Oddmund Frøynes

Rådgiver

(+47) 959 06 027
oddmund.froynes@nibio.no

Sted
Ullensvang

Besøksadresse
NIBIO Ullensvang, 5781 Lofthus

Sammendrag

European plum cultivars (Prunus domestica L.) are hexaploid and partially self-fertile or self-sterile requiring compatible pollinizers with overlapping bloom times. Therefore, inter-planting ofdifferentpollinizercultivarsisrecommended. Inordertoidentifysuccessfulpollinizersoftheplum cultivars ‘Edda’, ‘Opal’ (self-fertile), ‘Jubileum’, ‘Reeves’, ‘Mallard’, ‘Avalon’, ‘Cacanska Lepotica’ (self-fertile), and ‘Valor’, 60 fruits per cultivar were collected from nine orchards in 2017 and 2018, all of which were located in Ullensvang, western Norway. DNA extraction was subsequently conducted from the obtained embryos, followed by genetic characterization using seven microsatellite markers. Tissue samples from all possible pollinizers were collected during the summer of 2017 and the same DNAapproachwasconducted. Resultsshowedthat‘Opal’wasthemostsuccessfulpollinizeramong the investigated plum cultivars. The main exception was ‘Cacanska Lepotica’, which consistently displayed very high level of self-pollination. The most successful foreign pollinizer of ‘Opal’ was ‘Mallard’. However, in more than two thirds of embryos extracted from ‘Opal’ fruits self-fertilization was determined. ‘Reeves’ was identified as the most successful pollinizer among embryos collected from ‘Valor’. Among the five cultivars (‘Edda’, ‘Jubileum’, ‘Reeves’, ‘Mallard’, and ‘Avalon’) that did not display self-pollination, the pollinizer success rate of ‘Opal’, ranged from 36.5% (‘Mallard’) to 93.5%(‘Edda’)in2017,whilein2018thisraterangedfrom43.5%(‘Jubileum’and‘Reeves’)upto96.5% (‘Edda’). Overall, genotyping embryos using SSRs (simple sequence repeats) proved an effective method in determining the success rate of individual pollinizers among European plum cultivars.

Til dokument

Sammendrag

In order to identify successful pollinizers of plum cultivars ‘Edda’ and ‘Opal’, 60 mature open pollinated fruit were collected from these two cultivars in autumn 2017. The fruits were harvested in three different orchards located in Ullensvang, the main fruit production area in Norway. After the harvest, kernels were separated from the fruit and used for the extraction of single embryos located within each kernel. At the same time, leaves were collected from the plum cultivars ‘Edda’ and ‘Opal’, as well as from all other plum cultivars present at the location and nearby orchards (‘Mallard’, ‘Jubileum’, ‘Reeves’, ‘Avalon’, ‘Valor’, ‘Cacanska Lepotica’ and ‘Herman’). DNA extraction was carried out for the embryos and leaves, and were used for genotyping using seven microsatellite markers. The microsatellite data were used for conducting paternity analyses based on a log likelihood ratio, where the fingerprint information from the leaves were the possible pollen donors available at the location. The results revealed within all examined orchards that the most successful pollinizer of ‘Edda’, a self-sterile cultivar, was ‘Opal’. The most successful foreign pollinizer of ‘Opal’ was ‘Mallard’. However, more than two thirds of embryos extracted from ‘Opal’ fruits did not present any alleles not already identified in ‘Opal’, which was expected considering that this plum cultivar was known to be self-fertile. European plums are hexaploid making its allele callings and paternity tests rather complicated. However, the approach used in this study gave clear answers regarding the most successful pollinizers.

