Don Seedlings Research Articles

Use of sewage sludge in the production and quality of Jacaranda mimosifolia D. Don seedlings

Use of sewage sludge in the production and quality of Jacaranda mimosifolia D. Don seedlings

Decomposed Babassu Biomass: New Substrate for the Production of Jacaranda mimosifolia D. Don Seedlings

In Maranhão babassu forest, the decomposed babassu biomass (DBB) has been used empirically by several farmers for the production of Jacaranda mimosifolia seedlings. This study aimed to evaluate the potential of DBB as a substrate. The substrate compositions were S1: 100% soil (control); S2: 20% DBB; S3: 40% DBB; S4: 60% DBB; S5: 80% DBB and S6: 100% DBB. The experiment was carried out from October to December 2019 at Federal University of Maranhão, Chapadinha, Maranhão, Brazil. It was observed the use of DBB enhances the emergency speed index and germination percentage, besides resulted in the development of the aerial part and the root development. Thus, DBB may be used as an alternative substrate for the production of Jacaranda mimosifolia seedlings. It is recommended to include 40% babassu biomass with 60% soil in the composition of the substrate to improve the morphological development of Jacaranda mimosifolia seedlings.

Reduced fungicide use in the nursery improves post-planting productivity of Pinus radiata for at least six years

The fertilisers and fungicides used in tree nurseries to stimulate growth and provide disease protection are an important component of conventional nursery management. However, it has been demonstrated that the ectomycorrhizal (ECM) fungi associating with Pinus radiata D. Don seedlings in the nursery can be significantly affected by increasing exposure to these products, driving reductions in the relative proportion of the ECM species most positively correlated with seedling nutrient uptake. Increasing fungicide exposure was also shown to reduce seedling size. To determine the significance of these effects on post-nursery performance, 2592 P. radiata seedlings were randomly selected from within treatment plots in this nursery chemical exposure trial and established at a site in Kaingaroa Forest, New Zealand. Assessments of the ECM community present on the trees in the plantation determined that after two years there was no longer any effect of the nursery treatments, likely due to the homogenising effect of the site conditions. Over six years the performance of the trees in the plantation was not affected by the extent of fertiliser application during their time in the nursery, but decreased nursery fungicide use had slight positive legacy effects on both tree survival and diameter growth. These gains combined to produce a significant increase in plot level basal area with reduced nursery fungicide use. Further analysis incorporating the effect of thinning on stand dynamics reinforced the potential gains in the forest from reduced fungicide use in the nursery, and the lack of benefit from fertiliser use. Based on the data collected following trial establishment, it was concluded that the observed differences in tree performance were likely driven by the impact of the ECM communities initially associated with the seedlings at planting. While the authors strongly recommend any reductions in P. radiata nursery fungicide use be considered carefully due to ongoing issues with fungal pathogens in these monoculture systems, the potential for improved nursery and plantation performance is significant and should be explored more widely.

Tropospheric ozone and cadmium do not have interactive effects on growth, photosynthesis and mineral nutrients of Catalpa ovata seedlings in the urban areas of Northeast China

Heavy metal contamination and tropospheric ozone (O3) pollution often co-occur in heavy industrial urban areas, adversely affecting urban plant health. Little is known about the characteristics of growth, physiological metabolism, bioaccumulation of cadmium (Cd) and mineral nutrients in urban trees under the combination of soil Cd contamination and elevated O3 exposure. In this study, one-year-old street tree Catalpa ovata G. Don seedlings were exposed to Cd contaminated soil (0, 100, 500 mg/kg soil) with 40 µg/m3 O3 (ambient air) and 120 µg/m3 O3 (elevated O3 exposure) for 4 weeks. The results revealed that 500 mg/kg soil Cd addition alone decreased net photosynthetic rate, stomatal conductance, peroxidase activity and increased abscisic acid content and oxidative injury in the leaves of C. ovata. Furthermore, Cd soil contamination decreased leaf, stem, root and total biomass and affected Cd, Mg, Fe, and Zn contents in leaves (P < 0.01), but it did not affect Mg, Fe and Zn contents in roots. O3 exposure did not affect growth, net photosynthetic rate, Cd accumulation and mineral nutrient contents of C. ovata. No interactive effect between Cd and O3 was found on growth, oxidative injury, photosynthetic rate, and the contents of Cd, Mg, Fe and Zn in plant tissues (P > 0.05). Our findings suggest that C. ovata is an appropriate tree species for urban greening and afforestation in heavy industrial urban areas with high O3 pollution in Northeast China. To ensure successful afforestation in heavy industrial areas, the long-term and large scale studies are needed to advance our understanding of the combined effects from extreme climate conditions and multi-pollutant exposure on the metabolism of mature urban trees.

