Darius Kviklys
Research Scientist
(+47) 413 24 561
darius.kviklys@nibio.no
Place
Ullensvang
Visiting address
NIBIO Ullensvang, NO-5781 Lofthus
Abstract
The successful introduction of new cultivars depends on the evaluation of complex parameters essential for the consumers, market, and fruit producers. A new scab-resistant apple cultivar, ‘Wuranda’ (SQ159/Natyra®/Magic Star® × Honeycrisp), recently introduced in Norway and managed under the name Fryd©, is prone to biennial bearing. Therefore, one of the first tasks, investigated in Southwestern Norway by the Norwegian Institute of Bioeconomy Research, NIBIO-Ullensvang in 2021–2024, was the establishment of optimal crop load level based on the combination of productivity, fruit quality, and return bloom. The apple cultivar Fryd (‘Wuranda’) was propagated on ‘M.9’ rootstock and planted in 2019. The trial was performed in the same orchard for four consecutive years, starting three years after planting. Crop load level affected average fruit mass but had no impact on cv. Fryd fruit quality parameters at harvest such as blush, ground color, firmness, soluble solid content, or starch degradation. Fruit size variation was diminished by crop load regulation, and most fruits fell into 2–3 grading classes. Crop load, not the yield per tree, was the determining factor for the return bloom. The optimal crop load level depended on the orchard age. To guarantee a regular bearing mode of cv. Fryd planted on M.9 rootstock at a 3.5 × 1 m distance and trained as slender spindle, crop load of 5.5–6 fruits cm−2 TCSA (trunk cross-sectional area) in the 3rd year, 7.5–8 fruits cm−2 TCSA in the 4th year, and 6.5–7 fruits cm−2 TCSA in the 5th year should be maintained.
Authors
Darius KviklysAbstract
European fruit research institute network (EUFRIN) has started coordinated apple rootstock trials across the Europe in 2017. Until now, nineteen research institutions from 14 countries established 6 apple rootstock trials where 33 apple rootstocks of different vigour are in tests. Introduction of new apple orchard designs, multileader canopies usually require more vigorous rootstocks. Investigations of semi-dwarfing apple rootstocks ‘PFR1’ and ‘PFR3’ (New Zealand), ‘G.935’ and ‘G.202’ (US), ‘EM_01’ (UK) and ‘G.11’ as control were performed with apple ‘Galaval’ in Spain, France, and Lithuania during 2017-2023. On the average of five trial sites, the most vigorous trees were on ‘EM_01’, ‘PFR1’ and ‘PFR3’, exceeding vigour of trees on ‘G.11’ by 61 – 84%. Apple trees on rootstocks ‘PFR1’, ‘PFR3’ and ‘G.935’ produced higher cumulative yields, ‘G.202’ similar and ‘EM_01’ significantly lower yield comparing with ‘G.11’. Fertility index of ‘G.935’ equalled fertility of dwarfing ‘G.11’. Fertility index of ‘PFR3’ was similar to ‘G.202’, and the lowest was recorded for ‘EM_01’. Average fruit size did not depend on rootstocks. Rootstock – site interaction was not significant for tree vigour, fruit size, however significant interactions were recorded for cumulative yield and fertility index.
Authors
Darius KviklysAbstract
European fruit research institute network (EUFRIN) has started coordinated apple and pear rootstock trials across the Europe in 2017. First pear rootstock trial was established in 2019 where quince rootstocks from NIAB (UK) breeding program ‘QR196-9’ and ‘QR530-11’ were compared with rootstocks ‘Adams’ and ‘Sydo’. Investigations were conducted with pear cultivar ‘Conference’ in Spain, Romania, Poland and Norway during 2019-2023. In all sites the most vigorous pear trees grew on ‘QR196-9’ rootstock. On the average of four trial sites, the weakest growth was recorded on ‘QR530-11’, except the Spanish site. Pear trees on rootstock ‘Adams’ produced the highest cumulative yields. Cumulative yields on other rootstocks were significantly lower by 16-23% without significant differences between them. However, site geographical position, climate and soil properties had a significant effect on rootstock performance. Similar to trees on ‘Adams’ high pear yield in Spain was harvested from trees on ‘QR196-9’; on ‘QR530-11’ rootstock in Poland, but ‘Sydo’ and ‘QR530-11’ rootstocks gave the highest yield in Romania. On the average of all sites, the least cumulative fertility index was recorded on ‘QR196-9’. Significant rootstock site interactions were revealed: rootstock ‘Adams’ had the highest cumulative fertility index in Spain and Norway, while rootstock ‘QR530-11’ in Poland and Romania.