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.
2009
Sammendrag
Mite damage is often considered a spray induced problem. We monitored 12 Norwegian strawberry fields, 6 organic and 6 conventional fields, by sampling leaves two times per year for two years. Young folded leaflets were visually inspected for eggs and adults of strawberry mite (Phytonemus pallidus) and completely unfolded leaves were used for extraction of mobile stages of two-spotted spider mite (Tetranychys urticae). The spider mites were examined for infection of the mite-pathogenic fungus Neozygites floridana. Predatory mites (Phytoseiidae) were recorded on both leaf types, and the females mounted and identified. We also sampled leaves from selected plants in the boundary vegetation of most fields, to look for sources of T. urticae, phytoseiids and N. floridana, and soil from each field, to study the natural occurrence of entomopathogenic nematodes. We will present the results on abundance and diversity of the organisms investigated, and discuss similarities and differences between organic and conventional fields.
Sammendrag
How traps are placed can have huge consequences for trap efficiency. We present the results from two trials on how the height of trap deployment affects the catch of new generation Anthonomus rubi. In trial 1 (September 2006) we used white sticky traps, with or without A. rubi aggregation pheromone lures, to get more information on the height distribution at which weevils fly. Traps were horizontally mounted on top of poles 1 or 3 m above ground in a commercial field with a large weevil population (4 replicates of each height and lure combination). All the A. rubi individuals caught (N=34) were found on traps placed 1 m above ground. In trial 2 (13 July - 1 September 2009), four trap heights (partly dug into the ground, standing on the ground, hung just above foliage, hung 1 m above ground) were replicated five times in a small experimental strawberry field with severe bud damage. The traps were green funnel traps enhanced with white cross-vanes developed for raspberry beetle, and the best lure combination (aggregation pheromone sachet plus strawberry flower volatile open vial) for A. rubi found in other experiments. The traps touching the ground (and the plants), i.e. the first two of the heights listed above, caught 90% of all A. rubi trapped (N=103).
Forfattere
Nina TrandemSammendrag
10 bilder av småkryp/ skadesymptomer i frukt og bær
Forfattere
Anne Kjersti Bakken Tor Lunnan Mats HøglindSammendrag
Enga må slåast ung og ofte dersom grovfôret skal ha høg potensiell næringsverdi. Ein slik intensiv haustepraksis vil ein forvente gir lågare avlingar og ei mindre varig eng i høve til ein praksis med sjeldnare og/eller seinare slåttar. Desse spørsmåla har ein sett nærare på i prosjektet "Mer og bedre grovfôr som basis for norsk kjøtt- og mjølkeproduksjon ". Ein fann moderate avlingstap med tidlege og hyppige slåttar.
Forfattere
Arnfinn Nes Muath Alsheikh Ragnhild Sween Magne GullordSammendrag
Scandinavian countries, including Norway, is in marginal areas for commercial strawberry production, but the culture is still an important hortucultral crop. There is an increasing demand for new and better cultivars for the regional conditions in the industry. The Norwegian strawberry breeding program has lasted more than 40 years and several cultivars have been released. In 2002 the National Norwegian strawberry breeding program was privatized to Graminor Breeding Ltd. The program has responsibility to supply the Norwegian market with new well-adapted and productive strawberry cultivars with high berry qualities, in order to add to the profitability of the growers. Graminor Breeding Ltd. is also representing foreign cultivars in Norway. Three new cultivars have been launched in 2007: "Gudleif", "Iris" and "Blink".
Forfattere
Eivind VangdalSammendrag
Innhaldet av fenoliske sambindingar vart målt i plommesortane Avalon, Excalibur, Jubileum, Reeves, Victoria og Valor. Den dominerande fenoliske syra var i alle sortane neoklorogensyre. Det var signifikante skilnader mellom sortane i innhaldet av fenoliske syrer. Cyanidin-3-rutinosid utgjorde meir enn 60% av det samla innhaldet av antocyanar. Mindre mengder av flavonolane rutin og quercitin vart funne i alle sortane. Total antioksiderande verknad varierte frå 814 til 290 µmol Trolox pr 100g friskvekt. Målingar av totalt fenolinnhald med metoden basert på danning av Prøyssarblå kompleks viste ei betydeleg metodisk feil samanlikna med resultat med HPLC-amalyse. Samanlikning av målingar av ei rekkje fenoliske emne med metodar basert på Prøyssiskblå og Folin-Ciocalteu-assay viste at sistnemnde gav høgare verdiar i form av gallesyre (GAE).
