Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2017
Abstract
The aim of this study was to evaluate the natural occurrence of Beauveria spp. in soil, from infections in the stink bug Piezodorus guildinii, an important pest of common bean (Phaseolus vulgaris) and as endophytes in bean plant tissue. Twelve conventional and 12 organic common bean fields in the Villa Clara province, Cuba were sampled from September 2014 to April 2015. One hundred and fifty Beauveria isolates were obtained from soil samples, bean plant parts and stink bugs. The overall frequency of occurrence of Beauveria isolates in conventional fields (8.4%) was significantly lower than that in organic fields (23.6%). Beauveria were also obtained significantly more frequently from bean roots in organic fields (15.0%) compared to bean roots in conventional fields (3.3%). DNA sequencing of the intergenic Bloc region was performed for Beauveria species identification. All isolates where characterized as Beauveria bassiana (Balsamo-Crivelli) Vuillemin, and clustered with isolates of neotropical origin previously described as AFNEO_1. The Cuban B. bassiana isolates formed five clusters in the phylogeny. Isolates of two clusters originated from all four locations, organic and conventional fields, as well as soil, plants and stink bugs. Organic fields contained isolates of all five clusters while conventional fields only harbored isolates of the two most frequent ones. Mating type PCR assays revealed that mating type distribution was skewed, with MAT1/MAT2 proportion of 146/4, indicating limited potential for recombination. The present study is the first to report of B. bassiana as a naturally occurring endophyte in common bean. Further, it shows that B. bassiana occurs naturally in diverse environments of common bean fields, and constitutes a potential reservoir of natural enemies against pest insects particularly in organic fields.
Authors
Ingunn M. VågenAbstract
No abstract has been registered
Authors
Nick Hutchings Isabelle Weindl C. F. E. Topp V. O. Snow A. Rotz H Raynal Şeyda Özkan Gülzari R Martin D. P. Holzworth A.-I. Graux P. Faverdin Agustin del Prado Richard Eckard André BanninkAbstract
No abstract has been registered
Authors
Gregory TaffAbstract
No abstract has been registered
Abstract
Application of fish sludge as fertiliser to agricultural land can contribute to closing nutrient cycles in fish farming. The effect of different treatment technologies on the nitrogen fertilisation effects of fish sludge was studied by a bioassay with barley (Hordeum vulgare), an incubation and a field experiment. Dried fish sludge resulted in relative agronomic efficiency of 50–80% compared with mineral fertiliser. The anaerobic digestate based on fish sludge (20 vol%) and dairy manure did not increase nitrogen uptake in barley. Increasing the ratio of fish sludge in the digestate increased the fertilisation effect, but requires optimisation of the biogas process. A simple logistics analysis conducted for a case hatchery showed that on-site drying and co-digestion of fish sludge in a central biogas plant can be regarded as equal in terms of costs. Norway can become an exporter of fish sludge-based recycling fertilisers if current regulations are modified to facilitate nutrient recycling.
Authors
Milan Lstibůrek Yousri A. El-Kassaby Tore Skrøppa Gary R. Hodge Jørn Henrik Sønstebø Arne SteffenremAbstract
No abstract has been registered
Authors
Sigmund Hågvar Ronny Steen Daniel FløAbstract
Nine species of carabid beetles (Coleoptera, Carabidae) were pitfall-trapped during two years in an alpine glacier foreland of southern Norway. A two-year (biennial) life cycle was documented for Nebria nivalis (Paykull, 1790), N. rufescens (Ström, 1768), and Patrobus septentrionis Dejean, 1828. This was based on the simultaneous hibernation of larvae and adults. In P. septentrionis, both larvae and adults showed a considerable activity beneath snow. A limited larval material of Amara alpina (Paykull, 1790) and A. quenseli (Schönherr, 1806) from the snow-free period indicated larval hibernation. A. quenseli was, however, not synchronized with respect to developmental stages, and its life cycle was difficult to interpret. Measurements of claw lengths in eight species showed a considerable wearing during adult life. The data indicated that some individuals might hibernate a second time and thus experience two egg-laying seasons. Wearing of mandible tooth was not suited as age indictor in Nebria nivalis and N. rufescens, since some individuals hatched with a small tooth. Supplied with literature data, a “niche profile” is presented for each species. The most important ecological factors that contributed to niche segregation were: preference for vegetation-free ground, occurrence along the successional and time gradient, humidity or temperature preference, nocturnal versus diurnal activity, flight ability, food habits, phenology, and the ability to be active under snow.
Authors
Christian PedersenAbstract
No abstract has been registered
Authors
Anna Birgitte MilfordAbstract
No abstract has been registered
Abstract
No abstract has been registered