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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.

2010

Sammendrag

Estimates of ascospore maturity generated by models developed for Venturia pirina in Victoria, Australia (V-NV, V-SV), Oregon, USA (S), or for Venturia inaequalis in New Hampshire, USA (NH-1 and NH-2) were compared to observed ascospore release of V. pirina in 21 site/yr combinations. When plotted against degree-days, the lag phase and slope of all model estimates differed from observed release. The S model and V-SV model fit well with the data from Southern Victoria, while the data from Norway, Belgium and most years from Northern Victoria show a lag phase in the beginning of the season that was not present in the two models. In particular, data from the high-rainfall region of southern Victoria showed more variation between years than the other sites. Identifying the precise biofix (bud break) to initiate degree-day accumulation for the NH-2 model was problematic at both Australian sites, as regions with warm winters and minimal chilling exhibit protracted bud break. Linear regressions generated similar R2 values for the various models in many cases, but where differences were noted they more often favored the most recent model developed for V. inaequalis (NH-2). The NH-2 model also provided the most accurate estimates of 95% ascospore depletion (a key event in many disease management programs) for Norway, Belgium, and the higher rainfall areas of southern Victoria. Although developed for use in management of apple scab, the NH-2 model appears a reasonably accurate tool for predicting the release of ascospores by the pear scab pathogen, in particular in regions with moderate rainfall and colder winters.

Sammendrag

Two female and two male cultivars have previously been released as a result of clone evaluation at Bioforsk Nord Holt. Selection criteria have been number of pistils or stamens per flower, number of flowers and number of shoots per m2. Currently a new group of clones are evaluated with the aim of finding new cultivars for release. The clones are collected from different parts of Norway, as well as from England and Spitsbergen. Preliminary results from harvesting 2005, 2006, 2007 and 2008 indicate good production potential for some of the tested clones. In addition to prior selection criteria based on berry yield, the levels of total anthocyanins and total phenols have been analyzed. This includes studies on the role of female clone, male pollinator and temperature on berry quality.

Sammendrag

The plant growth regulator trinexapac-ethyl (TE) has been evaluated in five registration trials in Finland and Norway. In 2007, TE was applied monthly at rates 0.023-0.090 kg a.i. ha-1 in a creeping bentgrass green trial and 0.057-0.339 kg a.i. ha-1 in two bluegrass/fescue fairway trials. Seasonal clipping yield reductions varied from 8 to 21 % in the green trial and from 0 to 25 % in the fairway trials; reductions were usually significant at two, but not at four weeks after application. Phytotoxic effects were observed at rates ≥ 0.113 kg a.i. ha-1 in one of the fairway trials, but TE resulted in less snow mould and faster green-up in 2008 in the other fairway trial and in the green trial. In a new green trial established 2008, weekly or biweekly applications of TE at rates 0.017-0.051 kg a.i. ha-1 reduced clippings by an average of 25 % and increased ball roll distance by an average of 6 %, however,  differences among sprayed plots were not significant. In conclusion, we recommend that TE be approved for use on Scandinavian golf courses. Recommeded rates and application intervals are 0.023-0.046 kg a.i. ha-1 every 1-2 weeks on greens and 0.057-0.113 kg a.i. ha-1 every 2-3 weeks on fairways. The lower rates must always be used at the first application.

Sammendrag

The plant growth regulator trinexapac-ethyl (TE) has been evaluated in five registration trials in Finland and Norway. In 2007, TE was applied monthly at rates 0.023-0.090 kg a.i. ha-1 in a creeping bentgrass green trial and 0.057-0.339 kg a.i. ha-1 in two bluegrass/fescue fairway trials. Seasonal clipping yield reductions varied from 8 to 21 % in the green trial and from 0 to 25 % in the fairway trials; reductions were usually significant at two, but not at four weeks after application. Phytotoxic effects were observed at rates ≥ 0.113 kg a.i. ha-1 in one of the fairway trials, but TE resulted in less snow mould and faster green-up in 2008 in the other fairway trial and in the green trial. In a new green trial established 2008, weekly or biweekly applications of TE at rates 0.017-0.051 kg a.i. ha-1 reduced clippings by an average of 25 % and increased ball roll distance by an average of 6 %, however,  differences among sprayed plots were not significant. In conclusion, we recommend that TE be approved for use on Scandinavian golf courses. Recommeded rates and application intervals are 0.023-0.046 kg a.i. ha-1 every 1-2 weeks on greens and 0.057-0.113 kg a.i. ha-1 every 2-3 weeks on fairways. The lower rates must always be used at the first application.