Til dokument

Sammendrag

The triploid pear cultivar 'Ingeborg' is currently the main commercial pear cultivar grown in Norway. However, fruit set and subsequent yields of this cultivar have proven to be variable and overall rather low. In order to promote the fruit set, different bioregulators were applied during and after bloom and compared with an untreated control. Investigations were done during the period 2017-2018, at NIBIO Ullensvang, western Norway. Different dosages of both gibberellins (GA3, trade name GIBB 3, 10% active ingredient (a.i.) and GA4/7, trade name Novagib®, 1% a.i.) were applied at full bloom and at petal fall. Additional applications of the growth retardant prohexadione-Ca (trade name Regalis®, 10% a.i.) were applied twice, when bourse shoots had 3-5 leaves and after one month later. Ethephon (Cerone (480 g a.i. L‑1)) was applied three times starting about 7 days after petal fall with ca. 7- to 10-day intervals. All gibberellin applications significantly increased fruit set compared to the untreated control. One single application with GA3 (3 g ha‑1) almost tripled the fruit number per 100 flower clusters when compared with the control (136 and 46, respectively). The yield response was similar (16.8 to 9.6 kg tree‑1, respectively). Similar results occurred with one application of GA4/7 (12 g ha‑1) with the same crop load level, and the fruit weights were similar to the control (130 g). Prohexadione-Ca treatments significantly reduced shoot growth of the pear trees. Two treatments with 125 g ha‑1 or one treatment of 250 g ha‑1 reduced the growth by ~35% but had no significant effect on fruit set and yield. The multiple ethephon applications (275 mL ha‑1 in total) had no effect on both set and shoot growth, and return bloom compared to the untreated or gibberellin treated trees.

Til dokument

Sammendrag

High tunnels offer an intensive and protective production system for many fruit crops. In May 2014, two tractor-accessible Haygrove® multibay tunnel systems were installed on a 10% slope at the experimental farm at Nibio Ullensvang, western Norway (60°19’8.03”N, 6°39’14.31”E). Feathered 1-year old European plum cultivar ‘Opal’ on rootstock ‘St. Julien A’ were planted with two rows per bay at a spacing of 1.5×4 m during 2012. Trees were trained to a central leader as free spindles. In 2016, one tunnel was covered (150 μm clear classic polyethylene film) from before blooming until harvest and one tunnel only covered from mid-July till harvest. Different crop loads levels were established by blossom thinning (each flower 5, 10, and 15 cm apart), and fruitlet thinning (each fruitlet 5, 10, and 15 cm apart) at 10-12 mm fruitlet diameter at the end of June. Treatments were applied on single whole trees in a randomized complete block design with five replications. Climatic parameters were monitored inside and outside the tunnels from mid-June to mid-September. Fruit set, yield data, and fruit quality parameters for each treatment were recorded. Increased thinning distances reduced the fruit set and was highest when thinned at fruitlets. Thinning to 5 cm apart and covered the whole season and 10 cm apart covered one month gave the highest fruit sets of 17.9 and 14.3%, respectively. The yield was positively correlated with the fruit set response, 11.7 kg tree-1 (20 t ha-1) – 5 cm between fruitlets and short-covering versus 3.4 kg – 15 cm distance between flowers and long covering. Both blossom and fruitlet thinned trees when covered got a significant yield reduction compared to covered one month. Thinning at the fruitlet stage resulted in smaller fruits at the same crop level (41.3 g on average) compared to flower thinning for both covering periods (47.2 g). Qualitative traits of ’Opal’ plums (bright yellow ground colour, red over colour, and soluble solid contents) were weakly correlated with the fruit set and was high (16.7% average soluble solids content). The coverage from bloom to harvest time promoted maturity of the plums. From the preliminary results, it can be concluded that fruitlets thinning from uncovered trees and one month covering before harvesting gave the largest crop of premium fruits.

