Bare-root Plants Research Articles

Manipulating Propagule Type and Interrow Ground Cover to Influence Flowering Time, Yield, Fruit Quality, and Harvest Dates in the Day-neutral Strawberry ‘Albion’

We examined methods of producing day-neutral strawberries in a north temperate climate using alternatives to standard bare-root propagules and clean cultivation between plant rows. Fragaria ×ananassa ‘Albion’ were planted in plastic-covered raised beds in Ithaca, NY, USA, for each of the 2022 and 2023 growing seasons. Plants were selected from the following four propagule types from different developmental stages: standard bare-root plants set in early May; bare-root plants started in the greenhouse in February and planted in early May; bare-root plants started in the greenhouse in March and planted in early May; and plug plants set in the field in fall (Aug 2021 and Oct 2022) of the previous year. To determine if pollination could be enhanced, each type of plant was grown in plots in the field with one of the following between rows: bare ground; a diverse flowering groundcover; or exclusion netting on hoops over the strawberry plants when they were flowering. Pollinators visiting strawberries were observed weekly and identified to species when possible. Fruits were collected weekly and marketable and unmarketable yields were measured through the harvest season. Fall-planted plugs produced significantly higher marketable yields than those of other propagule types in both years. Bare-root plants set in early May had the lowest yield. Percent marketable yield varied depending on the growing year because of drastically different weather conditions. There was no evidence that flowering groundcover attracted pollinators to the strawberry plants because strawberries had few pollinator visits, regardless of the surrounding vegetation. Exclusion netting had significantly higher percent marketable yield and total yield than the those of other groundcover types despite lower percent fruit set, likely because of the benefits of tarnished plant bug exclusion.

Potassium Sulfate Supplementation with Elevated Electrical Conductivity Was Unproductive for Hydroponic Strawberry at the Original Yamazaki Nutrient Solution Nitrogen Level

The production of strawberries (Fragaria ×ananassa) in hydroponic systems has been increasing. In hydroponic systems, precise nutrient management is crucial for optimal plant growth and fruit production. Among essential elements, potassium (K) is a key nutrient that affects fruit yield and quality in fruiting crops. The objective of this study was to investigate whether increasing the K concentration in the Yamazaki strawberry nutrient solution could enhance plant growth, fruit yield, and fruit quality in hydroponic strawberries. Bare-root plants of strawberry ‘Monterey’ and ‘San Andreas’ were planted in a deep water culture hydroponic system and grown with initial K concentrations of 117, 194, 271, and 348 mg·L−1 under the same initial nitrogen concentration of 77 mg·L−1. As the K concentration increased from 117 to 348 mg·L−1, the nutrient solution electrical conductivity increased from 1.0 to 1.9 dS·m−1. The experiment was conducted inside an indoor vertical farm at a 23 °C air temperature with an extended photon flux density (400–750 nm) of 350 µmol·m−2·s−1 under an 18-hour photoperiod. Increasing the K concentration from 117 to 348 mg·L−1 had minimal effects on plant growth characteristics of both cultivars, although root dry mass of ‘Monterey’ increased linearly with increasing K. Increasing the K concentration from 117 to 348 mg·L−1 did not affect the total fruit number or total fruit fresh mass of ‘Monterey’, but for ‘San Andreas’, it reduced the total fruit number by 34% and total fruit fresh mass by 45%. Additionally, increasing the K concentration from 117 to 348 mg·L−1 reduced the individual fruit mass, fruit length, and fruit diameter and increased titratable acidity in both cultivars. These results indicate that increasing the K concentration in the Yamazaki strawberry nutrient solution did not benefit plant growth, fruit yield, or fruit quality of the hydroponically grown strawberries ‘Monterey’ or ‘San Andreas’.