A consortium of fungal isolates and biochar improved the phytoremediation potential of Jacaranda mimosifolia D. Don and reduced copper, manganese, and zinc leaching

A consortium of fungal isolates may improve phytoremediation by stimulating root growth whereas biochar reduces metal leaching in contaminated soils. We combined these treatments to evaluate to what extent Jacaranda mimosifolia D. Don seedlings extract metals (Cu, Mn, and Zn) and reduce leaching in soil columns. Contamination treatments were established by combining Cu (200 mg dm−3), Mn (450 mg dm−3), and Zn (450 mg dm−3). A spore suspension of five fungal isolates (Beauveria bassiana, Metarhizium anisopliae, Pochonia chlamydosporia, Purpureocillium lilacinum, and Trichoderma asperella) was sprayed on plant shoots and the soil surface. Biochar (1% m/v) was produced by the pyrolysis of wood sawdust and applied to the soil surface. Finally, control treatments were established in a completely randomized block design. The consortium of fungal isolates increased shoot and root mass, improved the translocation potential of Cu (translocation factor (TF) of 0.25), Mn (TF of 2.93), and Zn (TF of 1.79) from roots to shoots, and increased the total accumulated mass of Mn and Zn in shoots and roots. Biochar applications improved Cu, Mn, and Zn translocation and increased the total accumulated mass of shoot Mn. Moreover, a combination of fungal isolates and biochar increased the translocation factor to 0.44 for Cu, 1.70 for Mn, and 1.34 for Zn relative to the treatment with J. mimosifolia in contaminated soil (CJ); increased shoot Cu concentration; and reduced total leached Cu by a factor of 22.9, Mn by 5.5, and Zn by 22.9 relative to the CJ treatment. A photochemical profile, based on chlorophyll a fluorescence, showed that Jacaranda mimosifolia was tolerant to contaminated soil and is a potential phytoremediator of Cu, Mn, and Zn. Overall, the consortium of fungal isolates and biochar improved the efficiency of phytoremediation by concentrating metals in plant tissue and reducing the risks of leaching.

Cytogenetic Abnormalities in Seed Progenies of Pinus Pallasiana D. Don Stands from Technogenic Polluted Lands in the Steppe of Ukraine

Abstract In this study, we compare the pathological mitosis rates, chromosomal abnormalities and nucleolar organizer activity in Pinus pallasiana D. Don seedlings from natural population in the Crimean Mountains and from the urban plantations in the steppe of Ukraine. On the stages of anaphase and telophase of mitosis, such chromosomal abnormalities as bridges were most often found in the seeds of plantations exposed to air pollutants, whereas lead and agglutination of chromosomes were found in seeds from iron ore dump stands. Our studies have shown that P. pallasiana can be used for genotoxic monitoring of technogenic polluted lands.

Regulating Growth of Betula alnoides Buch. Ham. ex D. Don Seedlings with Combined Application of Paclobutrazol and Gibberellin

The rainy seasons have been becoming irregular and unpredictable under global warming now. This usually makes seedling preparation more difficult to match transplanting. Here applications of plant growth regulators, paclobutrazol (PBZ) and gibberellins (GA3) were studied with two trials to regulate growth of Betula alnoides Buch. Ham. ex D. Don container seedlings for the purpose of improving their quality when transplanting delayed. In the first trial five treatments (coded as P1 to P5) were laid out with total dosages of 0 mg (control), 2 mg, 6 mg, 10 mg and 20 mg PBZ per seedling to assess inhibitory effects of PBZ on growth of B. alnoides seedlings. After four and a half months, the second trial was carried out on the seedlings from the optimized PBZ treatments to detect growth recover of the seedlings by GA3, in which four treatments were arranged with GA3 dosages being 0, 1/10, 1/5 and 1/3 of the optimized paclobutrazol amounts applied. PBZ applications resulted in a significant decrease of height and root collar diameter growth since approximately one and two months after being treated, respectively. Among these treatments, P5 was the best one in controlling seedling growth, and its inhibitory effects lasted more than four and half months. PBZ treatments differed obviously in total seedling biomass from the control at 96 and 132 days after treatment (dat), and allocated more ratio of biomass into roots. Their root/shoot ratios increased and leaf areas decreased considerably with increasing PBZ dosage, while only P5-treated seedlings showed remarkable difference from the control in chlorophyll contents. The GA3 recovery showed that 15-day height increments of seedlings treated with GA3 were twice more than that without GA3 treatment, and did not differ significantly from the control without PBZ and GA3 treatment. It is concluded that the combined application of PBZ and GA3 can be recommended as a potential tool for regulating growth of B. alnoides seedlings, making it flexible to growing seedlings in the nursery.