Sammendrag

For plum production to be economically viable, dwarfing rootstocks are essential for establishing high-density orchards, which ensure easier management, lower production costs, and earlier yields. Performance of the semi-dwarfing plum rootstocks ‘Wavit’, ‘Ute’ (both clones of Prunus domestica), and the dwarfing ‘VVA-1’ (Krymsk®1) was compared against the industry standard, ‘St. Julien A’. Onto these rootstocks, scion cultivars ‘Excalibur’, ‘Reeves’, and ‘Valor’ were grafted and assessed in a replicated field trial in western Norway at 60° North. Trees were planted in spring 2006 and the ‘VVA-1’ rootstock in May 2007. Plants were all one-year-old whips, spaced 2.0×4.0 m apart and trained to a central leader as free spindles. Tree vigour, yield, fruit size, fruit quality, and yield efficiency were evaluated for eight subsequent years. Tree size was significantly influenced by the rootstock after eight years of growth. ‘VVA-1’ produced the smallest trees, about half the tree size of ‘St. Julien A’ as measured by trunk cross-sectional area. ‘Wavit’ and ‘Ute’ were similar in size to ‘St. Julien A’. All plum trees came into production slowly. On average the cultivars ‘Excalibur’ and ‘Reeves’ were harvested in mid-September and ‘Valor’ two weeks later. During the period 2011-2014, when trees were fully mature, ‘Reeves’ and ‘Valor’ grafted on the three semi-dwarfing rootstocks resulted in the highest yields tree-1. ‘VVA-1’ resulted in significantly lower yields for ‘Valor’. ‘Excalibur’ was the only cultivar in which ‘VVA-1’ significantly increased yield efficiency. Accumulated yield from 2011-2015 on ‘VVA-1’ was 0.52 kg cm-2 TCSA, 2.3 times more than on ‘St Julien A’. Fruit weight in ‘Excalibur’ and ‘Reeves’ was on average 57 and 62 g, respectively, and not affected by the different rootstocks. ‘Valor’ on ‘VVA-1’ showed a 10 g reduction in fruit weight compared to 59 g fruit weight on the other rootstocks. Fruit soluble solids were on average around 13 °Brix for ‘Excalibur’ and ‘Reeves’ and 16 °Brix for ‘Valor’ and did not differ significantly between trees on the different rootstocks tested. In conclusion, ‘St. Julien A’ was the most reliable semi-vigorous rootstock and resulted in the highest accumulated yields over the first eight years after planting and with favourable effects on fruit quality of all European plum cultivars evaluated. ‘VVA-1’ resulted in trees of low vigour which, especially with ‘Excalibur’, were more precocious and had higher yield efficiencies than all other rootstock scion combinations. If this rootstock is to be used it should be planted at a higher density per area than the semi-dwarfing rootstocks and on fertile soil with fertigation provided.

Sammendrag

Intensive sweet cherry production in tunnel covered orchard systems offer an advantage of reducing rain-induced fruit cracking. In May 2005 four Haygrove multibay tunnel systems were installed on a gentle slope at the experimental farm at Bioforsk Ullensvang, western Norway. In these tunnels, feathered 1-year-old sweet cherry ‘Sweetheart’/Colt trees were planted with two rows at a spacing of 2×4 m in each tunnel. Each tunnel was split into two halves and covered from the end of April to beginning of September with one of two different plastic covers, having different light spectral transmittance; Luminance THB film (absorbing infrared light) and traditional Visqueen clear UV polythene film. Climatic parameters were monitored inside and outside the tunnels from the beginning of May to the beginning of September each year and yield data and fruit quality parameters were recorded. In 2009, from May 7 to September 16 the average temperature measured outside the tunnels was 14.3°C. Temperatures exceed 25°C only on two days. Temperatures inside the tunnels were 0.3°C higher on average during the entire season but exceeded 30°C on the same two hot days. Temperatures under the Luminance film were slightly lower compared to the clear film and especially reduced the temperature build up on sunny days. The harvest period was the second half of August. Average yield tree-1 was 8.8 kg (11 t ha-1) in the fourth leaf and 18.8 kg (23.5 t ha-1) fifth leaf. There were no yield differences between the two different films. Fruit size measurements found that 80% of the fruits were larger than 30 mm in diameter in the fourth leaf and 51% in the fifth leaf. Total soluble solid content was generally high (17-18%) and no significant differences were found between the different films.