Commodity risk assessment of Alnus cordata, Alnus glutinosa and Alnus incana plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'high-risk plants, plant products and other objects'. Taking into account the available scientific information, including the technical information provided by the applicant country, this Scientific Opinion covers the plant health risks posed by the following commodities: Alnus cordata, A. glutinosa and A. incana graftwood, bare-root plants and rooted plants in pots up to 7 years old imported into the EU from the UK. A list of pests potentially associated with the commodities was compiled. The relevance of each pest was assessed based on evidence following defined criteria. Two EU-quarantine pests (Entoleuca mammata, Phytophthora ramorum (non-EU isolates)) and one non-quarantine pest (Phytophthora siskiyouensis) were selected for further evaluation. For the selected pests, the risk mitigation measures implemented in the UK and specified in the technical dossier were evaluated taking into account the factors reducing their efficacy. For these pests, an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The degree of pest freedom varies between the pests evaluated, with E. mammata being the pest most frequently expected on imported Alnus spp. small trees. Expert knowledge elicitation indicated, with 95% certainty, that between 9927 and 10,000 per 10,000 Alnus spp. small trees (bare-root plants or rooted plants in pots up to 7 years old) would be free from E. mammata.

Commodity risk assessment of Betula pendula and Betula pubescens plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of Betula pendula and B. pubescens imported from the United Kingdom (UK) taking into account the available scientific information, including the technical information provided by the UK. The commodities were grouped in the risk assessment as (a) bundles of 10-20 graftwood/budwood (up to 1-year-old), (b) bare root plants which include bundles of 25 or 50 seedlings or transplants (1-2 years-old), bundles of 5, 10 or 15 whips (1-2 years-old) and single bare root plants (1-7 years-old), (c) plants in pots which include bundles of 5 and 10 cell-grown plants (1-2 years-old) and rooted plants in pots (1-7 years-old), and (d) large specimen trees up to 15-years-old. All pests associated with the commodities were evaluated against specific criteria for their relevance for this opinion. Two EU quarantine pests i.e. Meloidogyne fallax and Phytophthora ramorum (non-EU isolates) and two protected zone quarantine pests i.e. Entoleuca mammata and Thaumetopoea processionea fulfilled all relevant criteria and were selected for further evaluation. For the selected pests, the risk mitigation measures described in the technical dossier from the UK were evaluated considering the possible limiting factors. For these pests an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. In the assessment of risk, the age of the plants was considered, as larger trees are more likely to be infested mainly due to longer time grown in the field. In addition, larger canopies and root systems are more difficult to inspect, thereby making the detection of pests more challenging on large trees. The likelihood of pest freedom varies among the pests evaluated, with M. fallax being the pest most frequently expected on the imported plants. The Expert Knowledge Elicitation (EKE) indicated with 95% certainty that between 9735 and 10,000 per 10,000 large specimen trees will be free from M. fallax.

First Report of Neopestalotiopsis spp. Causing Leaf Spot and Petiole Blight on Strawberry in New England.

