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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.

2009

Sammendrag

Rain-induced fruit cracking in sweet cherries can be a major problem. In the Pacific Northwest, due to high labor costs, when fruit cracking exceeds 25% at harvest, fruit are not picked. OSU Horticulture and Pharmacy Faculty have collaborated in producing and patenting a novel, elastic, organic biofilm, SureSeal, which significantly reduced sweet cherry fruit cracking by up to 250% in Milton Freewater, Oregon and Loftus, Norway. Formulations of SureSeal are hydrophobic and consists of a copolymer of complex carbohydrates, phospholipids and calcium. Collaborative research undertaken over three years throughout the Pacific Northwest and overseas found that two applications of 1% SureSeal applied at straw color and again ten days later, reduced fruit cracking consistently when compared to untreated control fruit. Indeed, in Norway, fruit cracking was reduced from 24.6% to 9.8% when trees were treated with SureSeal in combination with plastic ground covers and a preharvest fungicide (fenhexamid). Furthermore, all these studies throughout Oregon and Idaho, found that SureSeal resulted in significantly (P

Sammendrag

The performance of  26 different cherry rootstocks (‘Hexaploid Colt"," Damil",  ‘Tabel® Edabriz", ‘Gisela® (Gi) 3", ‘4", ‘5", ‘6", ‘7", ‘11", ‘Giessen (GI) 107/1", ‘148/13", ‘154/7" , ‘195/20", ‘318/17", ‘497/8", ‘523/02", ‘Weiroot (W) 10", ‘53", ‘158", ‘Maxma 14", ‘Maxma 60", ‘Maxma 97", ‘PHL-A", ‘PHL-B", ‘Piku®1"and ‘Piku® 3"), compared with ‘Colt" as a standard, for the cultivar ‘Lapins" (Prunus avium L), was assessed in a field trial in western Norway at 60° North. Trees, one-year-old whips, were planted in spring 1999; at 2.0 x 4.5 m spacing and trained to central leader as free spindle. Tree vigour, yield, fruit size, fruit quality and yield efficiency were evaluated for eight subsequent years. Tree sizes were significantly affected by the rootstocks after eight years growth. ‘Tabel®Edabriz", ‘Gi 3" and ‘Gi 4" produced the smallest and ‘Piku®3", ‘Colt"," Damil" and ‘Maxma 60" the largest trees as measured by trunk cross-sectional area (TCSA).  The most vigourus rootstock had five times larger TCSA than the dwarfest rootstocks. ‘Piku®1" was the most productive rootstock for this cultivar with highest cumulative yield followed by ‘Colt", ‘Piku®3" and ‘Gi 523/02". Average yield per tree and per year during the first seven cropping  years was 12 kg for ‘Piku®1". ‘Piku®1" and ‘Gi 5" induced early bearing.  Trees on ‘Gi 5" and ‘Gi 6"were the most yield efficient. Fruit size became significantly affected by the different rootstocks. In average for the different cropping years many of the Gi number selections, ‘Colt", ‘Damil" and ‘Piku®1"all  had a average fruit weight larger than 10 g per fruit. Fruit quality characterized by the content of soluble solids was in an average of 17.5 %. It was not influenced by crop load and did not differ much between trees on the various rootstocks. In conclusion, for high density production systems the most productive semi-vigorous rootstocks were ‘Colt"," Piku®3" and ‘Damil" and the semi-dwarf  Piku®1", ‘Gi 5" and "Gi 6". 

Sammendrag

The European plum cultivar ‘Jubileum" blossoms abundantly most years and too many flowers can be set if not properly thinned.  For two seasons started in 2007 mature ‘Jubileum/St. Julien A  were treated with ethephon when full bloom opened at concentration of 250, 375 and 500 ppm and at 10-12 mm fruitlets stage at concentration of 125, 250 and 375 ppm. The experimental design was completely randomised with 6 replications of single trees. The trees were sprayed to run-off with a hand sprayer when temperature was above 15 ºC. All thinning treatments reduced the fruit set significantly.  The fruit set decreased with increasing ethephon concentration, and the highest rates at bloom and fruitlet overthinned. Less dosage of ethephon was required at fruitlet time in order to obtain the same fruit set. The yield did confirm the fruit set response and the yield reductions were significant. All thinning treatments gave higher percentage of fruits  larger than 38 mm fruit size compared to the unthinned control. Fruit quality characterized by  blue surface cover and the content of soluble solids was in general high and  increased significantly by reduced fruit. Fruit firmness, however, slightly declined in the ethephon thinned trees. Other fruit quality parameter like percentage acid content did not show a clear response to the thinning. Return bloom was little improved on thinned trees the following year. The crop load per tree was reduced to about the half of the previous year control trees included. In conclusion,  ethephon application at a rate of 375 ppm applied at full bloom or 250 ppm  at 10 mm fruit  diameter thinned ‘Jubileum" plums to a target of about 10 -15 % fruit set.    

Sammendrag

Intensive sweet cherry production (Prunus avium L.) in tunnel covered orchard systems offer an advantage of reducing rain-induced fruit cracking and other secondary advantages such as manipulation with the environment and fruiting. The research  objective is to develop a management system to delay fruit maturity in sweet cherry trees for producing late season, high quality fruits for the export market. In May 2005 a Haygrove multibay tunnel system was installed at the experimental farm at Bioforsk Ullensvang, Norway. It consisted of four bays (8.5 m width and 70 m long each). It was built on 2.5 m legs and has an open kit strut system fully accessible for tractor.  In these tunnels feathered 1-year old sweet cherry ‘Sweetheart"/Colt trees were planted; two rows in each tunnel. Trees were planted in four-tree plots with ‘Lapins" as guard tree in between and trained as free spindles. Planting distance was 2.0 x 4 m.  Each tunnel was splitted into two halves covered with plastic covers having different light spectral transmittance; Luminance THB film (absorbing infrared light) and traditional Visqueen clear UV polythene film.  Two tunnels were covered before bloom by the end of April and two tunnels in early July. Subplots consisted of treating with 20 ppm gibberellin at straw yellow fruit colour and of reflective ground cover. Documentation of the environmental modifications, evaluation of tree growth, reproductive performance and impact of pests will be studied. The harvest on the control trees started in mid August. Preliminary results showed that GA3 treated trees delayed the harvest with about a week, improved fruit size and fruit firmness.  Average crop per tree was 9 kg in the fourth leaf. Size distribution of the fruits showed that half of the fruits were in average larger than 32 mm in diameter. The polythene film Luminance THB reduced the temperature build up on sunny days and improved the fruit size.