Til dokument

Sammendrag

Phenological observations are considered to be sensitive tools for identifying plant responses to climatic changes. Over the last 10 years, the onset of the phenophases of sweet cherry (Prunus avium L.) during spring tended to be earlier than the previous two decades in Ullensvang, western Norway. The effects of air temperature during the winter and spring months were evaluated during two quinquennia (5-year periods), 1996-2000 (Q1) and 2003-2007 (Q2) selected due to similar mean winter and early summer temperatures, but markedly different spring temperatures. Average January-February temperatures were similar (3.3°C) in both of these two 5-year periods. However, average March and April temperatures were slightly warmer (4.0 vs. 3.2°C) and (7.3 vs. 6.9°C), respectively, in Q2 vs. Q1. These increases resulted in significantly earlier flower development. Average temperatures during the first half of May were similar for both quinquennia (10.2 vs. 10.1°C). The start of flowering (first bloom) of early maturing ‘Burlat’ and mid-season ‘Van’ were significantly different. Timing of flowering phenophases were statistically different between Q1 and Q2 for both cultivars. Mean data for ‘Burlat’ and ‘Van’ first bloom were 8 days earlier during Q2, May 2 for ‘Burlat’ and May 1 for ‘Van’. Full bloom occurred 3 days after first bloom and flowering ended 14 days after first bloom. First bloom during Q2 required 221 Baskerville-Emin Growing degree days (GDD) using a base temperature of 2°C. For the same time period in Q1, only 197 GDD were accumulated, which supports the observed temperature differences. Furthermore, we propose a flowering model for full bloom of both ‘Burlat’ and ‘Van’ in Ullensvang, which requires 254 Baskerville-Emin GDD using a base of 2°C starting on March 1.

Sammendrag

Due to a late harvesting season compared to that found in other European countries, the sweet cherry industry in Norway is now expanding, aiming for export markets. Cultivars producing high quality fruit that ripen late (late July and throughout August) and that are suitable to grow in high density production systems are sought. In addition, early ripening cultivars are sought for local marketing in early and middle July. Testing cultivars and advanced selections has been carried out at Ullensvang Research Centre since 1959. During the last decade, 130 cultivars and advanced selections have been included in the testing program. Important parameters like fruit size, fruit firmness, low fruit cracking, high and precocious yield, fresh appearance and good flavour have been evaluated. Based on the results from this testing program, the following cultivars are currently recommended: a) for early season: `Burlat", `Moreau" and `Merchant", b) for mid-season: `Giorgia", `Chelan", `Samba", `Techlovan" and `Van", c) for late season: `Lapins", `Kordia", `Regina" and `Sweetheart".

Sammendrag

Some high density sweet cherry orchards in Norway suffer from decay of trees resulting in death or reduced vigour of trees. A survey monitoring healthy and infected trees from several orchards found differences between cultivars and rootstocks in sensitivity of tree decay. In order to investigate this cherry tree decay further, new field trials were established in 2002 with trees of the cultivar Van grafted on the two rootstocks Prunus avium seedling and Colt and trained as central leader trees. Two parallel trials were planted; one in the soil of an old cherry orchard and the other in the soil from agricultural land where no fruit production had been conducted in advance. During the first years significant larger annual vegetative growth measured as trunk girth, annual shoot growth and leaf areas were registered from the trees growing in the virgin soil. In the replanted cherry soil, trees grafted on the rootstock Colt grew more vigorously than the seedling rootstock based on leaf areas and shoot growth measurements. The rootstock Colt may be the answer for avoiding cherry replant diseases.

Sammendrag

Histological properties of the graft union between a rootstock and scion may provide a mechanistic explanation why dwarfing rootstocks are able to reduce the growth of the tree. In order to investigate the relationship between growth and the amount of functional xylem tissue of potted sweet cherry trees, an experiment was conducted during 2002-2003. One year old field budded and bench grafted (from greenhouse) sweet cherry trees of the cultivars Van, Ulster and Lapins in all combinations of the three rootstocks Prunus avium seedling, Colt and Gisela 5 were grown in pots for two growing seasons. After shoot extension had terminated when trees were in full leaf the second year, the total growth of the different parts of the trees and the functional area using safranin staining were measured. The total mass production (tree dry weight, the length of two year old wood and number of leaves) was significantly larger in the budded trees. Similarly the trunk cross sectional area was significantly larger 10 cm above and in the middle of the graft union, but not 10 cm below it. The Colt trees were the most vigorous followed by the seedling and Gisela 5. Minor differences between the different cultivars were registered. Xylem staining with aqueous safranin combined with quantitative image analysis showed that the rootstock stem had a higher proportion of stained tissue than the scion stem. Sections taken in the middle of the graft tissue and 10 cm above showed that the proportion of stained tissue declined proportionally with the distance from the roots. The total area of stained stem xylem was larger for the two vigorous rootstocks compared to Gisela 5. Small differences were observed between cultivars and propagation methods.

