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.
2011
Forfattere
Nina Trandem Sverre Kobro Geir Kjølberg Knudsen Eivind Vangdal Endre Bjotveit Sigrid MoganSammendrag
Artikkelen går gjennom middelprøving og dyrkererfaringer med angrepsnivået i 2010 og preparatet Coragen, som ble brukt på dispensasjon. Merk at figur 2 og 3 har fått byttet om teksten, riktig kombinasjon av figurer og figurtekst er trykket i påfølgende nummer av Norsk Frukt og Bær (nr 3 2011)
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Verden over er det store økonomisk og avlingstap på grunn av plantesjukdommer som følger plantemateriale hvert år. I Norge har vi et godt etablert fremavlssystem, et systematisk arbeid for å fremskaffe friskt plantemateriale av vegetativt formerte vekster. Målet er å produsere sortsriktig plantemateriale som er friskt og som derfor har fullt potensiale til å gi optimal avling og kvalitet. Kryoteknologien, en veletablert teknologi, har potensiale til å effektivsere dette arbeidet, både med hensyn på rensing og oppbevaring av plantemateriale.
Sammendrag
The use of Chinese cabbage as a trap crop where insect pathogenic fungi may prolifereate has been tested in a series of push-pull strategy experiments both in the laboratory and in the field. The pest species studied are the cabbage- and turnip root fly (Delia radicum and D. floralis). In a dual choice laboratory experiment, both healthy and Entomophthora muscae inoculated D. floralis were tested for choice of plant for oviposition. The choices were 1) Broccoli against Broccoli 2) Chinese cabbage against Broccoli 3) Broccoli against Broccoli under sown with clover 4) Chinese cabbage against Broccoli under sown with clover. In a semi-field pilot study with Broccoli and Chinese cabbage the choice between main - and trap crop for healthy and inoculated flies, as well as fungal transmission between flies over time, was studied. A pilot field study has also been performed to investigate the overall effect of using Chinese cabbage as a trap crop as well as studying the spatial distribution of Delia eggs in a cabbage field. The results from the dual choice experiment and both pilot studies indicates that using Chinese cabbage as a trap crop is a promising strategy for the management of D. radicum and D. floralis, both as a oviposition attractant and as a trap crop where insect pathogenic fungi may proliferate and kill the adult flies.
Forfattere
Jr. I Delalibera V.W. Wekesa Karin Westrum V. Duarte da Silveira T. Rodrigues de Castro S.S. Nilsen Ingeborg KlingenSammendrag
The mite-pathogenic fungus Neozygites floridana and N. tanajoae are important natural enemies of spider mites and are good candidates for microbial control. To be able to succeed in using Neozygites for the microbial control of spider mites we need to understand the factors that affect a Neozygites epidemic development. Studies have therefore been conducted with Brazilian and Norwegian isolates of these fungi to reveal the effect of abiotic (temperature, rainfall, humidity, light, pesticides) and biotic factors (host plant, presence of predators) on the fungal performance and epizootic development in cassava green mite, tomato red spider mite and twospotted spider mite populations. For Brazilian isolates, rainfalls do not seem to have an apparent impact on disease progression. Microclimatic humidity seems, however, to be a critical factor. When placed on microscope slides, these two fungi only sporulate at RH≥95%, while N. floridana-killed cadavers of the twospotted spider mite placed within the boundary layer of the abaxial side of a leaf sporulated also at 90% RH. The temperature optimum of Brazilian and Norwegian isolates varies and Brazilian isolates can sporulate at temperatures as low as 13°C but the highest production of capilliconidia occurs at 21-25°C. A Norwegian N. floridana isolate tested produces the highest numbers of primary conidia at 13°C and 18°C while 23°C resulted in a lower production. Our studies also show that performance of different N. floridana isolates may vary with light duration and intensity. In integrated pest management systems, Neozygites needs to be compatible with chemical pesticides. Our studies show, however, that several fungicides affect N. floridana negatively. Our studies have also shown that performance of Neozygites vary with host plants.
Sammendrag
The two spotted spider mite Tetranychus urticae is known to overwinter as hibernating females, and these partly inactive females may harbour Neozygites floridana. N. floridana is a fungal natural enemy of spider mites. The aim of this study was therefore to investigate whether N. floridana may be present inside living hibernating females of T. urticae throughout the winter season, and if so, in what prevalence and what stage of its fungal life cycle. Hibernating T. urticae females were investigated for the presence of fungal structures throughout one winter (October 12, 2006 to February 19, 2007) in field-grown strawberries in a cold climate in Norway (min. ambient temp -15.3oC). The study confirmed that N. floridana survived the winter as a semilatent hyphal body infection, protected inside live hibernating females. The beneficial fungus N. floridana is therefore ready to develop and sporulate as soon as climatic conditions permits, resulting in early season infection of T. urticae. An early-season infection of N. floridana that may result in the control of T. urticae in strawberries is important, since T. urticae is known to cause reductions in strawberry yield at much lower population levels in early season than in late season. For N. floridana to control T. urticae populations early in the spring, factors important for sporulation and dissemination of the fungus needs to be favoured. The adapted use of pesticides, especially fungicides might therefore be very important at this time of the year.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Annette Folkedal Schjøll Ingeborg Klingen Maria Bjørkman Pierre Antoine Allard Idun Bratberg Richard MeadowSammendrag
A successful push-pull strategy needs to include means to kill pest insects in order to control and reduce the pest population. The use of Chinese cabbage as a trap crop where insect pathogenic fungi may proliferate has been tested in a series of push-pull strategy experiments both in the laboratory, in semi-field and field. In this work, the aim is to develop a push-pull-kill strategy in which the transmission of the entomopathogenic fungi Entomophthora muscae is facilitated with the aim to reduce the population of cabbage- and turnip root flies (Delia radicum and Delia floralis). In the lab experiment, Chinese cabbage proved to be more attractive compared to Broccoli and Broccoli undersown with red clover, for oviposition of both healthy and E. muscae infected D. floralis females. Infected flies also died and sporulated on or near the Chinese cabbage. This pattern was also evident in a preliminary field study in which sporulating Delia spp. cadavers were found on Chinese cabbage only. These results indicate that Chinese cabbage may be used as a trap crop for D. floralis oviposition, but it may also be a sink where healthy flies become infected through contact with sporulating cadavers. This summer, we tested the strategy in larger scale and under more natural conditions in a semi-field study. Healthy D. floralis were released in cages with Broccoli and Chinese cabbage plants, with or without the presence of E. muscae infected D. radicum. Our hypothesis were that 1) D. floralis released in cages with infected flies will be infected, and die and sporulate on or near the Chinese cabbage, 2) Fewer eggs will be laid by D. floralis in cages with infection compared to control cages, 3) More D. floralis eggs will be laid on Chinese cabbage compared to Broccoli. The results from the semi field study strenghtens our previous results which showed that using Chinese cabbage as a trap crop is a promising strategy for the management of D. floralis and D. radicum, both as an oviposition attractant and as a source for fungal transmission between flies.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag