The effects of trinexapac-ethyl on Pinus sylvestris and Picea abies
The use of so-called micro-plant propagation have become a well-adapted cultivation technique in Swedish forestry nurseries. Although this production method has many advantages, a commonly occurring problem is that the young plants, after trans- plantation in the nursery, have an underdeveloped root...
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| Formato: | M2 |
| Lenguaje: | Inglés sueco |
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SLU/Department of Plant Biology (from 140101)
2018
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| Materias: |
| _version_ | 1855572221198598144 |
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| author | Bengtsson, Emil |
| author_browse | Bengtsson, Emil |
| author_facet | Bengtsson, Emil |
| author_sort | Bengtsson, Emil |
| collection | Epsilon Archive for Student Projects |
| description | The use of so-called micro-plant propagation have become a well-adapted cultivation technique in Swedish forestry nurseries. Although this production method has many advantages, a commonly occurring problem is that the young plants, after trans- plantation in the nursery, have an underdeveloped root system when the shoot part have reached desired length. Currently used methods to control the plant growth in a desired way involves long-night treatment and exposure to different stresses such as drought or nutrient deficiency. Unfortunately, long-night treatment requires expensive equipment and stressing might cause injury to the plants. Alternative methods to control plant growth are therefore sought after by the forestry industry.
One of these alternative methods could potentially be the use of plant growth regulators (PGRs) which have been used for a long time in the agricultural sector, mainly to reduce the risk of lodging in cereals. There is however a key difference between the agricultural sector and the forestry industry – all plants grown as crops are members of the angiosperms, unlike the forestry plants which are dominated by gymnosperms. Research on PGRs have so far been focused on angiosperms exclusively. In this study, the effects of the substance trinexapac-ethyl on two economical important species of trees, Scots pine (Pinus sylvestris) and Norway spruce (Picea abies), were examined. Trinexapac-ethyl works by inhibition of multiple steps in the biosynthesis of gibberellin, an important plant hormone for length growth.
Trinexapac-ethyl was applied in the form of Moddus Start (250 g L-1 of a.i., Syngenta AG) in dosages of 0.3, 0.6 or 1.2 L ha-1, either all at once or divided into two equally large amounts. There was three different occasions of applications: right after transplantation to cultivation cassettes, when desired shoot length had been reached and four weeks after the first treatment (if any). Both species were analysed by measurements of shoot length and stem diameter, weighing of the root and shoot parts separately and comparing their dry matter proportion, as well as ocular screening of any morphological changes. The frequency of crown buds in P. sylvestris was also determined and P. abies was examined via microscopy analysis.
The results indicate none or very modest growth regulating effect of the trinexapacethyl when applied to P. sylvestris. The substance did however have a more profound effect on the P. abies – growth regulating effect was observed for both shoot length and stem diameter in two out of three trial lanes, and all treated groups had an increase in their root/shoot proportion. Meanwhile, microscopy analysis revealed no harmful effects on the buds of P. abies. No other toxic effect of the trinexapac-ethyl could be observed on any of the species. Trinexapac-ethyl therefore seem to have potential as a PGR for the P. abies, but the substance needs further evaluation before any large-scale use. |
| format | M2 |
| id | RepoSLU13296 |
| institution | Swedish University of Agricultural Sciences |
| language | Inglés swe |
| publishDate | 2018 |
| publishDateSort | 2018 |
| publisher | SLU/Department of Plant Biology (from 140101) |
| publisherStr | SLU/Department of Plant Biology (from 140101) |
| record_format | eprints |
| spelling | RepoSLU132962018-05-30T11:50:43Z The effects of trinexapac-ethyl on Pinus sylvestris and Picea abies Bengtsson, Emil GA gibberellin Norway spruce PGR phytohormone Picea abies Pinus sylvestris plant growth regulator Scots pine trinexapac-ethyl The use of so-called micro-plant propagation have become a well-adapted cultivation technique in Swedish forestry nurseries. Although this production method has many advantages, a commonly occurring problem is that the young plants, after trans- plantation in the nursery, have an underdeveloped root system when the shoot part have reached desired length. Currently used methods to control the plant growth in a desired way involves long-night treatment and exposure to different stresses such as drought or nutrient deficiency. Unfortunately, long-night treatment requires expensive equipment and stressing might cause injury to the plants. Alternative methods to control plant growth are therefore sought after by the forestry industry. One of these alternative methods could potentially be the use of plant growth regulators (PGRs) which have been used for a long time in the agricultural sector, mainly to reduce the risk of lodging in cereals. There is however a key difference between the agricultural sector and the forestry industry – all plants grown as crops are members of the angiosperms, unlike the forestry plants which