Effect of polythene pot thickness on seedling growth of Chrysophyllum albidum G. Don (Ericales: Sapotaceae)

The study investigated the response of tree seedlings to different pot thickness. Chrysophyllum albidum G. Don (Ericales: Sapotaceae) seedlings were subjected to four treatments, T1 = 0.01 mm pot polythene thickness, T2 = 0.02 mm polythene pot thickness, T3 = 0.03 mm polythene pot thickness, T4 = 0.04 mm pot polythene thickness, 0.01 mm served as control. There were four treatments replicated five times making a total of twenty seedlings altogether. The experiment was arranged in Randomized Complete Block Design (RCBD). Growth parameters assessed fortnightly were plant height (cm), stem diameter (mm) and number of leaves. Soil temperature of each treatment at different time intervals were also monitored and recorded. Data recorded were analyzed using descriptive statistics and analysis of variance (ANOVA). The result showed that T1 had the best performance in terms of plant height and stem diameter while equal number of leaves were recorded in all the treatments. Analysis of variance (ANOVA) showed that there were no significant differences among treatments at 5% level of significance. This indicates that polythene pot thickness of 0.01 mm-0.04 mm can be used to raise C. albidum seedlings at the nursery stage. Soil temperature increases with polythene pot thickness. Hence, T4 gave the highest soil temperature of 36.7 oC. Soil temperature and seedlings growth increases with polythene pots thickness. For optimum growth and development of C. albidum seedlings in the nursery 0.01 mm polythene pot should be used.

人口酸性雨・霧およびオゾンがスギに及ぼす影響と近年の汚染状況の変動 : 樹木の衰退現象に関連して

人口酸性雨・霧およびオゾンがスギに及ぼす影響と近年の汚染状況の変動 : 樹木の衰退現象に関連して

Genetic control of growth, biomass allocation, and survival under drought stress in Pinus radiata D. Don seedlings

Drought is one of the critical factors limiting plant growth, and knowledge about genetic adaptation to drought is necessary to develop strategies for successful reforestation on drought-prone sites. In this study, genetic variation was investigated in 98 full- and half-sib radiata pine (Pinus radiata D. Don) families, representing Chilean coastal and interior populations, subjected to two water regimes: well-watered and drought-stressed. Assessed traits, in 5-month-old seedlings, included height (H), diameter (D), height-to-diameter ratio (HDR), dry biomass of needles (NDW), stem (SDW), roots (RDW), and total (TDW), root-to-shoot ratio (RSR), and survival (SUR). After 115 days of treatment, growth, biomass, and survival were nearly two times higher under the well-watered regime than under the stressed one. Families differed significantly in most traits, with individual tree heritabilities ranging from 0.14 for SUR to 0.63 for D in the well-watered treatment. Families from the interior showed the highest heritability for D, SDW, RDW, and TDW when grown in the water-stress treatment. The genetic correlations between treatments were moderately strong, which suggests the presence of a genotype by watering regime interaction. Most traits were strongly correlated (genetic correlations often exceeded 0.40). Compared to the first generation families from coastal sites, the third generation families from the interior sites showed an increase in SUR and RSR. Thus, potential exists to screen families at the seedling stage for drought hardiness and to identify parents from the interior sites with potential to produce a more drought-resistant breed with satisfactory growth rates and yields in dry environments.