Sammendrag

The performances of the plum rootstocks Plumina® Ferlenain, Ishtara® Ferciana, Jaspi® Fereley and the pentaploid open pollinated seedling of Mariana P 8-13 compared with St. Julien A as a standard, for the cultivars "Opal" and "Reine Claude GF 1119" were assessed in a field trial in western Norway at 60" North. This trial was one part of an international plum rootstock trial located in seven European countries and organized from INRA Bordeaux. Trees were planted in spring 1994; spaced 2.0 x 4.0 m and formed with a central leader as free spindles. Soil management was grass in the alleyways and herbicide strips 1-m wide along the tree rows. Tree vigour, yield, fruit size and yield efficiency were evaluated for the seven subsequent years. Tree size was significantly affected by the rootstocks. P 8-13 produced the largest trees for both cultivars as measured by trunk cross-sectional area. The smallest trees were produced on Plumina® Ferlenain for the cultivar `Opal" and on Jaspi® Fereley for `Reine Claude". The cultivar `Opal" was the most productive and gave three times larger crop than "Reine Claude" on average for the six cropping years. The "Reine Claude" trees came two years later into production than "Opal". There were small differences between the different rootstocks in productivity: However, the rootstock Plumina® Ferlenain produced significant lower crop than the other rootstock for `Opal". Trees on Jaspi® Fereley were the most yield efficient for `Opal" and Plumina® Ferlenain for `Reine Claude". The fruit sizes were in general medium to small for both cultivars and became little affected by the different rootstocks. The average fruit size was about 29 g for `Opal" and 22 g for `Reine Claude". Fruit quality characterized by the content of soluble solids was high for `Reine Claude" with average 20 % and 15 % for `Opal" and did not differ much between trees on the various rootstocks.

Sammendrag

The performances of the plum rootstocks Ferlenain, Ishtara, Jaspi and P 8-13 compared with St. Julien A as a standard, for the cultivars `Opal" and `Reine Claude GF 1119" were assessed in a field trial in western Norway at 60° North. This trial was one part of an international plum rootstock trial located in seven European countries and organized from INRA Bordeaux. Trees were planted in spring 1994; spaced 2.0 x 4.0 m and formed with a central leader as free spindles. Soil management was grass in the alleyways and herbicide strips 1-m wide along the tree rows. Tree vigour, yield, fruit size and yield efficiency were evaluated for the seven subsequent years. Tree size was significantly affected by the rootstocks. P 8-13 produced the largest trees for both cultivars as measured by trunk cross-sectional area. The smallest trees were produced on Ferlenain for the cultivar `Opal" and on Jaspi for `Reine Claude". The cultivar `Opal" was the most productive and gave three times larger crop than "Reine Claude" on average for the six cropping years. The `Reine Claude" trees came two years later into production than `Opal". There were small differences between the different rootstocks in productivity: However, the rootstock Ferlenain produced significant lower crop than the other rootstock for `Opal". Trees on Jaspi were the most yield efficient for `Opal" and Ferlenain for `Reine Claude". The fruit sizes were in general medium to small for both cultivars and became little affected by the different rootstocks. The average fruit size was about 30 g for `Opal" and 25 g for `Reine Claude". Fruit quality characterized by the content of soluble solids was high for `Reine Claude" with average 20 % and 15 % for `Opal" and did not differ much between trees on the various rootstocks.

Sammendrag

Observasjonar om blomstringstid, blomstermengd og fruktsetting vart innsamla frå sortsprøvefelta i søtkirsebær ved Bioforsk Ullensvang forskingssenter i perioden 1993 – 2005. Sortane var poda på grunnstammene Colt, Prunus avium L. frøstamme og Gisela 5. Det var tydelege skilnader i blomstringstid og - mengd mellom dei ulike sortane, mellom tre på ulike grunnstammer og åra. Blomstringstida har starta tidlegare i dei siste åra. Dei mest avlingssikre sort/grunnstamme-kombinasjonane har både høg blomstermengd og fruktsettingsgrad. Ei oppdatert liste over kva sterilitetsgruppe sortane høyrer heime i er presentert.