are dominated by gymnosperms. Research on PGRs have so far been focused on angiosperms exclusively. In this study, the effects of the substance trinexapac-ethyl on two economical important species of trees, Scots pine (Pinus sylvestris) and Norway spruce (Picea abies), were examined. Trinexapac-ethyl works by inhibition of multiple steps in the biosynthesis of gibberellin, an important plant hormone for length growth. Trinexapac-ethyl was applied in the form of Moddus Start (250 g L-1 of a.i., Syngenta AG) in dosages of 0.3, 0.6 or 1.2 L ha-1, either all at once or divided into two equally large amounts. There was three different occasions of applications: right after transplantation to cultivation cassettes, when desired shoot length had been reached and four weeks after the first treatment (if any). Both species were analysed by measurements of shoot length and stem diameter, weighing of the root and shoot parts separately and comparing their dry matter proportion, as well as ocular screening of any morphological changes. The frequency of crown buds in P. sylvestris was also determined and P. abies was examined via microscopy analysis. The results indicate none or very modest growth regulating effect of the trinexapacethyl when applied to P. sylvestris. The substance did however have a more profound effect on the P. abies – growth regulating effect was observed for both shoot length and stem diameter in two out of three trial lanes, and all treated groups had an increase in their root/shoot proportion. Meanwhile, microscopy analysis revealed no harmful effects on the buds of P. abies. No other toxic effect of the trinexapac-ethyl could be observed on any of the species. Trinexapac-ethyl therefore seem to have potential as a PGR for the P. abies, but the substance needs further evaluation before any large-scale use. Användandet av s.k. mikroplantor har blivit en allt vanligare metod på svenska skogsplantskolor. Även om det finns många fördelar med denna produktionsteknik förekommer det dock problem med att de omplanterade färdigodlade plantorna har ett alltför svagt utvecklat rotsystem när skottdelen nått målhöjd på plantskolorna. Idag används metoder som långnattsbehandling och stressning av olika slag, t.ex. exponering för vatten- eller näringsbrist, för att kontrollera plantornas tillväxt. Tyvärr kräver långnattsbehandling dyr utrustning och det är riskabelt att utsätta plantorna för vatten- eller näringsbrist. Alternativa tillvägagångssätt för att styra tillväxten eftersöks därför av skogsindustrin. En av dessa alternativa metoder skulle kunna vara användandet av tillväxt- regulatorer som sedan länge har etablerat sig inom jordbrukssektorn, främst för att minska risken för liggsäd. Det finns dock en viktig skillnad mellan jord- och skogsbruk – samtliga grödor tillhör de gömfröiga växterna medan skogsbruket domineras av nakenfröiga växter. Forskning om tillväxtregulatorer har hittills enbart fokuserat på gömfröiga växter. I detta arbete undersöktes effekten av substansen trinexapak-etyl på två ekonomiska viktiga trädslag, tall (Pinus sylvestris) och gran (Picea abies). Trinexapak-etyl fungerar genom att hämma flera steg i gibberellinsyntesen, ett växthormon viktigt för plantors höjdtillväxt. Trinexapak-etyl applicerades i form av Moddus Start (250 g L-1 aktiv substans, Syngenta AG) i doser om 0,3, 0,6 eller 1,2 L ha-1, antingen allt på en gång eller uppdelat i två lika stora givor. Behandlingarna utfördes vid tre olika tidpunkter: strax efter omplantering till odlingskassetter, när önskad skotthöjd hade nåtts samt fyra veckor efter första behandlingen (om någon sådan fanns). Båda arterna analyserades genom mätning av såväl skottlängd som stamdiameter, separat vägning av rot- systemet och skottdelen vars torrsubstansvikt (TS-vikt) sedan jämfördes, samt okulär bedömning av eventuella morfologiska skillnader. Frekvensen kronknoppar i P. sylvestris bestämdes och P. abies analyserades via mikroskopering. Resultaten visar på inga eller mycket små tillväxtreglerande egenskaper av trinexapak-etyl då P. sylvestris behandlades. Substansen hade emellertid starkare påverkan på P. abies – tillväxtreglerande effekt observerades på såväl skottlängd som stamdiameter i två av tre försöksled, och samtliga grupper hade en ökning av rot/skott-kvot. Mikroskoperingen påvisade inte någon skada på knopparna i P. abies. Inga andra toxiska effekter av trinexapak-etyl kunde identifieras på någon utav arterna. Det tycks alltså finnas potential att använda trinexapak-etyl som tillväxt- regulator för P. abies, men mer utvärdering av substansen måste ske innan den kan börja användas i någon större skala. SLU/Department of Plant Biology (from 140101) 2018 M2 eng swe https://stud.epsilon.slu.se/13296/ |
| spellingShingle | GA gibberellin Norway spruce PGR phytohormone Picea abies Pinus sylvestris plant growth regulator Scots pine trinexapac-ethyl Bengtsson, Emil The effects of trinexapac-ethyl on Pinus sylvestris and Picea abies |
| title | The effects of trinexapac-ethyl on
Pinus sylvestris and Picea abies |
| title_full | The effects of trinexapac-ethyl on
Pinus sylvestris and Picea abies |
| title_fullStr | The effects of trinexapac-ethyl on
Pinus sylvestris and Picea abies |
| title_full_unstemmed | The effects of trinexapac-ethyl on
Pinus sylvestris and Picea abies |
| title_short | The effects of trinexapac-ethyl on
Pinus sylvestris and Picea abies |
| title_sort | effects of trinexapac-ethyl on
pinus sylvestris and picea abies |
| topic | GA gibberellin Norway spruce PGR phytohormone Picea abies Pinus sylvestris plant growth regulator Scots pine trinexapac-ethyl |