Application of longitudinal-wave time-of-flight sound speed measurement to Pinus radiata seedlings

The sound speed of wood is related to important wood quality properties such as the microfibril angle of the S2 layer in the cell wall, stiffness, and shrinkage propensity. Measuring the sound speed of seedling stems has benefits to the forestry industry, potentially enabling early selection of trees that yield better quality wood. A nondamaging longitudinal-wave time-of-flight (LWToF) acoustic technique was used to determine the sound speed of 10 cm long sections of 2-year-old Pinus radiata D. Don seedlings. The measured sections were harvested and acoustic resonance used to determine the sound speed of the sections before and after the bark was removed and after the remaining xylem was dried. A linear relationship between the acoustic resonance sound speed of the dry xylem and the LWToF sound speed of the seedling stem was found (R2 = 0.89). To demonstrate a potential application using the LWToF acoustic technique, it was used as a tool for investigating the effect of various applied stresses on wood properties of a clone of P. radiata. The LWToF sound speed measurements of phytohormone stressed stems were significantly lower than the control stems, indicating the negative impact on stiffness and shrinkage propensity imposed by this treatment.

Anatomical changes of xylem cells in stem of Pinus radiata seedlings exposed to inclination and ethylene

In conifers, relationship between ethylene and the response to inclination are not well understood. The aim of this work was to study the consequence for the application of 2-chloroethyl phosphonic acid (ethephon), compound able to release ethylene, in one-year-old Pinus radiata D. Don seedlings subjected to inclination. In plants exposed to inclination for 15 d, increase in thickness of cell walls, more rounded shape of xylem cells, and accumulation of lignin were observed. Ethephon application accelerated significantly these changes; they can be observed after 5 d of inclination. The quantitative polymerase chain reaction (qPCR) showed up-regulation of transcripts from genes encoding phenylalanine ammonia lyase and cinnamyl alcohol dehydrogenase after inclination and their possible ethylene signal-dependence. As conclusion, morphological changes on stem xylem cells in young seedlings of radiata pine exposed to inclination are similar to those observed in compression wood and they are influenced by ethephon application.

Fertilizer and fungicide use increases the abundance of less beneficial ectomycorrhizal species in a seedling nursery

Ectomycorrhizal (ECM) associations are critical to the establishment and growth of Pinus radiata D. Don seedlings. However, the effect of fertilizer and fungicide applications on the benefits seedlings receive from ECM associations is not clear. We determined if changes to relative ECM taxa abundance on nine-month-old P. radiata seedlings (due to exposure to various combinations of fertilizer and fungicide) were correlated with seedling growth and performance. Rhizopogon rubescens was the most abundant ECM taxa on the seedlings, followed by Wilcoxina mikolae, Hebeloma sp., Tuber sp. and Thelephora terrestris. Increased fertilizer and fungicide application rates substantially decreased the relative abundance of R. rubescens and increased the presence of Hebeloma sp. and W. mikolae. The relative abundance of R. rubescens was positively correlated with foliar concentrations of several nutrients while correlations with the four other dominant ECM taxa were negative in most cases. These correlations were observed across all treatments, regardless of the amounts of fertilizer or fungicide used. Given the effects of fertilizer and fungicide on the relative abundance of R. rubescens, increased chemical use appeared to have offsetting negative effects by encouraging mycorrhization with ECM taxa which provided few significant benefits for the seedlings.

Terpene production and growth of three Pacific Northwest conifers in response to simulated browse and nutrient availability

Natural variation in ungulate browsing behavior interferes with the understanding of plant morphological and biochemical responses to herbivory. To investigate mechanisms for recovery from herbivory, we examined growth patterns and biosynthesis of terpenoids under simulated browse (three clipping intensities) and supplemental mineral nutrition (four levels of controlled-release fertilization) for Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco], western hemlock (Tsuga heterophylla Raf. Sarg.), and western red-cedar (Thuja plicata Donn ex D. Don) seedlings on a reforestation site in Northwestern Oregon, USA, that was fenced to exclude ungulates. Higher clipping intensities increased relative height growth (at cost of diameter growth) for all the species. Only western red-cedar showed a decline in monoterpene concentrations with increasing clipping severity, suggesting prioritization in biosynthesis of terpenoids for this species. Douglas-fir and western hemlock responded to fertilization mostly through increased growth. Western red-cedar growth responses to fertilization were less pronounced, but monoterpene concentrations were 2–3 times higher compared to non-fertilized trees. Douglas-fir and western hemlock browse recovery and responses to fertilization consisted primarily of increased growth, while western red-cedar balanced growth promotion with production of chemical defense compounds. Our data suggests the evolution of species-dependent resource allocation strategies in response to both browse and soil nutrient availability.