Sammendrag

I den seine norske plommesesongen saknar ein gode kvalitetssortar. Mildare vêr i siste halvdel av september og fyrst i oktober i seinare år, gjer at sortar som modnar sist i september er meir aktuelle og dyrka enn før. Den kanadiske plommesorten Valor har vorte dyrka i grannelanda våre i dei siste åra og er kjenneteikna med tidleg og stor avling og med mørkeblå, store frukter av høg kvalitet. Innleiande prøvedyrking av denne plommesorten ved Bioforsk Ullensvang stadfester desse eigenskapane.

Sammendrag

Dyrkingseigenskapar av 21 søtkirsebærsortar vart vurderte ved Bioforsk Ullensvang: Fylgjande søtkirsebærsortar har gode eigenskapar: Chelan, Giorgia, Samba, Techlovan og Van med modning i siste veka i juli og Lapins, Kordia, Regina og Sweetheart sist i sesongen. I tillegg er Stardust aktuell sort med ljos raud dekkfarge.

Sammendrag

Due to a late harvesting season compared to that found in other European countries, the sweet cherry industry in Norway is now expanding, aiming for export markets. Cultivars producing high quality fruit that ripen late (late July and throughout August) and that are suitable to grow in high density production systems are sought. In addition, early ripening cultivars are sought for local marketing in early and middle July. Testing cultivars and advanced selections has been carried out at Ullensvang Research Centre since 1959. During the last 6 years, approximately 130 cultivars and advanced selections have been included in the testing program. Important parameters like fruit size, fruit firmness, low fruit cracking, high and precocious yield, fresh appearance and good flavour are evaluated. Based on the results from this testing program, the following cultivars are currently recommended: a) for early season: `Burlat", `Moreau" and `Merchant", b) for mid-season: `Giorgia", `Chelan", `Samba", `Techlovan" and `Van", c) for late season: `Lapins", `Kordia", `Regina" and `Sweetheart".

Sammendrag

Some high density sweet cherry orchards in Norway suffer from decay of trees resulting in death or reduced vigour of trees. A survey has been conducted monitoring healthy and infected trees from several orchards. The nutritional statuses of the soil and in the trees were in general in accordance with general accommodation. Different species of root nematodes were identified with levels above the damage of thresholds. Neither insects, diseases, bacterials nor virus were registered as the main reason for this dieback. However, differences between cultivars and rootstocks sensitivity were observed. In order to investigate this cherry tree decay further, new field trials were established in 2001 with trees of the cultivars Van and Kristin grafted on the two rootstocks Prunus avium seedling and Colt and trained as a central leader trees. Two parallel trials were planted; one in the soil of on old cherry orchard and the other in the soil from agricultural land where no fruit production has been conducted in advance. During the first years significant larger annual vegetative growth measured as trunk cross sectional area and annual shoot growth were registered from the trees growing in the agricultural soil. In the replanted cherry soil, trees grafted on the rootstock Colt grew more vigorously than the seedling rootstock based on leaf areas and shoot growth measurements. The first significant crop is expected in 2005.

