced by lengthening the treatment duration. Reduction in vegetative growth measured by petiole length was most obvious in 12.h photoperiod in all treatment durations, although the differences between treatments rapidly disappeared during forcing. Twelve and 13.5.h photoperiods were equally efficient in producing yield, but more vigorous vegetative growth was maintained during treatment in a 13.5.h photoperiod.

The effects of lifting date, chilling duration and forcing temperature on vegetative growth and fruit production in the Junebearing strawberry cultivar Elsanta

SummaryThe effects of different durations of cold storage (0, 2, 4, 6, 8, 10 and 12 weeks at –2°C and +3°C) on strawberry plants cv. Elsanta from two different lifting dates (6 November and 6 December) were investigated, to determine the chilling required for optimum growth and development. With greater durations of chilling, the petiole length, leaf weight and runner production of plants were increased. The chilling requirement for optimum vegetative growth was saturated after 6–8 weeks. For chilling durations up to six weeks there was no difference between the two cold storage temperatures, but with larger durations subsequent vegetative growth of the plants stored at –2°C was reduced compared with plants stored at +3°C. The vegetative growth after cold storage of plants lifted on 6 December was greater than that of plants lifted on 6 November. Cold storage temperature did not affect the number of flowers produced per plant, fruit number or fruit weight. However fruit number and fruit weight were both greater in plants lifted on 6 November than in those lifted on 6 December. In a second experiment, the effects of chilling duration on growth and fruiting at three forcing temperatures were studied. There was no significant interaction between chilling duration and temperature during forcing, and while eight weeks chilling was optimum for vegetative growth, in terms of fruit production four weeks chilling was optimum. Overall, these results indicate that there may be an important interaction between fruit set and vegetative vigour and that field chilling is more effective than cold store chilling in promoting vegetative growth. The results also show that the optimum chilling requirements for vegetative vigour and fruit production are different, and that chilling becomes more important when the temperature during forcing is low.

`OKA' STRAWBERRY

`Oka' is a mid-season, high yielding June-bearing strawberry cultivar with excellent productivity, good fruit color, flavor and firmness. It is recommended for fesh market and pick your own for the Southern Québec region. `Oka' plants are of medium size, and vigor with five to seven inflorescences per mother plant. They can tolerate winter temperatures of -25 C. Inflorescences are held erect on medium to long peduncles during bloom, and become semi-erect as fruit mature. Fruits are large, wedge shape and the calyces are semi-reflexed. Skin is moderately shiny, light red at full maturity, and the flesh is light red. Fruit flavor is similar to `Bounty', `Chambly', `Glooscap' and `Sparkle'. Fruits are medium firm to firm, and can not be decapped as easily as `Bounty', `Chambly' or `Glooscap'. More than 50% of harvested fruit have long pedicels. Percent juice loss after thawing does not differ significantly from other popular cultivars. `Oka' has outyielded `Bounty', `Redcoat' and `Sparkle' at L'Acadie and `Bounty', `Glooscap', and `Veestar' in New Brunswick. Plants can tolerate the herbicide terbacil. No symptoms of powdery mildew or leaf scorch were observed during the course of its evaluation. However some symptoms of leaf spot were observed late in the season before the onset of dormancy. Preliminary studies show that `Oka' is resistant to races 2, 4, 5, 8, 9 and 10 of P. fragariae.