In October 2023, a Connecticut grower contacted The Connecticut Agricultural Experiment Station about a field of strawberry plants (Fragaria × ananassa) (cv. Ruby June) showing symptoms of severe leaf spotting and visual wilting. Upon visiting the field, leaves had lesions with a diffuse black halo and a light brown center and wilting symptoms, which appeared driven by petiole lesions and presented as dark brown stripes with a reddish-purple halo. Symptoms were observed on 80 to 90% of plants within the block, nearly all of which (>90%) presented with both leaf spots and severe wilting. Diseased tissue was collected from 20 leaves and 25 petioles, sterilized in 0.6% NaOCL, and plated on potato dextrose agar. After hyphal tipping a morphologically identical fungus was isolated from 70% of leaves and 88% of petioles, which formed a dense white mycelial mat with moderate aerial mycelium and conidiomata that exuded dark brown conidial masses. The underside of the mycelial mat was yellowish. Conidia were fusoid, ellipsoid, straight to slightly curved, 4-septate with a single basal appendage and 2-5 apical, matching the description of species within the genus Neopestalotiopsis (Maharachchikumbura et al. 2014). The average conidia (n=74) length, not including appendages, was 29.9 ± 2.1 µm and the average width, at the widest point, was 7.5 ± 0.7 µm. Aerial hyphae were collected from two isolates, CT58-1 and CT62-2, and DNA was extracted for further molecular characterization. PCR was performed with primers targeting actin (ACT), β-tubulin (TUB2), and ITS prior to amplicon sequencing (Carbone and Kohn 1999; Hassan et al. 2018). Sequences were queried against the NCBI whole genome shotgun database, and aligned sequences from 13 species (including Neopestalotiopsis, Pestalotiopsis, and Pseudopestalotiopsis) were collected for each locus. Sequences were aligned, trimmed, and concatenated using Mega11, and IQ-TREE was employed for model selection (Nguyen et al. 2015; Tamura et al. 2021). A maximum-likelihood tree placed the isolates in a high-confidence cluster with Neopestalotiopsis rosae, confirming this placement of these isolates within the genus (CT58-1 Accession #: PP715979-89; PP707735). To confirm pathogenicity, CT58-1 was grown on autoclaved strawberry leaves to induce sporulation, and a suspension of 105 spores/ml was made. Five milliliters of this spore suspension was sprayed on six 6-week-old strawberries (cv. Jewel), and water was sprayed on the same number of control plants. Plants were at 100% humidity for two days and then kept in the greenhouse for 3 weeks to observe symptoms. Inoculated plants presented with identical leaf spot and petiole lesions to field samples and no visual symptoms were observed on control plants. New isolations were made from infected petioles, which produced morphologically identical spores to those described above, and ITS/ACT loci sequencing yielded sequences identical to those of CT58-1. Spore production and plant inoculations were repeated with this new isolate, and identical symptoms were observed. This is the first report of Neopestalotiopsis infecting strawberries in New England and given the high disease incidence in the initial infected field and relative lack of disease in a neighboring field, it is likely that this pathogen was introduced on bare root plants. As the plants were sourced from a nursery in Ontario, Canada, it is likely that the pathogen is capable of overwintering in the Northeastern United States.

Commodity risk assessment of Prunus spinosa plants from United Kingdom.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by potted plants and bundles of bare-root plants or cell grown young plants or graftwood/budwood of Prunus spinosa imported from the United Kingdom, taking into account the available scientific information, including the technical information provided by the UK. All pests associated with the commodities were evaluated against specific criteria for their relevance for this opinion. One quarantine pest, Scirtothrips dorsalis, one protected zone quarantine pest Bemisia tabaci (European population) and one non-regulated pest, the scale Eulecanium excrescens, that fulfilled all relevant criteria were selected for further evaluation. The risk mitigation measures proposed in the technical Dossier from the UK were evaluated, taking into account the possible limiting factors. For these pests, expert judgement is given on the likelihood of pest freedom, taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The degree of pest freedom varies among the pests evaluated, with E. excrescens being the pest most frequently expected on the imported potted plants. The Expert Knowledge Elicitation indicated with 95% certainty that between 9981 and 10,000 plants per 10,000 would be free from the above-mentioned scale.

Novel Low Tunnel Coverings and Plant Type Affect Productivity of Day-neutral Strawberries

Growers producing day-neutral strawberries (Fragaria ×ananassa) in temperate climates face challenges when attempting to extend the season and mitigate the effects of rain. Conventional plastic coverings over low tunnels have been used for these purposes, but they often exacerbate heat-induced problems in summer. We examined two approaches for addressing this challenge. The first was to start dormant bare root ‘Albion’ strawberry plants in small pots in the greenhouse, then plant them into the field in spring so they could begin production before the onset of consistently high temperatures. Plants set in small pots on 26 Feb in the greenhouse and field planted on 6 May were compared with bare root plants set directly into the field on 6 May. The second approach used various low tunnel coverings to modify the light and temperature environment around the plants. Three coverings were woven nets embedded with reflective strips at various densities that allowed 50%, 60%, and 70% light transmission, and these were intended to lower temperatures under the covers by reflecting infrared radiation. A fourth covering was a polyethylene plastic embedded with optically active additives that shift incident light into wavelengths that are more photosynthetically active. Two other covers were standard commercial polyethylene plastics, and the final treatment was an uncovered control. Over the 2020 and 2021 growing seasons (hot and dry vs. moderate and wet, respectively), plots were harvested once or twice a week from June through October and fruit yield, size, and marketability were assessed. In both years, strawberry plants started in the greenhouse produced significantly higher yields than bare root plants over the season (30.5% and 43.7%). Bare root plants were less responsive to cover type than greenhouse plants. In 2020, yields tended to be higher in the middle of summer in plots with reflective coverings that reduced temperature and higher later in the season with coverings of wavelength-shifting film. Polyethylene covers that increased temperature without shifting the light spectrum had lower yields. Under the cooler conditions of 2021, plants under covers that increased temperature tended to have higher yields. In a third year (2023), bare root plants were covered with a reflective covering from 29 Jun until 1 Sep, then this cover was replaced with polyethylene with optical additives as the weather cooled and light levels dropped. This sequenced treatment was compared with uncovered plots and plots covered with standard commercial polyethylene plastic. Plants under the two-phase sequential covering performed significantly better than uncovered plots or those covered with standard polyethylene plastic alone.