Sammendrag
Transport and turnover of dissolved organic carbon (DOC) is important in the C cycle of organic soils. The concentration of DOC in soil water is buffered by adsorption to the soil matrix, and has been hypothesized to depend on the pool size of adsorbed DOC. We have studied the effect of frequent artificial excessive leaching events on concentration and flux of DOC in shallow, organic rich mountain soils. Assuming a constant Kd value for DOC adsorption to the soil matrix, we used these data to assess the change in the pool of adsorbed (or potential) DOC in the soil. The study involved manipulation of precipitation amount and frequency in summer and autumn in small, heathland catchments at Storgama, southern Norway. The shallow soils (16 to 34 cm deep on average) limit the possibility for changes in water flow paths during events. The mini-catchments range in size from 75 m2 to 98 m2. Our data show that after leaching of about 1.2 g DOC m-2 the DOC concentration in runoff declines by approximately 50%. From this we conclude that the pool size of adsorbed potential DOC in the shallow soils at any time is of the order 2-3 g m-2. Frequent episodes suggest that the replenishment rate, which depends on the decomposition rate of soil organic matter, is fast and the potential DOC pool could be fully restored probably within days during summer, but with some more time required in autumn, due to lower temperatures. Both pool size of potential DOC and replenishment rate are seasonally dependent. The pool of potential DOC, and thus the DOC concentration in discharge, is at their maximum in the growing season. However, under non-leaching conditions, the concentration of DOC in soil water and thus the pool size of potential DOC seems to level off, possibly due to conversion of DOC to less reversibly bound forms, or to further decomposition to CO2.
Forfattere
Ricardo Holgado Stig Andersson Janet Rowe Ian Clark Christer MagnussonSammendrag
Norwegian cereal cyst nematode populations were studied by biochemical, molecular, morphological and bio test techniques. H. avenae occurred in the pathotypes, Ha11, Ha12, and H. avenae Våxtorp. H. filipjevi was recorded as pathotype West. H. avenae (Ha 11) and H. filipjevi West were the most common species. Thirty barley, 23 oat and 6 of summer wheat cultivars on the Norwegian market were tested for their resistance against H. avenae (Ha11), H. avenae Våxtorp and H. filipjevi West. Resistance against Ha11 was found in 5 barley, 3 oat and in 1 wheat cultivar. Resistance against H. avenae Våxtorp was not present in barley, but 4 oat and 1 wheat cultivar were resistant. For H. filipjevi West resistance was not detected in wheat, but in 6 barley and 13 oat cultivars. A management system based on careful nematode identification and knowledge on resistance of cultivars were set in operation in the county of Vestfold. As a result farmers have improved average yields by 1000 kg /ha. By implementing this program in full the county of Vestfold could make an annual gain of 800 000 €. In perspective of increasing damage from CCN world-wide the correct identification of species and the recognition of their genetic variability is instrumental for successful control.
Forfattere
Ricardo Holgado Stig Andersson Janet Rowe Ian Clark Christer MagnussonSammendrag
Norwegian cereal cyst nematode populations were studied by biochemical, molecular, morphological and bio test techniques. H. avenae occurred in the pathotypes, Ha11, Ha12, and H. avenae Våxtorp. H. filipjevi was recorded as pathotype West. H. avenae (Ha 11) and H. filipjevi West were the most common species. Thirty barley, 23 oat and 6 of summer wheat cultivars on the Norwegian market were tested for their resistance against H. avenae (Ha11), H. avenae Våxtorp and H. filipjevi West. Resistance against Ha11 was found in 5 barley, 3 oat and in 1 wheat cultivar. Resistance against H. avenae Våxtorp was not present in barley, but 4 oat and 1 wheat cultivar were resistant. For H. filipjevi West resistance was not detected in wheat, but in 6 barley and 13 oat cultivars. A management system based on careful nematode identification and knowledge on resistance of cultivars were set in operation in the county of Vestfold. As a result farmers have improved average yields by 1000 kg /ha. By implementing this program in full the county of Vestfold could make an annual gain of 800 000 €. In perspective of increasing damage from CCN world-wide the correct identification of species and the recognition of their genetic variability is instrumental for successful control.
Forfattere
Ricardo Holgado Christer MagnussonSammendrag
The Altiplano is one of the most elevated areas populated in the world. At 3 500 - 4 000 m, low temperature, and other climatic conditions impose severe limitation for vegetable production. The average temperature levels and the daily amplitudes is a function of altitude, so vegetables are mainly produced in rustic greenhouses. NGOs in the Andean region have recommended cultivation of vegetables for consume and commercialization to enhance the well being of farmers. Plant parasitic nematodes or poor management have limited the vegetable production in rustic greenhouse. The Catholic University of Bolivia has a network of rural campuses "Unidades Académicas Campesinas" (UAC) for academic and practical teaching. Bioforsk has been involved in developing and strengthening the scientific basis in Plant Nematology in UAC-Tihauanaco. Farmers in Tiahuanaco experienced decreasing vegetable yields. In 1999 soil and plant samples from potato and other Andean crops were collected from greenhouses. All samples contained plant-parasitic nematodes. Twenty-one genera of plant-parasitic nematodes were found. The most frequent were potato cyst nematodes Globodera rostochiensis and the false root-knot nematode Nacobbus sp. (54 %), followed by lesion nematodes Pratylenchus spp. spiral Helicotylenchus sp. and Tylenchus sensu lato (41 %), ring nematodes Criconemella sp. (34 %), stunt nematodes Tylenchorhynchus spp. (29 %) and root-knot nematodes Meloidogyne sp. (19 %). The study indicated that plant-parasitic nematodes have a large impact on vegetable production. The knowledge of nematode species are of fundamental importance in the design of efficient management strategies, that would allow farmers to keep nematode population densities at levels below the threshold of economic damage. Management with crop rotation and the use of cultivars with resistance are important control measures, but require detailed information on the occurrence and density of nematode species.