Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2022
Forfattere
Erik Framstad Gunnar Austrheim Marianne Evju Line Johansen Anders Lorentzen Kolstad Anders Lyngstad Siri Lie Olsen Tommy Prestø Vigdis Vandvik Vibekke Vange Liv Guri VelleSammendrag
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Sammendrag
Established invasive alien plant species make it difficult and costly to move and make use of infested soil in public and private construction work. Stationary soil steaming as a non-chemical control method has the potential to disinfect soil masses contaminated with seeds and other propagative plant materials. The outcome can vary depending on steaming temperature and duration. Higher temperatures and longer durations are relatively more efficient but may also have side-effects including change in soil physical and chemical characteristics. Barnyard grass (Echinochloa crus-galli) is among troublesome invasive species in Norway. We have tested different steam duration at 99°C to find the possible lowest effective exposure duration for killing seeds of this annual grass species. Four replications of 40 barnyard grass dry seeds of one population were placed in polypropylene-fleece bags (9*7 cm), moistened for 12 hours, and covered by the soil at a depth of 7 cm in 60*40*20 cm boxes. The boxes with soil and bags were steamed at 99°C for 1.5, 3 and 9 min. The bags including steamed seeds were taken out, opened, placed on soil surface in pots and covered by a thin layer of soil. The pots were placed in greenhouse and watered from below and seed germination was followed for a month. Moistened non-steamed seeds were used as control. It was shown that steaming at 99°C gave 0% germination indicating that 100% of the seeds were killed regardless of exposure duration while in the control seed germination was 100%. Consequently, to achieve an efficacy of 100%, exposure duration of 1.5 min would be enough. Finding the lowest possible steam temperature and exposure duration to get the highest possible seed killing in a seed mixture of different plant species as well as other factors to increase the heat transferability are under investigation. Keywords: Echinochloa crus-galli; Resource recovery; Steaming temperature and duration; Thermal soil disinfection
Sammendrag
Harvest Weed Seed Control (HWSC) systems are used to collect and/or kill weed seeds in the chaff fraction during grain harvest. While collecting chaff reduces the weed infestation in the following years, a new biomass feedstock is created. Chaff mainly consists of husk and straw. There is a potential energetic utilization of chaff. It can also be used as a material for construction (e.g., insulating boards, cardboard, bedding), soil improvement (e.g., mulch, mushroom compost) and agricultural use (e.g., weed growth inhibitor, animal diet). Using chaff directly is unfavorable because of low bulk density; therefore, compressing chaff into pellets optimizes its handling. We have assessed how pelletizing would affect germination of weed seeds bearing in the chaff if the collected chaff is pelletized for further utilization. To test this, we mixed original wheat chaff and fine wheat chaff (pretreated by sieving) with each of the weed species Tripleurospermum inodorum and Centarea cyanus seeds separately. Approximately 2000 seeds of each weed species were added to 2500 g of chaff (20 % moisture). Samples were pelletized using the Kahl Pelleting Press 14-175. Each treatment was replicated four times. Afterwards pelletized samples were spread evenly on the soil surface in 14 × 16 cm boxes and covered by a thin layer of soil/sand. Unpelletized chaff samples were used as control. Boxes were placed in greenhouse and watered from the bottom and seed germination was followed for a month. While on average 22 and 59 % seed germination of T. inodorum and C. cyanus were observed in wheat chaff control samples respectively, no weed seed germination was observed in pelletized fine and original wheat chaff samples. Consequently, we find that the pelletizing process of collected chaff destroys the weed seeds in it.