Commodity risk assessment of Sorbus aucuparia plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'high risk plants, plant products and other objects'. Taking into account the available scientific information, including the technical information provided by the applicant country, this Scientific Opinion covers the plant health risks posed by the following commodities: Sorbus aucuparia bare-root plants and rooted plants in pots up to 7 years old and specimen trees in pots up to 15 years old imported into the EU from the UK. A list of pests potentially associated with the commodities was compiled. The relevance of any pest was assessed based on evidence following defined criteria. Three EU quarantine pests (Entoleuca mammata and Phytophthora ramorum (non-EU isolates), Erwinia amylovora), were selected for further evaluation. For two of the selected pests (E. mammata and P. ramorum), the risk mitigation measures implemented in the UK and specified in the technical dossier were evaluated taking into account the possible limiting factors. For these pests, an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The degree of pest freedom varies between the pests evaluated, with P. ramorum being the pest most frequently expected on the imported S. aucuparia plants. The Expert Knowledge Elicitation indicated, with 95% certainty, that between 9812 and 10,000 bare-root S. aucuparia plants per 10,000 will be free from P. ramorum.

Commodity risk assessment of Ligustrum ovalifolium and Ligustrum vulgare plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of the evergreen Ligustrum ovalifolium and the semi-evergreen Ligustrum vulgare imported from the United Kingdom (UK) as: (a) bare root plants and (b) plants in pots, taking into account the available scientific information, including the technical information provided by the UK. The category (a) 'bare root plants' includes bundles of 1- to 3-year-old bare root whips or transplants and single 1- to 7-year-old bare root plants. The category (b) 'plants in pots' includes bundles of 1- to 2-year-old cell grown plants (only L. vulgare) and 1- to 5-year-old plants in pots. All pests associated with the commodities were evaluated against specific criteria for their relevance for this opinion. Two EU quarantine pests, Bemisia tabaci and Scirtothrips dorsalis, and one pest not regulated in the EU, Diaprepes abbreviatus, fulfilled all relevant criteria and were selected for further evaluation. For the selected pests, the risk mitigation measures proposed in the technical dossier from the UK were evaluated taking into account the possible limiting factors. For these pests, an expert judgement is given on the likelihood of pest freedom considering the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. In the assessment of risk, the age of the plants was considered, reasoning that older trees are more likely to be infested mainly due to longer exposure time and larger size. The degree of pest freedom varies among the pests evaluated, with B. tabaci being the pest most frequently expected on the imported plants. The Expert Knowledge Elicitation indicated with 95% certainty that between 9915 and 10,000 per 10,000 bare root plants and plants in pots will be free from B. tabaci.

Commodity risk assessment of plants of 12 selected Prunus species from Moldova.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High-risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by defoliated 1- or 2-year old bare root plants for planting (grafted or not) of 12 Prunus species (Prunus armeniaca, P. avium, P. canescens, P. cerasifera, P. cerasus, P. davidiana, P. domestica, P. dulcis, P. fontanesiana, P. persica, P. salicina, P. tomentosa) imported from Moldova, taking into account the available scientific information, including the technical information provided by the applicant country. The evaluation identified three EU-quarantine pests, Erwinia amylovora (protected zone quarantine pest), Xiphinema rivesi non-EU populations and Xanthomonas arboricola pv. pruni (protected zone quarantine pest), which were selected for further evaluation, based on defined criteria, including their presence in the applicant country. It should be noted that there is uncertainty regarding whether all relevant pests have been identified due to a limited number of scientific publications and pest surveys in Moldova. For the three selected pests, the risk mitigation measures proposed in the technical dossier from Moldova were evaluated taking into account the possible limiting factors. For these pests, an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on it, including uncertainties associated with the assessment. The degree of pest freedom varies among the pests evaluated, with Erwinia amylovora being the pest most frequently expected on the imported plants. The Expert Knowledge Elicitation indicated, with 95% certainty, that between 9823 and 10,000 bundles (comprising 10-20 plants per bundle) out of 10,000 bundles would be free from E. amylovora.