Evaluation of Trichoderma spp. and Clonostachys spp. Strains to Control Fusarium circinatum in Pinus radiata Seedlings

The fungus Fusarium circinatum Nirenberg & O�Donnell causes pine pitch canker, an important disease for conifers worldwide. F. circinatum was first detected in Chile in 2001 and to date is present in nurseries and clonal hedges from Libertador General Bernardo O�Higgins Region to Los Rios Region. The purpose of this study was to evaluate the potential of Trichoderma spp. and Clonostachys spp. strains to control F. circinatum in Pinus radiata D. Don seedlings in the absence of other effective control methods. Eighty-one Trichoderma spp. and Clonostachys spp. strains were evaluated through in vitro assays to determine their ability to act as antagonists of F. circinatum and 21 strains were tested for their ability to reduce post-emergence mortality and increase P. radiata survival under greenhouse conditions. During in vitro experiments, 15 strains of Trichoderma inhibited mycelial growth of the pathogen by more than 60% and one strain of Clonostachys showed parasitism of F. circinatum hyphae. Greenhouse experiments showed no control of the disease when the antagonists were added to substrate after the pathogen. However, when the antagonists were added before the pathogen, four strains (Clonostachys UDC-32 and UDC-222 and Trichoderma UDC-23 and UDC-408) reduced post-emergence mortality between 80 and 100%. Among these strains, only Clonostachys UDC-222 significantly increased the survival of P. radiata seedlings. These results showed that Clonostachys UDC-222 has the potential to be used as a biocontrol agent against F. circinatum in the production of P. radiata plants.

Influence of ammonium and nitrate supply on growth, dry matter partitioning, N uptake and photosynthetic capacity of Pinus radiata seedlings

Growth and physiological responses of Pinus radiata D. Don seedlings to a combination of N supply regimes (low N = 1.78 mol m−3, high N = 7.14 mol m−3) and ammonium:nitrate ratios (80:20, 50:50 and 20:80; molar basis) were assessed in a hydroponic experiment run over the course of 105 days. Highly significant (P < 0.001) increases in seedling diameter, height, leaf area and dry mass occurred at lower ammonium:nitrate ratios and were two to fourfold greater than the non-significant (for diameter) to marginally significant (P < 0.05 for other dimensions) increases in these dimensions that occurred with greater N supply. Increases in N supply resulted in a highly significant (P < 0.001) reduction in biomass partitioning to roots and highly significant (P < 0.001) increases in allocation to foliage. The ammonium:nitrate ratio was not found to significantly change biomass partitioning to either foliage, stems or roots. Ammonium and nitrate uptake was significantly influenced by N supply and N form and conformed to ammonium and nitrate concentrations in nutrient solution. Uptake rates of ammonium were twice those of nitrate at comparable concentrations suggesting that P. radiata is in the lower end of the ratio of uptake of ammonium to nitrate reported for conifers (range from 2 to 20 mol mol−1). Despite this, plants growing in high ammonium:nitrate ratios were smaller, exhibited luxurious N consumption and lower N use efficiency. Differences in productivity among treatments were partially explained by greater rates of light-saturated photosynthesis associated with nitrate nutrition.

Root temperature drives winter acclimation of shoot water relations in Cryptomeria japonica seedlings

In many temperate evergreen plant species, reductions in turgor loss point of leaves (Psi(tlp)) and leaf osmotic potential at full turgor (pi(sat)) occur from late summer to winter. To test the hypothesis that this seasonal change in leaf water relations is driven by root temperature, we manipulated the temperature of the roots and shoots of Cryptomeria japonica D. Don seedlings separately. Whole-plant warming diminished the seasonal changes in shoot water relations observed in the control plants, whereas shoot warming did not. Compared with the controls, root warming diminished the change in Psi(tlp) but not in pi(sat), whereas cooling accelerated the seasonal changes in shoot water relations. These results indicate that: (1) temperature responses of roots are involved in the seasonal changes in Psi(tlp) from late summer to winter; and (2) root temperature is partly responsible for the simultaneous changes in pi(sat). Whole-plant cooling caused increased root hydraulic resistance, suggesting that seasonal changes in shoot water relations represent adaptive responses to increased root hydraulic resistance at low root temperatures.