Sammendrag

Sweet cherry trees sometimes suffer from dieback symptoms under Scandinavian growing conditions. Some combinations of cultivars and rootstocks are more susceptible to this than others. The graft union between a rootstock and a scion is a junction between two different tissues. Differences in tissue development in the union may provide a mechanistic explanation of inhibiting transport of water and nutritional substances and likely inhibit growth of the scion. In order to investigate the relationship between growth and the amount of functional xylem tissue of potted sweet cherry trees, an experiment was conducted during 2002-2003. One year old field budded and bench grafted (from green house) sweet cherry trees of the cultivars Van, Ulster and Lapins in all combinations of the three rootstocks Prunus avium seedling, Colt and Gisela 5 were grown in pots for two growing seasons. After shoot extension had terminated when trees were in full leaf the second year, the total growth of the different parts of the trees and the quantification of functional area using safranin staining were conducted. The total mass production (tree dry weight, the length of two year old wood and number of leaves) was significant larger in the budded trees. Similarly the trunk cross sectional area was significant larger 10 cm above and in the middle of the graft union, but not 10 cm below. The Colt trees were the most vigorous followed by the seedling and Gisela 5. Small differences between the different cultivars were registered. Xylem staining with aqueous safranin combined with quantitative image analysis showed that the rootstock stem had a higher proportion of stained tissue than the scion stem. Sections taken in the middle of the graft tissue and above showed that the proportion of stained tissue declined proportionally with the distance from the roots. The total area of stained stem xylem was larger for the two vigorous rootstocks compared to Gisela 5. Small differences were observed between cultivars and propagation methods.

Sammendrag

Trees of `Discovery" apples growing on dwarf and semi-dwarf rootstocks were assessed in field trials at two sites (western and eastern Norway) at 60° North. The rootstocks included two selections of M.9 (EMLA, RN.29), two from the Polish (P) series (P.59, P.60), three from the Geneva (G) series (G.30, G.78730-026, G.202) and M.26. Trees were planted in the spring 1997 as two years old feather trees, spaced 1.5 x 4 m, trained as slender spindles and evaluated for five subsequent years. Soil management were grass in the alleyways and herbicide strips 1-m wide along the tree rows. Tree size was significantly affected by the rootstocks after five years growth. P.59, G.78730-026 and M.9 RN.29 produced the smallest and G.30 and G.202 the largest trees as measured by trunk cross-sectional area. P.59 and G.30 had the greatest yields per tree, followed by G.202, P.60 and M.9 EMLA. Trees on P.59 were the most yield efficient followed by the two M.9 clones. The fruit density measured as number of fruits per trunk-cross-sectional area showed similar results. The different rootstocks affected little the fruit weights. Fruit quality characterized by the content of soluble solids was in general high and did not differ between trees on the various rootstocks.

Sammendrag

Pollineringstilhøve hjå viktige plommesortar, både nye og eldre, er presenterte. Avalon og Reeves har dårleg pollen, medan Excalibur og Jubileum har godt pollen. For å sikra god pollinering i Reeves er tilrådd å ha to pollensortar i plantinga - Althanns og Opal eller Victoria.

Sammendrag

Sortstilfanget til nasjonal prøving av søtkirsebærsortar i Noreg er god. Sidan 1959 har det vore drive sortsprøving i søtkirsebær ved Ullensvang forskingssenter, Lofthus. Prøvinga har resultert i lansering av ei rad sortar. Forrige sortslisterevisjon vart gjort i 1998. Viktige sortseigenskapar i utprøvinga av søtkirsebærsortar er: fruktfastleik , årviss og høg avling, fruktstorleik, smak, motstand mot rotesoppar, sprekkemotstand og sjølvfertilitet. Berre mørkfarga sortar står på lista. Sortimentet tek sikte på å dekka den norske frisk-konsummarknaden frå  2.veka i juli til ca. 20. august og eksportmarknaden frå ca. 25. juli og ut sesongen. Fylgjande sortar er aktuelle for dyrking i Noreg (sette opp i modningsrekkefylgje): "Moreau", "Burlat", "Merchant", "Vista", "Giorgia", "Chelan"â, "Samba"â, "Techlovan"â, "Ulster", "Van", "Kristin", "Stella", "Sylvia", "Lapins" og  "Regina".

Sammendrag

Vi prøver i denne artikkelen å gje eit oppdatert oversyn over det vi veit om pollinering i aktuelle eplesortar. Vi drøftar kva omsyn som må takast ved val av pollensort, og har sett opp ein tabell der ein kan gå inn og finne aktuelle kombinasjonar av hovudsort og pollensort. Målgruppe for artikkelen er dyrkarar og rettleiarar.