Commodity risk assessment of Cornus alba and Cornus sanguinea plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'high risk plants, plant products and other objects'. Taking into account the available scientific information, including the technical information provided by the applicant country, this Scientific Opinion covers the plant health risks posed by the following commodities: Cornus alba and Cornus sanguinea bare-root plants and rooted plants in pots up to 7 years old imported into the EU from the UK. A list of pests potentially associated with the commodities was compiled. The relevance of any pest was assessed based on evidence following defined criteria. Four EU quarantine pests (Meloidogyne fallax, Phytophthora ramorum (non-EU isolates), tobacco ringspot virus, and tomato ringspot virus) and one EU non-regulated pest (Discula destructiva), were selected for further evaluation. For the selected pests, the risk mitigation measures implemented in the technical dossier from the UK were evaluated taking into account the possible limiting factors. For these pests, an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The degree of pest freedom varies among the pests evaluated, with P. ramorum being the pest most frequently expected on the imported C. alba and C. sanguinea plants. The Expert Knowledge Elicitation indicated, with 95% certainty, that between 9823 and 10,000 bare-root C. alba and C. sanguinea plants per 10,000 will be free from P. ramorum.

Rice hull-based substrates and the influence of the type of transplant and the age of the plant on the strawberry culture

The soilless growing of strawberries using local materials as a substrate is an alternative to reduce costs and reuse waste. The objective of this work was to evaluate the growth and yield of strawberry plants cultivar Aromas, originated from bare root and plug plants, as well as second-year plants in comparison to first-year plants, in substrates formulated with raw rice husk (RRH) and two types of conditioners [carbonized rice husk (CRH) and commercial substrate (S10)]. The experimental factors consisted of four substrates [RRH (100%), RRH + CRH (80 %: 20 %), RRH + S10 (80 %: 20 %), and RRH + CRH + S10 (80 %:10 %:10 %)], two types of transplants (plug plants and bare-root), and the maintenance of second-year plants in comparison to first-year plants. For the first year of growing, regardless of the substrate, plug plants showed greater growth and yield, providing an increase of 62.1 % in the commercial yield of plug plants in relation to the growing of bare-root transplants. As for the growing of bare-root transplants, the addition of CRH and its simultaneous use with commercial substrate S10 as RRH conditioners increased plant growth. However, fruit yield gains were less expressive and clear positive responses for this variable were obtained only with the simultaneous use of CRH and the commercial substrate S10. The results obtained in the second experiment indicate that second-year plants, on mean, showed greater vegetative growth, number and yield of fruits, however, with lower mean weight of fruits than the plants of the first year. First year plants showed superior commercial yield in the RRH + S10 substrate.

Commodity risk assessment of Malus domestica plants from Bosnia and Herzegovina.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High-risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by bare root plants of Malus domestica grafted on rootstocks of either Malus domestica or Malus sylvestris imported from Bosnia and Herzegovina (BIH), taking into account the available scientific information, including the technical information provided by Bosnia and Herzegovina. All pests associated with the commodities were evaluated against specific criteria for their relevance for this opinion. One protected zone quarantine pest, Erwinia amylovora, fulfilled all relevant criteria and was selected for further evaluation. For E. amylovora, special requirements are specified in Commission Implementing Regulation (EU) 2019/2072. Based on the information provided in the Dossier, these specific requirements for E. amylovora are not met.