Sammendrag
VIPS is a technology platform for prognosis, monitoring and decision support for integrated pest management in crops in Norway. The service facilitates access to a Danish decision support tool, IPMwise, for the management of weeds. This tool, called VIPS-weeds in Norway, is adjusted to the Norwegian conditions for cereals. VIPS-weeds selects and adjusts the dose of herbicides according to weed species, weed density and temperature. The tool is being tested each year for local adaptations and updating. In 2021, four experiments were performed in spring wheat and barley. The experiments were designed in completely randomised blocks with three replications, and each included a control (unsprayed), a VIPS-weeds, and an adviser choice plot as well as plots for a variety of herbicides that are common in these crops. The weed species and density, development stage and possible herbicide resistance of each species in the control plots as well as crop information and temperature data were registered in VIPS-weeds three days before the normal spraying time. The suggested herbicides (set to be suggested based on the price) were applied to the VIPS-weeds plots. The effect of suggested herbicides and their dose was assessed as the reduction of weed coverage (%) in sprayed plots compared to the control plots 3-4 weeks after spraying. The average efficacy targets for the weed species (observed at least in two fields) Spergula arvensis, Viola sp., Stellaria media, Galeopsis sp., Chenopodium album, and Fumaria officinalis were predicted to be at 91, 84, 65, 83, 80, and 72% respectively, by VIPS-weeds. The results showed an average efficacy of 45, 58, 79, 80, 91 and 82% for these weeds, respectively. The VIPS-weeds solution was economically reasonable and gave similar results as adviser choice in terms of weed control and yield.
Sammendrag
Invasive plant propagative material can be introduced to new regions as contaminants in soil. Therefore, moving soil should be done only when the soil has been verified to be free of invasive species. Stationary soil steaming as a non-chemical control method has the potential to disinfect soil masses contaminated with invasive species. We investigated the possibility of thermal control of propagative material of Bohemian knotweed (Reynoutria × bohemica) in two experiments using a prototype of a soil steaming device. Five soil temperatures of 60, 70, 80, 90 and 99 °C with an exposure duration of 3 min were tested. In each replicate and target temperature, rhizome cuttings containing at least two buds and shoot clumps were placed at the bottom of a plastic perforated basket and covered by a 7-cm soil layer. Each basket was placed in the steaming container and steam was released from the top and vacuumed from the bottom. Soil temperature was monitored by 10 thermocouples and steaming was stopped when 5 of the thermocouples had reached the target temperature. The basket was then removed from the steaming container after 3 min. Plant materials were taken out and planted in pots. Buds sprouting was followed for 8 weeks. Non-steamed plant materials were used as controls. Results showed 100% rhizome death at soil temperatures of ≥70 and 99 °C in the first and second experiments, respectively. Shoot clumps death was obtained at ≥90 °C in both experiments. These results showed that steaming at 99 °C for 3 min can guarantee control of Bohemian knotweed in infested soils supporting the steam treatment as a potential method of disinfecting soil against invasive species. However, depending on the intended re-use of the soil, further studies are needed on the effect of potential negative impacts of high temperatures on the soil quality.
Forfattere
Magnus StenbrendenSammendrag
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Sammendrag
Galera, Matrigon 72SG and their parallel products are approved for weed control in oilseed rape every fourth years. In 2017, clopyralid, which is the active component in the herbicides, was found in Danish honey for the first time when honey from 2016 and 2017 was tested. The maximum acceptable residue level for clopyralid in honey has not been verified scientifically but is set at 0.05 mg/kg, which is not considered harmful to humans. However, 0.1 mg/kg releases a ban on sale of honey. In several of the tested honey samples from both years the amount of clopyralid was higher than 0.1 mg/kg. As nearly 50% of the Danish honey stems from nectar collected from rapeseed the use of clopyralid in oilseed rape poses a very serious economic problem for Danish beekeepers, and already in 2017, the sale of several spring honey lots was rejected. In 2019 and 2020, we tested the following hypotheses 1) nectar and pollen, collected from flowers of winter oilseed rape sprayed with clopyralid according to the regulations may contain clopyralid; 2) honey and pollen collected from beehives placed next to winter oilseed rape fields sprayed with clopyralid according to the regulations may contain clopyralid. Residues of clopyralid were found in all nectar, pollen and honey samples from treated plots and fields. In a large part of the samples, more than 0.1 mg clopyralid/kg was detected, which would have resulted in a ban on the sale of honey. The perspectives of the results are discussed.
Sammendrag
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Forfattere
Ishita Ahuja Inger Sundheim Fløistad Per Grande Øyvind Meland Edvardsen Adam O’Toole Arne SteffenremSammendrag
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Sammendrag
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