Fertility of female ('Hayward', 'Earligreen', 'Tsechelidis' and 'Soreli') and male ('Autari', 'M56', 'Chieftain', 'P1' and 'Belén') kiwifruit in the north of Portugal

J.P.M. Alves, J.R.O. Rodrigues, C.M.M.S. Oliveira
The aim of this study was to study the adaptation of the new Actinidia cultivars (both male and female) in five orchards of the Minho region of Portugal. The female cultivars studied were ‘Tsechelidis’, ‘Soreli’ and ‘Earligreen’, and the male cultivars were ‘Chieftain’, ‘P1’, ‘Autari’, ‘M56’ and ‘Belén’. The fertility index (FI), fertile bud index (FBI) and budbreak index (BI) were calculated. Pollen viability of the male cultivars was also tested. ‘Tsechelidis’ appeared to have increased fertility (BI 56±5%, and FBI 38±8%), but it started to flower almost 1 week earlier than ‘Hayward’, which might pose a problem when selecting the appropriate male cultivar. Male cultivar ‘P1’ seems to match up well with ‘Tshechelidis’, but its pollen germination viability is not the best [median pollen viability 76%; interquartile range (IQR) 71-83%] In the year of the study, the flowering date of ‘Earligreen’ was similar to that of ‘Hayward’, which enables it to be cultivated with the same male cultivars as ‘Hayward’. ‘Earligreen’ showed higher fertility (FI 3.6±0.4) than ‘Hayward’ (FI 3.0±0.5) (P<0.05). ‘Autari’ and ‘M56’ possessed the best pollen germination capacity [median germinated pollen 92.5% (IQR 90-97%, n=18) and 90.7% (IQR 87-93; n=18), respectively]. As for ‘Soreli’, this study observed that it flowered a month earlier than ‘Hayward’, and that it had almost no synchrony of phenology with its male cultivar (‘Belén’). This shows that, in this case, under the soil and climate conditions of the region, a new male cultivar needs to be selected.
Alves, J.P.M., Rodrigues, J.R.O. and Oliveira, C.M.M.S. (2018). Fertility of female ('Hayward', 'Earligreen', 'Tsechelidis' and 'Soreli') and male ('Autari', 'M56', 'Chieftain', 'P1' and 'Belén') kiwifruit in the north of Portugal. Acta Hortic. 1218, 391-396
DOI: 10.17660/ActaHortic.2018.1218.54
Actinidia spp., cultivar adaptation, pollination, pollen viability

Acta Horticulturae