Botanical and genetic traits
The variety belongs to the species Actinidia chinensis var chinensis and it is tetraploide (2n = 4x = 116).
Time of budburst
‘Soreli’ budburst anticipates a few days or is contemporary to ‘Hayward’, depending on the location and the season. Bud burst occurs in Udine (46’ 06° lat N, 113 m asl) around March 30th.
Bud fertility is high, like in most A. chinensis selections. The high bud fertility guarantees, under the same bud load per hectare, 30-50 % more yield in comparison to the traditional green kiwifruit varieties. Flowers are single, at least for the limited period during which observations were carried out (2005-2010).
‘Soreli’ flowers 9 days in advance in comparison to ‘Hayward’. Even in this case there is a great variability according to the year and the location. Flowering occurs in Udine around May 17th.
Suggested pollenizer: Belén. Other pollenizers are under scrutiny. It is possible to use pollen of Actinidia deliciosa as well. In such a case, the pollen must have to be stored the year before, provided that the A. deliciosa selections flowers when ‘Soreli’ flowering is over. It is possible to import pollen from Countries of the Southern hemisphere, like New Zealand. This commercial pollen, that can be easily found in the European market, has been successfully used in the pollination of ‘Soreli’.
The fruit of ‘Soreli’ is ovoid-long and regular in shape, the skin colour is brilliant brown, flesh colour is intense yellow, mean fruit weight is approx. 100 g.
Harvesting and storage
Fruit of ‘Soreli’ are harvested with a soluble solid content above 7 ° Brix approx. 30 days before ‘Hayward’. Fruit can be harvested within a period of 20 days with a soluble solid content between 7 and 10 ° Brix.
Fruit storage at normal atmosphere (NA) is limited to 90-120 days. Controlled atmosphere (CA) with the ethylene removal can prolong the storage life up to 6 months.
The consumer’s evaluation is generally good. Acceptance scoring values are similar to ‘Hayward’ and slightly lower than ‘Jintao’. ‘Soreli’ has a good sweetness/acidity balance.
Resistance to diseases
At the time ‘Soreli’ has been evaluated there was no concern about kiwifruit diseases, that were easily controlled by growers through the common good practices and the curing of fruit after the harvest.
For this reason no test has been carried out on resistance/tolerance of ‘Soreli’ to diseases recently reported as sustained by pathogens particularly aggressive towards the kiwifruit crop, such as the kiwifruit wilt caused by Verticillium albo-atrum reported in 2008 in Chile on young Hort 16A kiwifruit plantations (Fullerton et al. New Zealand Plant Protection 61: 393 (2008), Auger e Perez. Plant disease 93 (5): 553 (2009)) and the bacterial canker caused by Pseudomonas syringae pv actinidiae recorded in Italy in 2009 (Balestra et al. Australasian Plant Disease Notes 4: 34-36 (2009)), recorded to be present in China, Japan, South Korea and likely in California and Iran as well (Rees-George et al. Plant Pathology 59: 453-464 (2010)).
At the time this bulletin has been prepared there is no report of damages to ‘Soreli’ orchards due to the pathogens described above, given also the limited diffusion of this cultivar. Reports from licensees and stakeholders are welcome.
Frost and cold resistance
A frost occurred in Springtime 2003 during the ‘Soreli’ selection (-1.9 °C on April 7th and -3.3 °C the day after) allowed to record a good resistance of ‘Soreli’ to early frost in comparison with other selections of the same age and grown in the same block. The fact is partly due to the time of bud burst of ‘Soreli’ which is delayed in comparison with other selections.
As far as winter cold resistance, young plants of ‘Soreli’, 4 years old and overgrafted onto ‘Hayward’, were exposed on December 19-20, 2009 to temperatures at -13 -14 °C. They did not show any apparent reduction on bud fertility diversely from ‘hayward’ that showed a dramatic increase of the percentage of the buds that did not swell.
Yet, we observed in several blocks were micropropagated plants of ‘Soreli’ were compared with plants of the same cultivar grafted onto different rootstocks (‘Hayward’ and ‘D1’) that temperatures below -14 °C led to the almost complete lost of scions and the rootstocks had to be reworked. Micropropagated plants equally lost the stem, but they regrew promptly from the roots at Springtime.