FROST TOLERANCE STUDIES IN APRICOT VARIETIES

In Hungary frost damages on apricot were evaluated according to varieties.
Ceglédi hajnalpir /Scarlet Aurora of Cegléd/, Magyar kajszi /Hungarian Best/, Ligeti óriás /Giant of Liget/, Szegedi mammut /Mammut of Szeged/, Ceglédi óriás /Giant of Cegléd/ proved to be the tenderest.
Mandula kajszi /Almond Apricot/ and Rakovszky were hardy, Kécskei rózsa /Apricot of Kécske/ C.320 and Borsi rózsa /Rose of Borsi/ have been found very hardy.

Cold injury to flower organs was assessed in different phenophases.
Many varieties have moderate bud mortality after artificial freezing from – 22 to – 25°C in December, but in January high bud mortality was recorded at – 25°C, this value was equal to – 15°C in February.
Average injury to flower organs was high in red budding stage at – 10°C, and in white budding stage at – 5°C. Blooms survived at – 1.6°C, while fruits after setting could be damaged at – 0.6°C. Artificial freezing for 24 hours once causes less injury than freezing for 4 hours 2 times.
Determining the number of dead flower buds by dissection of those was less reliable then forcing.

VIII International Symposium on Apricot Culture and Decline

F. Nyujtó, Z. Erdös

https://doi.org/10.17660/ActaHortic.1986.192.56