Commodity risk assessment of Quercus robur plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High-risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of Quercus robur imported from the UK as: (a) bundles of 1- to 2-year-old whips and seedlings, (b) 1- to 7-year-old bare root plants for planting and (c) less than 1- to 15-year-old plants in pots, taking into account the available scientific information, including the technical information provided by the UK. All pests associated with the commodity were evaluated against specific criteria for their relevance for this opinion. Two EU quarantine pests, Cronartium quercuum and Phytophthora ramorum (non-EU isolates), two protected zone quarantine pests, Cryphonectria parasitica and Thaumetopoea processionea and four pests not regulated in the EU, Coniella castaneicola, Meloidogyne mali, Phytophthora kernoviae and Trinophylum cribratum, fulfilled all relevant criteria and were selected for further evaluation. For the selected pests, the risk mitigation measures included in the technical dossier from the UK were evaluated taking into account the possible limiting factors. For these pests an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. In the assessment of risk, the age of the plants was considered, reasoning that older trees are more likely to be infested mainly due to longer exposure time and larger size. The degree of pest freedom varies among the pests evaluated, with C. castaneicola being the pest most frequently expected on the imported plants. The expert knowledge elicitation indicated with 95% certainty that between 9,711 and 10,000 per 10,000 less than 1- to 15-year-old plants in pots will be free from C. castaneicola.

Efficiency of Strawberry Cultivation under the Effect of Different Types of Plants in a Soilless System in the High-Altitude Regions of Southern Brazil

By analyzing the growth and development of different types of strawberry plants, the researchers were able to evaluate the interference with the horticultural potential of the cultivar ‘Albion’. The five treatments that have been studied corresponded to different types of strawberry plants: mini plants in trays with young roots, plants in trays with mature roots and an initial reduction of fertigation, plants in trays with mature roots, plants with bare roots, and plants in trays with mature roots preserved by the cold. In bags containing coconut fiber, the experiment was laid out in a randomized block design with three replications. The attributes evaluated were the total yield per plant, the total yield per plant with fruits above 10 g, the total yield per hectare, the total yield per hectare with fruits above 10 g, the average plant diameter, the average number of buds per plant, and the average number of stolons per plant. There were no significant effects among the plant types concerning yield production. Plants in cold-preserved trays with mature roots showed a higher number of buds than plants in trays with mature roots. Cold-preserved tray plants with mature roots produced the highest number of stolons, followed by bare-root plants. It is concluded that the types of strawberry seedlings did not influence the productive performance of the strawberry ‘Albion’ cultivar. However, cold-preserved tray plants with mature roots showed better vegetative performance, with a yield of a higher number of buds and stolons. However, the results were influenced by the agroclimatic conditions of the producing region; due to climatic interference in the behaviour of the plants about the factors studied, it is recommended to repeat the experiment for a better understanding of the objectives.

Commodity risk assessment of Acer palmatum plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of Acer palmatum imported from the United Kingdom (UK) as: (a) 1- to 2-year-old bare root plants for planting and (b) 1- to 7-year-old plants in pots, taking into account the available scientific information, including the technical information provided by the UK. All pests associated with the commodity were evaluated against specific criteria for their relevance for this opinion. Six EU quarantine pests and four pests not regulated in the EU fulfilled all relevant criteria and were selected for further evaluation. For these pests, the risk mitigation measures implemented in the technical dossier from the UK were evaluated taking into account the possible limiting factors. For the selected pests an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The degree of pest freedom varies among the pests evaluated, with Meloidogyne mali or M. fallax being the pest most frequently expected on the imported plants. The expert knowledge elicitation indicated with 95% certainty that 9,792 or more plants in pots per 10,000 will be free from Meloidogyne mali or M. fallax.

