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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.

2016

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The cyanomorph and photosymbiodemes are here reported for the first time for Ricasolia virens (With.) H.H. Blom & Tønsberg comb. nov. (≡ Lobaria virens (With.) J.R. Laundon). The cyanomorph of R. virens is dendriscocauloid. The observed early developmental stages involve (1) a free-living cyanomorph and (2) a photosymbiodeme composed of the cyanomorph supporting small, foliose, chloromorphic lobes. Whereas the chloromorph continues to grow, the cyanomorph decays and disappears leading to the final stage (3), the free-living chloromorph. Secondary cyanomorphs emerging from the chloromorph are not known.

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The root-knot nematode Meloidogyne graminicola is a major constraint in rice production in the world. Using rDNA-ITS sequences data alignments, the genetic variation among twenty-one populations of M. graminicola (sixteen from Myanmar and five from China) was investigated. The results showed that all the populations were clearly separated from other species and that there was a low level of genetic variation among the isolates. A set of species-specific primers was designed to develop a species-specific molecular tool for the precise identification of M. graminicola. The primer reliability, specificity and sensitivity tests showed that the primer set (Mg-F3 and Mg-R2) amplified the expected fragment size of 369 bp from the template DNA of target nematode populations but not from non-target organisms. A duplex PCR test allows for saving diagnostic time and costs by amplifying the species of interest from a nematode mixture. Therefore, this species-specific primer set may be a powerful tool to improve taxonomic identification by non-specialists and the design of successful management practices as well.

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The study examines the economics of different calf rearing systems and considers effects of suckling and milk feeding on production, health and welfare of dairy cows and growth, milk and feed use, health and welfare of calves. The economics of (i) no suckling, (ii) suckling for 3 days, (iii) suckling for 7 weeks, all assuming milk or milk replacer fed until weaning at 13 weeks, was compared with (iv) suckling for 13 weeks and no milk feeding. A linear programming (LP) model, maximizing profit on a dual purpose dairy-beef farm in lowland eastern Norway, was used for the comparison. Details on calf rearing methods, labor, weaning age, intake of milk, and solid feed were gathered for a sample of organic farms and grouped according to the length of the suckling period. The data were coupled with the National Dairy Herd Recording System (NDHRS) using cross-sectional data for the years 2008–2013. The results of the model study showed that suck- ling up to at least 7 weeks and longer than on most farms in the survey, had a positive influence on the farm economics. This was due to the positive influence on calf growth and health as well as lowered costs. Consequently, dual purpose dairy-beef farmers should be careful to sacrifice calf suckling and restrict calf milk feeding. Long suckling until weaning at 13 weeks was, however, unprofitable.

Sammendrag

The effects of cutting frequency, silage fermentation pattern and legume performance in grass-clover ley on use of inputs and profitability in an organic dairy system in Mid-Norway were examined. A whole-farm linear programming model was developed to compare a three-cut and a two-cut system, either with restricted silage fermentation through acidification or untreated at low or high red clover (Trifolium pratense L) proportion in the ley. Input-output relations incorporated into the model were derived from a meta-analysis of organic grassland field trials in Norway, silage fermentation experiments, and with feed intakes and milk yields from simulations with the NorFor feed evaluation system. The model maximised total gross margin of farms with 250,000 l milk quota, and housing capacity for 45 cows. Farmland availability was allowed to vary with 40 ha as the basis. High proportion of legumes in the leys was far more important for profitability than the score on the other variables considered. With little land available, the costs of preservatives were higher than their benefits. At higher land areas applying preservatives was more profitable. Cutting systems producing silages that result in an increased intake of silage per cow, generally three-cut systems, performed relatively better at higher land availabilities.

Sammendrag

The effects of cutting frequency, silage fermentation pattern and legume performance in grass-clover ley on use of inputs and profitability in an organic dairy system in Mid-Norway were examined. A whole-farm linear programming model was developed to compare a three-cut and a two-cut system, either with restricted silage fermentation through acidification or untreated at low or high red clover (Trifolium pratense L) proportion in the ley. Input-output relations incorporated into the model were derived from a meta-analysis of organic grassland field trials in Norway, silage fermentation experiments, and with feed intakes and milk yields from simulations with the NorFor feed evaluation system. The model maximised total gross margin of farms with 250,000 l milk quota, and housing capacity for 45 cows. Farmland availability was allowed to vary with 40 ha as the basis. High proportion of legumes in the leys was far more important for profitability than the score on the other variables considered. With little land available, the costs of preservatives were higher than their benefits. At higher land areas applying preservatives was more profitable. Cutting systems producing silages that result in an increased intake of silage per cow, generally three-cut systems, performed relatively better at higher land availabilities.

Sammendrag

Climate, available resources and disturbance by agricultural land use influence ecosystem service (ES) delivery. In our project we studied how ES provision from managed and abandoned semi-natural grasslands vary along soil and climatic gradients. Information on climate (temperature and precipitation) and soil (pH-value and phosphorous content) were used to test whether ES varied along these environmental gradients. 13 ES indicators were calculated and assigned to nine ES. Some of the ES varied along the gradients, but the results indicate that the effects of soil and climate on ES are modified by agricultural land use.

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Background. The beneficial fungus Neozygites floridana kills the two-spotted spider mite Tetranychus urticae, which is a serious polyphagous plant pest worldwide. Outbreaks of spider mites in strawberry and soybean have been associated with pesticide applications. Pesticides may affect N. floridana and consequently the natural control of T. urticae. N. floridana is a fungus difficult to grow in artificial media, and for this reason, very few studies have been conducted with this fungus, especially regarding the impact of pesticides. The aim of this study was to conduct a laboratory experiment to evaluate the effect of pesticides used in strawberry and soybean crops on N. floridana. Results. Among the pesticides used in strawberry, the fungicides sulfur and cyprodinil + fludioxonil completely inhibited both the sporulation and conidial germination of N. floridana. The fungicide fluazinam affected N. floridana drastically. The application of the fungicide tebuconazole and the insecticides fenpropathrin and abamectin resulted in a less pronounced negative effect on N. floridana. Except for epoxiconazole and cyproconazole, all tested fungicides used in soybean resulted in a complete inhibition of N. floridana. Among the three insecticides used in soybean, lambda-cyhalothrin and deltamethrin resulted in a significant inhibition of N. floridana. Conclusion. The insecticides/ acaricides abamectin and lambda-cyhalothrin at half concentrations and fenpropathrin and permethrin and the fungicide tebuconazole at the recommended concentrations resulted in the lowest impact on N. floridana. The fungicides with the active ingredients sulfur, cyprodinil + fludioxonil, azoxystrobin, azoxystrobin + cyproconazole, trifloxystrobin + tebuconazole and pyraclostrobin + epoxiconazole negatively affected N. floridana. © 2015 Society of Chemical Industry