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.
2010
Forfattere
Jim Treasurer Oddvar Ottesen Julie Maguire Nina Zhuravleva Åsbjørn Karlsen Celine ReboursSammendrag
Biological control of sea lice with wrasse is considered an alternative to medicines and can form part of an integrated sea lice management plan. The use of wrasse can also have benefits in organic fish production where there is a limitation on the use of medicines. While wrasse have been used previously in sea lice control there have been reservations about fishing the wrasse from wild stocks with possible erosion of local stocks and changes in population structure. There have also been concerns regarding potential diseases that might be transferred to the farmed setting by using wild fish. An EU Northern Periphery Project entitled "Ecofish" has been established to examine the rearing of ballan wrasse Labrus bergylta and the application of this species in sea lice control. While other species of wrasse such as corkwing and goldsinny have been reared previously, there has been no report of rearing success with ballan wrasse. This species has been shown to be a successful cleaner of sea lice in preliminary trials and may be more suitable than smaller wrasse with larger second production year salmon. This poster will present the aims of the organic fish project to establish broodstock populations of ballan wrasse, to develop rearing techniques for ballan wrasse in the hatchery phase, to examine the ongrowing of wrasse, to establish good husbandry of wrasse in salmon and cod cages, and to evaluate how effective ballan wrasse are in cleaning lice from both salmon and cod stocks.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Reidun PommerescheSammendrag
Det er ikke registrert sammendrag
Forfattere
Håvard SteinshamnSammendrag
Literature data from experiments with lactating dairy cows offered silage-based diets was reviewed to evaluate the effects of the grassland legume species Trifolium repens (WC, white clover), Trifolium pratense (RC, red clover) and Medicago sativa (M, lucerne) on feed intake, milk production and milkquality. Seven data sets were created to compare grass silage (G) with grassland legumes in general (L), G with RC, G with WC, G with M, RC with WC, RC with M and different silage proportions of RC. Daily dry matter intake and milk yield were on average 1.6 and 1.6 kg, respectively, higher and milk fat content 1.2 g/kg milk lower on L than on G based diets. Similar differences were found when G was compared with RC or WC diets. Cows offered WC yielded 1.1 kg/d more milk than RC, and milk produced on WC and M contained 0.7 g more protein per kg than milk from RC diets. Increasing the silage diet RC proportion from 0.5 to 1.0 also decreased the milk protein content by 0.8 g/kg milk. RC increased the level of poly-unsaturated fatty acids, particularly C18:3n-3, and isoflavones, particularly equol, in milk. Effects are discussed in relation to plant cell wall characteristics, plant chemical constituents and changes in rumen digestion to explain the origin of the differences in intake, milk yield and milk composition.
Forfattere
Johannes Andre Folkestad Liv Ostrem Jan NetlandSammendrag
Soft rush (Juncus effusus L.) and compact rush (J.conglomeratus L.) have spread significantly in coastal parts of Norway during the past two decades, an increase that seems to have coincided with an observed rise in winter temperatures. This study investigated the effects of exposure to frost on plant regrowth of both species. Exposure to temperatures of -8 to -10°C for more than 6 h resulted in significantly lower regrowth ability compared with non-frozen controls. Regrowth was still observed after 72 h, but with significantly lower regrowth ability for soft rush than for compact rush at 48h and 72 h. These initial results indicate that soft rush is more susceptible to frost than compact rush. However, the species did not differ significantly in frost tolerance.
Forfattere
Alemayehu Chala Tameru Alemu Louis K Prom Anne Marte TronsmoSammendrag
The severity and temporal dynamics of anthracnose on susceptible (BTx623 and AL70) and resistant lines (2001 PWColl No. 022 and 2001 HararghieColl No. 12) were studied in field plots during the 2007 and 2008 growing seasons in southern Ethiopia. The initial, final and mean anthracnose severities and area under disease progress curves were used as criteria to evaluate the response of the genotypes. Over the two years, the initial, final and mean anthracnose severities ranged from 0.88 to 16.13%, 7.56 to 78.38% and 3.57 to 46%, respectively, while area under disease progress curve averaged for the two years ranged from 221.31 to 2951.88. All the evaluation criteria showed highly significant variations (p<0.0001) among the genotypes and the Ethiopian genotype 2001 PWColl No. 022 consistently had the lowest disease levels regardless of the evaluation criteria and growing season. The disease appeared rather late and progressed slowly on this genotype. On the other hand, the exotic cultivar, BTx623, showed the most sever anthracnose infection. Initial anthracnose severity was significantly higher and the disease developed rapidly on BTx623 than on the other three genotypes. The other two genotypes showed intermediate response and progression of the disease. Correlation and regression analyses revealed a significantly strong association between rainfall and anthracnose severity but temperature appeared to have little/no impact on the development of anthracnose in the field. The present study confirmed the effect of both host genotypes and weather, particularly rain on anthracnose development. The Ethiopian sorghum genotype 2001 PWColl No. 022 was recommended as stable source of resistance against this important disease.
Sammendrag
Soil biological properties and CO 2 emission were compared in undisturbed grass and regularly disked rows of a peach plantation. Higher nutrient content and biological activity were found in the undisturbed, grass-covered rows. Significantly higher CO 2 fluxes were measured in this treatment at almost all the measurement times, in all the soil water content ranges, except the one in which the volumetric soil water content was higher than 45%. The obtained results indicated that in addition to the favourable effect of soil tillage on soil aeration, regular soil disturbance reduces soil microbial activity and soil CO 2 emission
Sammendrag
Development of ontogenic resistance to powdery mildew (Podosphaera aphanis) on strawberry leaves has been reported, however, the components of resistance have not been elucidated. Five developmental stages of strawberry leaves were identified and assigned numerical values from newly emerged and unexpanded (S1) to fully expanded and dark green (S5) of cvs. Korona and Senga Sengana. The upper and lower surface of the leaves were inoculated from each of the five leaf developmental stages and incubated under controlled conditions. The effect of leaf age on germination, infection efficiency, latency period, and sporulation were later evaluated. All responses were significantly (p = 0.05) affected by leaf age. Germination percentage, infection efficiency, and sporulation were highest, and latent periods were shortest on S1 leaves of both cultivars. On Senga Sengana, germinating conidia produced fewer secondary hyphae during infection. Conidia produced very few secondary hyphae and did not sporulate on S3 leaves, and no infections established on S4 or S5 leaves. The high success of infection and colonization of P. aphanis on S1 leaves indicates that disease is established preferentially on emergent and expanding leaves and these should be the target of management strategies.
Sammendrag
Development of ontogenic resistance to powdery mildew (Podosphaera aphanis) on strawberry leaves has been reported, however, the components of resistance have not been elucidated. Five developmental stages of strawberry leaves were identified and assigned numerical values from newly emerged and unexpanded (S1) to fully expanded and dark green (S5) of cvs. Korona and Senga Sengana. The upper and lower surface of the leaves were inoculated from each of the five leaf developmental stages and incubated under controlled conditions. The effect of leaf age on germination, infection efficiency, latency period, and sporulation were later evaluated. All responses were significantly (p = 0.05) affected by leaf age. Germination percentage, infection efficiency, and sporulation were highest, and latent periods were shortest on S1 leaves of both cultivars. On Senga Sengana, germinating conidia produced fewer secondary hyphae during infection. Conidia produced very few secondary hyphae and did not sporulate on S3 leaves, and no infections established on S4 or S5 leaves. The high success of infection and colonization of P. aphanis on S1 leaves indicates that disease is established preferentially on emergent and expanding leaves and these should be the target of management strategies.
Sammendrag
Det er ikke registrert sammendrag