Soil steaming to disinfect barnyardgrass-infested soil masses

Reusing soil can reduce environmental impacts associated with obtaining natural fresh soil during road construction and analogous activities. However, the movement and reuse of soils can spread numerous plant diseases and pests, including propagules of weeds and invasive alien plant species. To avoid the spread of barnyardgrass in reused soil, its seeds must be killed before that soil is spread to new areas. We investigated the possibility of thermal control of barnyardgrass seeds using a prototype of a stationary soil steaming device. One Polish and four Norwegian seed populations were examined for thermal sensitivity. To mimic a natural range in seed moisture content, dried seeds were moistened for 0, 12, 24, or 48 h before steaming. To find effective soil temperatures and whether exposure duration is important, we tested target soil temperatures in the range 60 to 99 C at an exposure duration of 90 s (Experiment 1) and exposure durations of 30, 90, or 180 s with a target temperature of 99 C (Experiment 2). In a third experiment, we tested exposure durations of 90, 180, and 540 s at 99 C (Experiment 3). Obtaining target temperatures was challenging. For target temperatures of 60, 70, 80, and 99 C, the actual temperatures obtained were 59 to 69, 74 to 76, 77 to 83, and 94 to 99 C, respectively. After steaming treatments, seed germination was followed for 28 d in a greenhouse. Maximum soil temperature affected seed germination, but exposure duration did not. Seed premoistening was of influence but varied among temperatures and populations. The relationships between maximum soil temperature and seed germination were described by a common dose–response function. Seed germination was reduced by 50% when the maximum soil temperature reached 62 to 68 C and 90% at 76 to 86 C. For total weed control, 94 C was required in four populations, whereas 79 C was sufficient in one Norwegian population.Soil steaming to disinfect barnyardgrass-infested soil massespublishedVersio

Growth pattern of Juncus effusus and Juncus conglomeratus in response to cutting frequency

Increasing abundance of Juncus effusus (soft rush) and Juncus conglomeratus (compact rush) in pastures and meadows in western Norway has caused reductions in forage yield and quality in recent decades. Understanding plant development and regrowth following cutting is essential in devising cost-effective means to control rushes. In a field experiment in western Norway, we investigated development of above- and below-ground fractions of rush from seedlings to three-year-old plants, including the impact on vigour of disturbing growth by different cutting frequencies during the period 2009–2012. Each year, the plants were exposed to one or two annual cuts or left untreated and five destructive samplings were performed from March to early December. Juncus effusus showed significantly more vigorous growth than Juncus conglomeratus in the last two years of the study period. The above-ground:below-ground biomass ratio of both species increased mainly in spring and early summer and was reduced in late summer and autumn. Removal of aerial shoots also reduced the below-ground fraction of both species. One annual cut in July effectively reduced biomass production in both species by 30–82%, which was only a slightly smaller reduction than with two annual cuts, in June and August. Mechanical control measures such as cutting can thus effectively reduce rush vigour when performed late in the growing season.Growth pattern of Juncus effusus and Juncus conglomeratus in response to cutting frequencypublishedVersio

Håndtering av jordmasser med fremmede invaderende karplanter gjennom landbruket

Store mengder god jord med frø eller rotstengler av fremmede invaderende karplanter deponeres hvert år. For en mer bærekraftig forvaltning av jordressurser ønsket Statens vegvesen å undersøke om slik jord fra veianlegg isteden kan kanaliseres til jordbruket der vanlig ugraskontroll og drift forhåpentligvis kan kontrollere de uønskede artene. I prosjektet FoU-forsøk «Håndtering av jordmasser infisert av fremme karplanter gjennom landbruket» gjennomførte vi tre forsøk der vi 1. undersøkte etablering av kanadagullris fra lagret A-sjikt tilbakeført til eng, 2. etablering av kanadagullris fra infisert jord lagt ut på arealer til korndyrking, og 3. bruk av geiter til å kontrollere slireknearter i infisert jord lagt ut til beite. Resultatene fra disse forsøkene presenteres i denne rapporten. Resultatene viser at disse tilnærmingene kan fungere, men effektene må dokumenteres bedre.Håndtering av jordmasser med fremmede invaderende karplanter gjennom landbruketpublishedVersio

Biologisk veiledningsprøving 2022. Ugrasmidler

I denne rapporten presenteres resultater fra biologisk veiledningsprøving av ugrasmidler; mot ugras i golfgras, mot ugras i vårkorn inkl. testing av VIPS-Ugras, mot fangvekster og ugras i utendørs småskalaforsøk, mot ugras i potet under plast/fiberduk, til nedvisning av potetris, mot søtvierarter uten kultur, mot ugras og jordbærutløpere i jordbær og mot ugras i eple, samt ulike strategier mot ugras i gulrot og rotpersille.Biologisk veiledningsprøving 2022. UgrasmidlerpublishedVersio

Biologisk veiledningsprøving 2021. Ugrasmidler

I denne rapporten presenteres resultater fra biologisk veiledningsprøving av ugrasmidler i grasfrøeng, vårkorn, potet, gulrot under plast og på friland, rotpersille, jordbær, bringebær og eple

Stationary Soil Steaming to Combat Invasive Plant Species for Soil Relocation

publishedVersio

Biologisk veiledningsprøving 2021. Ugrasmidler

I denne rapporten presenteres resultater fra biologisk veiledningsprøving av ugrasmidler i grasfrøeng, vårkorn, potet, gulrot under plast og på friland, rotpersille, jordbær, bringebær og eple.publishedVersio

Soil steaming to disinfect barnyardgrass-infested soil masses

Reusing soil can reduce environmental impacts associated with obtaining natural fresh soil during road construction and analogous activities. However, the movement and reuse of soils can spread numerous plant diseases and pests, including propagules of weeds and invasive alien plant species. To avoid the spread of barnyardgrass in reused soil, its seeds must be killed before that soil is spread to new areas. We investigated the possibility of thermal control of barnyardgrass seeds using a prototype of a stationary soil steaming device. One Polish and four Norwegian seed populations were examined for thermal sensitivity. To mimic a natural range in seed moisture content, dried seeds were moistened for 0, 12, 24, or 48 h before steaming. To find effective soil temperatures and whether exposure duration is important, we tested target soil temperatures in the range 60 to 99 C at an exposure duration of 90 s (Experiment 1) and exposure durations of 30, 90, or 180 s with a target temperature of 99 C (Experiment 2). In a third experiment, we tested exposure durations of 90, 180, and 540 s at 99 C (Experiment 3). Obtaining target temperatures was challenging. For target temperatures of 60, 70, 80, and 99 C, the actual temperatures obtained were 59 to 69, 74 to 76, 77 to 83, and 94 to 99 C, respectively. After steaming treatments, seed germination was followed for 28 d in a greenhouse. Maximum soil temperature affected seed germination, but exposure duration did not. Seed premoistening was of influence but varied among temperatures and populations. The relationships between maximum soil temperature and seed germination were described by a common dose–response function. Seed germination was reduced by 50% when the maximum soil temperature reached 62 to 68 C and 90% at 76 to 86 C. For total weed control, 94 C was required in four populations, whereas 79 C was sufficient in one Norwegian population

Biologisk veiledningsprøving 2020. Ugrasmidler

I denne rapporten presenteres resultater fra biologisk veiledningsprøving av ugrasmidler i gras- og kløverfrøeng, vår- og høstkorn, åkerbønne, potet, blomkål, gulrot under plast og på friland, rotpersille og jordbær.publishedVersio

Tankblandinger av ugrasmidler for bekjemping av tofrøblada ugras i gjenlegg og frøeng av timotei og engsvingel

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