Commodity risk assessment of Fagus sylvatica plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of Fagus sylvatica imported from the United Kingdom (UK) as: (a) 1- to 7-year-old bare root plants for planting, (b) < 1- to 15-year-old plants in pots and (c) bundles of 1- to 2-year-old whips and seedlings, taking into account the available scientific information, including the technical information provided by the UK. All pests associated with the commodity were evaluated against specific criteria for their relevance for this opinion. Two EU quarantine pests, Phytophthora ramorum (non-EU isolates) and Thaumetopoea processionea, and two pests not regulated in the EU, Meloidogyne mali and Phytophthora kernoviae, fulfilled all relevant criteria and were selected for further evaluation. For the selected pests, the risk mitigation measures implemented in the technical dossier from the UK were evaluated taking into account the possible limiting factors. For these pests an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. In the assessment of risk, the age of the plants was considered, reasoning that older trees are more likely to be infested mainly due to longer exposure time and larger size. The degree of pest freedom varies among the pests evaluated, with M. mali being the pest most frequently expected on the imported plants. The expert knowledge elicitation (EKE) indicated with 95% certainty that between 9,793 and 10,000 plants in pots up to 15 years old per 10,000 will be free from M. mali.

Commodity risk assessment of Malus sylvestris plants from United Kingdom

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by rooted plants and bundles of bare root plants or rooted cell grown young plants of Malus sylvestris imported from the UK, taking into account the available scientific information, including the technical information provided by the UK. All pests associated with the commodities were evaluated against specific criteria for their relevance for this opinion. Two quarantine pests (tobacco ringspot virus and tomato ringspot virus), one protected zone quarantine pest (Erwinia amylovora) and four non-regulated pests (Colletotrichum aenigma, Meloidogyne mali, Eulecanium excrescens and Takahashia japonica) that fulfilled all relevant criteria were selected for further evaluation. For Erwinia amylovora, special requirements are specified in Commission Implementing Regulation (EU) 2019/2072. Based on the information provided in the dossier, these specific requirements for E. amylovora are met. For the remaining six pests, the risk mitigation measures proposed in the technical Dossier from the UK were evaluated, taking into account the possible limiting factors. For these pests, expert judgement is given on the likelihood of pest freedom, taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The degree of pest freedom varies among the pests evaluated, with scales (Eulecanium excrescens and Takahashia japonica) being the pests most frequently expected on the imported bundles of bare root plants or rooted cell grown young plants. The expert knowledge elicitation indicated with 95% certainty that between 9,976 and 10,000 bundles (one bundle consisting of 5-15 plants for bare root plants or 25-50 plants for cell grown young plants) per 10,000 would be free from the above-mentioned scales.

Commodity risk assessment of Malus domestica plants from United Kingdom.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by rooted plants in pots, bundles of bare-rooted plants or trees and bundles of budwood and graftwood of Malus domestica imported from the United Kingdom, taking into account the available scientific information, including the technical information provided by the United Kingdom. All pests associated with the commodities were evaluated against specific criteria for their relevance for this opinion. Two quarantine pests (tobacco ringspot virus and tomato ringspot virus), one protected zone quarantine pest (Erwinia amylovora) and four non-regulated pests (Colletotrichum aenigma, Meloidogyne mali, Eulecanium excrescens, Takahashia japonica) that fulfilled all relevant criteria were selected for further evaluation. For E. amylovora, special requirements are specified in Commission Implementing Regulation (EU) 2019/2072. Based on the information provided in the Dossier, the specific requirements for E. amylovora were met. For the remaining six pests, the risk mitigation measures proposed in the technical Dossier from the UK were evaluated considering the possible limiting factors. For the selected pests, expert judgement is given on the likelihood of pest freedom, taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The degree of pest freedom varies among the pests evaluated, with scales (E. excrescens and T. japonica) being the pests most frequently expected on the imported budwood and graftwood. The Expert Knowledge Elicitation indicated with 95% certainty that between 9,976 and 10,000 bundles (consisting of 50 up to 500 plants each) per 10,000 would be free from the above-mentioned scales.

Commodity risk assessment of Crataegus monogyna plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. Taking into account the available scientific information, including the technical information provided by the applicant country, this Scientific Opinion covers the plant health risks posed by the following commodities: Crataegus monogyna bare root plants and rooted plants in pots imported into the EU from the UK. A list of pests potentially associated with the commodities was compiled. The relevance of any pest was assessed based on evidence following defined criteria. Only the quarantine pest Erwinia amylovora was selected for further evaluation. For E. amylovora the special requirements specified in the Commission Implementing Regulation (EU) 2019/2072 are fulfilled by the UK and no other pests for further evaluation were selected.