Drought and adverse spring frost response of four plum scion/rootstock combinations in the conditions of South Central region of Bulgaria

Plum (Prunus domestica L.) is one of Bulgaria’s main stone fruit species grown all around the country.
Laboratory and field tests of the new plum clonal rootstock ‘Docera 6’ (P. domestica × P. cerasifera), conducted at the Fruit Growing Institute – Plovdiv, define it as a promising rootstock in terms of its reaction to the Plum pox virus (PPV). The characteristics that the rootstock induces to the grafted cultivar are essential to the plum growers.
This study aimed to evaluate the abiotic stress response of the cultivars ‘Topgigant Plus’ and ‘Jojo’ grafted on ‘Docera 6’ and Prunus cerasifera Ehrh.
The latter is the most commonly used rootstock for plum in Bulgaria.
The research was conducted in an experimental orchard at the Fruit Growing Institute in 2021, where freezing air temperatures in the spring and a continuous drought period in the summer affected the trees.
In these abiotic stress conditions, the dates of phenological growth stage “flowering”, percentage of frost injured flowers, water deficiency in the leaves, and fruit biometry were determined.
The data showed that the percentage of frost injuries varied with cultivar but not rootstock.
In continuous drought conditions, the water deficiency calculated for the cultivars grafted on the clonal rootstock was higher compared to the trees grafted on the seedling Prunus cerasifera Ehrh – 33.24% for ‘Jojo’/‘Docera 6’ 27.17% for ‘Jojo’/P. cerasifera and 22.49% for ‘Topgigant Plus’/‘Docera 6’, 19.16% for ‘Topgigant Plus’/P. cerasifera.

XXXI International Horticultural Congress (IHC2022): International Symposium on Adaptation of Horticultural Plants to Abiotic Stresses

N. Dimitrova, M. Nesheva, N. Neshev

abiotic stress, Prunus domestica L., rootstock, ‘Docera 6’, ‘Jojo’, ‘Topgigant Plus’

https://doi.org/10.17660/ActaHortic.2023.1372.9