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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.

2008

Sammendrag

Late blight forcasting in VIPS i s presented. Validation trials have show acceptable results regarding late blight control

Sammendrag

Kjempebjørnekjeks er en fremmed art i Norge. Arten er vurdert til å utgjøre en høy risiko for annet biologisk mangfold på voksestedet og det er behov for tiltak for å unngå ytterligere spredning. Formålet med denne undersøkelsen var å fremskaffe kunnskap om effektive metoder for bekjempelse av kjempebjørnekjeks i forbindelse med etablering av grøntanlegg ved ny E16 nær Wøyen i Bærum. I tillegg var det et mål å opparbeide kunnskap om hvordan en kan redusere bestandet av kjempebjørnekjeks når jordmasser som legges i ranke under anleggsarbeidet skal tilbakeføres til veganlegget

Sammendrag

A new potato late blight forecasting model based on hourly weather date is developed based on trials with spore traps and trap plants. The model is built up of sub models for for the different steps in the epidemiological cycle, spore production, release, survival and infection. Long humid periods are suitable for spore production, at moderate humidity the process goes slower. The amount of viable attached sporangia is reduced by drought, and some spores are washed off during rain. Spores are released into the air by a drop in humidity or increased radiation, but the release is inhibited at high leaf wetness. The amount of viable released spores is strongly inhibited by solar radiation. The spore load is also reduced by precipitation and by germination. The leaf wetness duration have to sufficient for the spores to germinate and infect. The risk of blight development is a function of the amount of viable released spores and the duration of leaf wetness.

Sammendrag

The existing potato late blight forecast and decision support systems used in the Nordic countries are based on data from the 1930s and the 1950-60s on how temperature and humidity influence Phytophthora infestans epidemiology. Influence of weather conditions on sporangium production, release, viability and infection of P. infestans was investigated in Denmark, Norway and Finland using Burkard spore traps and exposure of trap plants in field plots in 2005-2007. Large amounts of sporangia were trapped after nights with long periods with high humidity. Sporangia produced in one humidity period were mainly released at the first humidity drop in the morning hours, but there were also some periods with delayed sporangium release. Local new infections occurred mainly during the morning hours when leaves were still wet. On many days sporangia did not survive until the afternoon and the results indicate that conditions for survival of sporangia and infection are major bottlenecks for the spread and development of the disease. These results have important implications for practice. Survival of sporangia and infection must be better integrated into the calculation of "risky days" in late blight forecasting systems.

Sammendrag

The existing potato late blight forecast and decision support systems used in the Nordic countries are based on data from the 1930s and the 1950-60s on how temperature and humidity influence Phytophthora infestans epidemiology. Influence of weather conditions on sporangium production, release, viability and infection of P. infestans was investigated in Denmark, Norway and Finland using Burkard spore traps and exposure of trap plants in field plots in 2005-2007. Large amounts of sporangia were trapped after nights with long periods with high humidity. Sporangia produced in one humidity period were mainly released at the first humidity drop in the morning hours, but there were also some periods with delayed sporangium release. Local new infections occurred mainly during the morning hours when leaves were still wet. On many days sporangia did not survive until the afternoon and the results indicate that conditions for survival of sporangia and infection are major bottlenecks for the spread and development of the disease. These results have important implications for practice. Survival of sporangia and infection must be better integrated into the calculation of "risky days" in late blight forecasting systems.

Sammendrag

Phytophthora infestans is an important pathogen on potato and tomato during the winter seasons in the north of Vietnam and all the year around in Lam Dong province in the south of Vietnam. Data from earlier studies of isolates of P. infestans collected in 2002-2003 showed that the P. infestans population on tomato and potato from Vietnam still consist of the "old" population. However preliminary studies of P. infestans samples from 2007 indicate that this situation has started to change. Data from aggressiveness tests of P. infestans isolates on tomato and potato showed that the majority of isolates collected from tomato could not infect potato. All tested isolates originating from potato infected both hosts. From 2005-2007, field experiments in tomato and potato using IPM strategies for controlling late blight have been carried out in Lam Dong province and in Hanoi area (north of Vietnam). In these experiments, cultivars with different levels of late blight resistance and different fungicide dosages have been tested. Simple forecasting methods and sanitation procedures were also included in some of the experiments. In Lam Dong, strategies including 7 days fixed spray intervals with full dose of the fungicide mancozeb did not control late blight properly in tomato, and all 4 tomato experiments were terminated early. In the potato experiments use of a more modern fungicide could control late blight using reduced dosages. In the tomato experiments in the north no natural infection of late blight occurred during the experimental period.

Sammendrag

Phytophthora infestans is an important pathogen on potato and tomato during the winter seasons in the north of Vietnam and all the year around in Lam Dong province in the south of Vietnam. Data from earlier studies of isolates of P. infestans collected in 2002-2003 showed that the P. infestans population on tomato and potato from Vietnam still consist of the "old" population. However preliminary studies of P. infestans samples from 2007 indicate that this situation has started to change. Data from aggressiveness tests of P. infestans isolates on tomato and potato showed that the majority of isolates collected from tomato could not infect potato. All tested isolates originating from potato infected both hosts. From 2005-2007, field experiments in tomato and potato using IPM strategies for controlling late blight have been carried out in Lam Dong province and in Hanoi area (north of Vietnam). In these experiments, cultivars with different levels of late blight resistance and different fungicide dosages have been tested. Simple forecasting methods and sanitation procedures were also included in some of the experiments. In Lam Dong, strategies including 7 days fixed spray intervals with full dose of the fungicide mancozeb did not control late blight properly in tomato, and all 4 tomato experiments were terminated early. In the potato experiments use of a more modern fungicide could control late blight using reduced dosages. In the tomato experiments in the north no natural infection of late blight occurred during the experimental period.