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.
2009
Sammendrag
Det er en vanlig oppfatning blant bærdyrkere at relativt lav høst-temperatur er gunstig for rik blomsterdanning hos jordbær og bringebær. I ei tid med klimaendringer, er det derfor mange som spør om hvordan de milde høstene vi har hatt i det siste, påvirker blomstring og avling. Vi har i de seinere åra studert blomstring hos arter og sorter av jordbær og bringebær under kontrollerte klimaforhold, og kan nå langt på vei forklare fysiologiske særtrekk for blomstringen hos disse artene, og derigjennom peke på fordeler og begrensninger for dyrkingen under endrede temperaturforhold. Hovedkonklusjonen blir, at mens mildere høster vil være en fordel for blomsterdanningen hos våre vanlige jordbærsorter, og for høstbærende bringebær, vil dette virke negativt og føre til seinere blomsterdanning hos to-årige bringebærsorter.
Sammendrag
1) Tilførsel av N til ulik tid i forhold til blomsterdifferensiering/ kort dag2) Tidspunkt for blomsterdifferensiering i jordbær på friland
Sammendrag
This paper describes briefly the phenomena of alternate bearing of European plums and point out that more detailed investigations about physiological factors, in particular plant hormones, involved in the flowering process are of great importance.
Sammendrag
Fruit samples of seven sweet cherry cultivars grouped into three different groups of fruit flesh firmness (soft-fruited: 'Ranna Ljaskovska', 'Vista' and 'Sunburst', medium firm: 'Ulster' and 'Sylvia' and firm cultivars: 'Van' and 'Lapins') were harvested over a three week period with 3-4 d intervals prior to, during and after normal harvest time in 1997 and 1998 in Ullensvang, western Norway. Fruit firmness was measured at each harvest date along with measurements of soluble solids content (SSC), air temperature, precipitation and estimation of fruit colour. Corresponding samples picked at normal harvest date were stored in normal air atmosphere at temperatures 2 degrees C and 8 degrees C, respectively, and firmness was measured during storage with 3-5 d intervals. All the tested cultivars reached normal firmness, colour and SSC at harvest both years. Fruit were generally darker in 1998 than in 1997. All cultivars showed a more or less distinct reduction in firmness over the period prior to and slightly after normal harvest. Exceptions were 'Sunburst' in the 1998-season, that increased in firmness after normal harvest date, and the two firmest cultivars that increased in firmness over the ripening period in 1997. Generally, firmness increased during the first part of storage followed by a decrease after 1-2 weeks, the decrease being usually earlier and more distinct at 8 degrees C than at 2 degrees C. 'Van' in 1998 showed no change in firmness development throughout the storage period but a small increase in the last part. 'Lapins' in 1997 had however, a pronounced drop in firmness in the middle of the storage period followed by an increase. All the tested cultivars were more firm at normal harvest time in 1998 than in 1997, except the two firm-fleshed cultivars 'Van' and 'Lapins'. The warm and sunny 1997-summer produced softer fruits than the cold and rainy 1998-season, except for the firm-fleshed cultivars. It was anticipated that the many contradictory results of sweet cherry fruit firmness reported by other authors may be caused by differences in weather conditions as demonstrated.
Forfattere
Mekjell MelandSammendrag
‘Elstar" is the latest-maturing commercial apple cultivar grown in Norway, with high fruit quality when properly managed. In May 2006, an experiment with four different crop loads [2, 4 ,6, or 8 flowers or fruitlets cm-2 trunk crosssectional area (TCSA), respectively] was established at two different stages [first bloom (FB), or 20-mm diameter fruitlets] and compared to unthinned control trees. Fruit growth was measured on individual fruit for each treatment throughout the season at weekly intervals. Thinning at FB gave a significantly lower final percentage fruit set than thinning to the same cropping level at the 20-mm fruitlet stage. However, fruit weights and soluble solids contents (SSC) were significantly higher, and the background fruit colour improved when trees were thinned at FB. The final number of fruit at harvest was less than the amount established at FB, or at the 20-mm fruitlet stage. There were significant differences between treatments in final fruit numbers per TCSA, which reflected the different crop loads. Fruit weights and SSC values were highest with the lowest crop load, and decreased with increasing crop loads.There was also a strong crop-load effect on the extent of return bloom per tree in the subsequent year. Trees thinned at FB had significantly more flower clusters than those thinned at the 20-mm fruitlet stage of. Untreated control trees had the lowest number of flower clusters. The amount of return bloom declined with increasing crop load. Second year crop loads and fruit weights were highest when trees were thinned at FB to two or four apples cm-2 TCSA in the previous year. Trees with the highest crop load had the lowest crop load in the following year. Fruit quality was generally high for all treatments.
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.
Forfattere
Mekjell MelandSammendrag
Det er ikke registrert sammendrag
Forfattere
Mekjell MelandSammendrag
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
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
Det er ikke registrert sammendrag