Sammendrag

Eit dyrkingsproblem er at søtkirsebær-trea utan synlege sjukdomsteikn brått kan stagnera i vekst og døy endå om feltet har fått optimalt stell. For tida er det ingen konkrete rådgjerder for dyrkarane bortsett frå å planta nye tre i staden for dei som gjekk ut. Med finansiering frå Statens Landbruksbank har Planteforsk Ullensvang i samarbeid med Planteforsk Plantevernet gjennomført det eitt-årige prosjektet "Kartlegging av årsaker til tredaude i søtkirsebær" i 1999. Kartleggingsarbeidet var delt i to: 1.Kartlegging av 5 bruk som har problem med tredaude blant medlemene til Hardanger Frukt og Bær med utttak og analyse av nematode-, sopp-, virus- og jord- og bladprøvar saman med feltinspeksjonar. 2. Spørjeundersøking til søtkirsebærdyrkarar ved 5 fruktlager i Ullensvang om tilhøve som kan tenkjast å påverka tredaude i søtkirsebær . Grupper av rotnematodar som gjer skade på frukttrea var registrert i alle hagane og kan såleis vera medverkande til symptoma. Det var også mogeleg å relatera høge populajonar av rotsårnematodar til dårleg tilvekst og høge spiralnematodetal til tidlegare observasjonar av tredaude. Det vart ikkje påvist at ulike insekt, soppar, bakteriar eller virus var primærårsak til denne tredauden. Spørjeundersøkinga viste at mange søtkirsebærdyrkarar meinte det var skilnad mellom kor utsette ulike sortar og grunnstammer var for tredauding i frukthagane. Gjenplanting på same arealet kort tid etter at det var rydda steinfruktplanting fremja tredauding. Lauvtrebarkbillen var årsak til tredaude, men då er diagnosen oftast enkel å stilla.

Sammendrag

Eit dyrkingsproblem er at søtkirsebær-trea utan synlege sjukdomsteikn brått kan stagnera i vekst og døy endå om feltet har fått optimalt stell. For tida er det ingen konkrete rådgjerder for dyrkarane bortsett frå å planta nye tre i staden for dei som gjekk ut. Med finansiering frå Statens Landbruksbank har Planteforsk Ullensvang i samarbeid med Planteforsk Plantevernet gjennomført det eitt-årige prosjektet "Kartlegging av årsaker til tredaude i søtkirsebær" i 1999. Dette var eit oppdrag for Hardanger Frukt og Bær. Kartleggingsarbeidet var delt i to: 1. Kartlegging av 5 bruk som har problem med tredaude blant medlemene til Hardanger Frukt og Bær med utttak og analyse av nematode-, sopp-, virus- og jord- og bladprøvar saman med feltinspeksjonar. 2. Spørjeundersøking til søtkirsebærdyrkarar ved 5 fruktlager i Ullensvang om tilhøve som kan tenkjast å påverka tredaude i søtkirsebær . I desse fem søtkirsebærhagane, var næringstilstanden av makronæringsemne i jorda høg og delvis over det optimale. Ubalanse mellom næringsemna kan vera med og svekka trehelsa til trea. Grupper av rotnematodar som gjer skade på frukttrea var registrert i alle hagane og kan såleis vera medverkande til symptoma. Det var også mogeleg å relatera høge populajonar av rotsårnematodar til dårleg tilvekst og høge spiralnematodetal til tidlegare observasjonar av tredaude. Det vart ikkje påvist at ulike insekt, soppar, bakteriar eller virus var primærårsak til denne tredauden. Grundigare undersøkingar og då særleg av nematodar i jorda bør utførast vidare for å påvisa årsaker til denne tredauden i søtkirsebær og finna mogelege rådgjerder for å bekjempa dei ulike potensielle skadegjerarane.  Spørjeundersøkinga viste at mange søtkirsebærdyrkarar meinte det var skilnad mellom kor utsette ulike sortar og grunnstammer var for tredauding i frukthagane. Gjenplanting på same arealet kort tid etter at det var rydda steinfruktplanting fremja tredauding. Lauvtrebarkbillen var årsak til tredaude, men då er diagnosen oftast enkel å stilla. Kulturmåten som gjødslings- og vatningspraksis verkar mindre inn, men vass-sig på trerøtene var negativt.