Influence of Ectomycorrhizal Hyphae on Phosphate Fractions and Dissolution of Phosphate Rock in Rhizosphere Soils of Pinus radiata

ABSTRACT A study was conducted to determine the effect of ectomycorrhizal hyphae on phosphate rock dissolution and soil properties in the rhizosphere of one-year-old Pinus radiata D. Don seedlings established on an allophanic soil (Andosol) in the field. High and low ectomycorrhizal hyphal activities were produced in soils inside the lower compartments of rhizosphere study containers by using either 26 μm or < 10 μ m pore-size nylon mesh(es) at the interfaces between the lower and upper compartments. The meshes at the interfaces allowed (26 μm) or reduced (< 10 μ m) hyphae penetration into the lower compartment. Pairs of containers, one with 26 μ m mesh and the other with < 10 μ m mesh, were buried under Pinus radiata seedlings for 10 months in a forest plantation. The effect of ectomycorrhizal (ECM) hyphal activity on phosphate rock dissolution and soil properties was determined. The increased ECM hyphal activity induced increased soil acidification and promoted greater production of acid phosphatase enzyme, causing greater changes in phosphorus (P) fractions in the rhizosphere soils. The increased ECM hyphal activity also stimulated higher dissolution of phosphate rock and mobilization of soil organic P. The results suggest that ECM hyphal strand has a significant role in mobilizing low-solubility P forms and soil organic P for utilization by the tree.

Differential responses of three fungal species to environmental factors and their role in the mycorrhization of Pinus radiata D. Don.

Three ectomycorrhizal (ECM) isolates of Rhizopogon luteolus, R. roseolus and Scleroderma citrinum were found to differ markedly in their in vitro tolerance to adverse conditions limiting fungal growth, i.e. water availability, pH and heavy metal pollution. S. citrinum was the most sensitive, R. luteolus intermediate and R. roseolus the most tolerant species. Pinus radiata D. Don seedlings were inoculated in the laboratory and in a containerised seedling nursery with spore suspensions of the three ECM species. Colonisation percentage was considerably lower under nursery conditions, probably due to competition by native fungi. The effects of nursery ECM inoculation on seedling growth depended on the fungal species. Only R. roseolus-colonised plants showed a significantly higher shoot growth than non-mycorrhizal plants. All three fungi induced significantly higher root dry weights relative to control plants. Despite the low mycorrhizal colonisation, mycorrhization with all three species improved the physiological status of nursery-grown seedlings, e.g. enhanced root enzyme activity, shoot nutrient and pigment content, net photosynthesis rate and water use efficiency. Of the three fungal species, R. roseolus was the most effective; this species was also the most adaptable and showed the greatest range of tolerance to adverse environmental conditions in pure culture. It is, therefore, proposed as a promising fungal species for ECM inoculation of P. radiata in the nursery.

Gas exchange and chlorophyll fluorescence responses of Pinus radiata D. Don seedlings during and after several storage regimes and their effects on post-planting survival

Post-storage gas exchange parameters like CO2 assimilation, stomatal conductance, transpiration, water use efficiency and intercellular CO2 concentrations, together with several chlorophyll a fluorescence parameters: F o, F v, F v/F m, F m/F o and F v/F o were examined in radiata pine (Pinus radiata D. Don) seedlings that were stored for 1, 8 or 15 days at 4° or 10°C with or without soil around the roots. Results were analysed in relation to post-storage water potential and electrolyte leakage in order to forecast their vitality (root growth potential) following cold storage, and post-planting survival potential under optimal conditions. During storage at 4° and 10°C, photosynthesis was reduced, being more pronounced in bare-root seedlings than in seedlings with soil around the roots. The depletion of CO2 assimilation seemed not to be solely a stomatal effect as effects on chloroplasts contributed to this photosynthetic inhibition. Thus, the fall in the ratios F v/F m, F v/F o and F m/F o indicated photochemical apparatus damage during storage. Photosynthetic rate was positively correlated with the root growth index and new root length showing that new root growth is dependent primarily on current photosynthesis. Pre-planting exposure of bare-root radiata pine seedlings to temperatures of 10°C for more than 24 h during transportation or storage is not recommended.