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- Berglund, Torkel, et al.
(author)
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Protection of spruce seedlings against pine weevil attacks by treatment of seeds or seedlings with nicotinamide, nicotinic acid and jasmonic acid
- 2016
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In: Forestry (London). - : Oxford University Press. - 0015-752X .- 1464-3626. ; 89:2, s. 127-135
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Journal article (peer-reviewed)abstract
- Sustainable methods are required to protect newly planted tree seedlings from insect herbivore attack. To this end, here Norway spruce (Picea abies (L.) Karst.) seeds were treated with 2.5 mM nicotinamide (NIC), 2.5 mM nicotinic acid (NIA), 3 mM jasmonic acid (JA) or 0.2 mM 5-azacytidine (5-Aza), and 6-month-old seedlings grown from these seeds were planted at a reforestation area in central Sweden. Attack by pine weevils (Hylobius abietis) was reduced by 50 per cent by NIC treatment, 62.5 per cent by JA treatment and 25 per cent by 5-Aza treatment, when compared with seedlings grown from untreated seeds. Watering 18-month-old spruce seedlings with 2 mM NIC or 2 mM NIA did reduce attack during the first season in the field by 40 and 53 per cent, respectively, compared with untreated plants. Girdling was also reduced by the different treatments. Analysis of conifer seedlings treated with 5-Aza points at a possible involvement of epigenetic mechanisms in this defensive capacity. This is supported by a reduced level of DNA methylation in the needles of young spruce seedlings grown in a greenhouse from NIC-treated seeds. Seed treatment for seedling defense potentiation is simple, inexpensive and also a new approach for forestry with many potential applications.
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| 4. |
- Danielsson, Marie, et al.
(author)
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Mini-seedlings of Picea abies are less attacked by Hylobius abietis than conventional ones : Is plant chemistry the explanation?
- 2008
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In: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 23:4, s. 299-306
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Journal article (peer-reviewed)abstract
- The pine weevil, Hylobius abietis (L.), is a major pest in conifer reforestation areas in the Palaearctic region. Size and chemistry of the seedlings may explain the damage rates in plantations. The performance of 10-week containerized seedlings (mini-seedlings) was compared with 1-year-old conventional seedlings of Norway spruce, Picea abies (L.), in a field experiment in central Sweden. After 2 years the weevil damage was lower for the mini-seedlings than for the conventional seedlings (3.5 vs 55%). After 3 years, the overall survival was 82 and 75%, respectively. Weevil damage was the main cause of mortality for conventional seedlings, whereas mini-seedlings mainly died from drought. Volatiles of the two seedling types were compared by solid-phase microextraction-gas chromatography -mass spectrometry (SPME-GC-MS). Unwounded mini-seedlings and conventional seedlings differed in their compositions of monoterpenes and sesquiterpenes. Miniseedlings mainly emitted limonene, known to be repellent to the pine weevil. When wounded, green leaf volatiles were released by mini-seedlings while the pine weevil attractant alpha-pinene was released by conventional seedlings. Volatiles may partly explain the mini-seedlings' resistance against weevil attack. Further studies are needed to clarify how long this miniseedling effect remains.
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| 6. |
- Flöjstad, Inger, et al.
(author)
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Effekt av markberedning ved bruk av miniplanter og konvensjonelle pluggplanter
- 2007
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In: Foryngelse for et bærekraftig skogbruk. - Ås : Forskning fra Skog og landskap. ; , s. 39-42
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Book chapter (other academic/artistic)abstract
- A field study in Akershus County in south-eastern Norway was established in order to compare different seedling types. The experiment includes 10 week-old containerized seedlings (mini seedling), in addition to 1 and 2 year old commercial grown seedlings. The mini seedlings were not treated with insecticides against pine weevil before planting. All seedlings were tested both with and without mechanical soil scarification. Mini seedlings were sensitive for frost heaving, but the growth rate were comparable to the commercial seedlings, if they were successfully established. Only limited damages caused by the pine weevil were observed in the study.
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