Frost resistance and placement of apricot cultivars in Crimea

   The article presents the results of long-term work on artificial freezing of flower buds of 15 zoned apricot cultivars bred by the Nikitsky Botanical Gardens (NBG) for the period from 1997 to 2025. The studies were conducted in the Greenland (from 1997 to 2009) and TTS 256 Memmert with PO (from 2015 to 2021) climatic chambers. Freezing was carried out at different temperatures, the choice of which depended on the stage of morphogenesis of the generative buds and the calendar timing of the experiment. The zoned Burevestnik cultivar bred by the Nikitsky Botanical Gardens, characterized by increased frost resistance, was used as a control.

   The aim of this study was to summarize the results of artificial freezing of generative buds of 15 zoned apricot cultivars bred by the NBG and to develop recommendations for their placement in the agroclimatic regions of Crimea.

   Cultivars with very high, high, above-average, and average frost resistance were identified. No genotypes with high frost resistance were identified among cultivars with early and early-mid-season ripening fruit. Three genotypes were selected from apricot cultivars with mid- and late-season ripening fruit: one cultivar with very high frost resistance, and two with high frost resistance. Twelve genotypes with average and above-average frost resistance were identified. Determining the frost resistance of flower buds allowed us to substantiate the placement of cultivars in the agroclimatic regions of Crimea. Twelve apricot cultivars with average and above-average frost resistance are recommended for planting in favorable agroclimatic regions. Three cultivars with very high and high frost resistance of flower buds are recommended for unfavorable regions. These varieties can also be grown in favorable agroclimatic regions of Crimea.

1. Opanasenko N.E. Agroclimatic zoning of the Crimea for the cultivation of stone fruit, pome and nut crops. Towards the creation of industrial gardens of fruit crops in the Crimea. Simferopol: PH "Arial", 2017. P. 58-88

2. Program and methodology for the variety study of fruit, small fruit and nut-bearing crops : edited by. ed. E.N. Sedov and T.P. Ogoltsova. Orel: VNIISPK, 1999. 608 p.

3. Smykov A.V., Mesyats N.V. Frost resistance and placement of peach cultivars in the Crimea. Plant Biology and Horticulture: theory, innovation. 2024. 1(170):67-80. doi: 10.25684/2712-7788-2024-1-170-67-80

4. Sholokhov A.M. Study of the morphogenesis of flower buds in connection with variety testing and selection of stone fruits for winter hardiness. Yalta, 1972. 14 p.

5. Atagul O., Calle A., Demirel G., Lawton J.M., Bridges W.C., Gasic K. Estimating Heat Requirement for Flowering in Peach Germplasm // Agronomy. 2022. Vol. 12. P. 1002. doi: 10.3390/agronomy12051002.

6. Doğan Aliseydi, Karaat Fırat Ege, Levent Okan, Asma Bayram Murat. Characterization of new late-spring-frost-tolerant apricot hybrids: physical and biochemical fruit quality attributes volatile aroma compounds // Food Technology. 2023. Vol. 53. № 8. Р. e20220144 doi: 10.1590/0103-8478cr20220144.

7. Demirtas M.N., Atay S., Gokalp K., Yilmaz K.U., Paydaş Kargi S., Ercisli S., Sahin M., Olmez H.A. and Altindag M. Improvement of late blooming drying apricot varieties by crossbreeding // Acta Horticulturae. 2010. № 862: Р. 219-224 DOI: 10.17660/ActaHortic.2010.862.34.

8. Fernandez E., Mojahid H., Fadón E. et al. Climate change impacts on winter chill in Mediterranean temperate fruit orchards // Reg Environ Change. 2023. Vol. 23. № 7. doi: 10.1007/s10113-022-02006-x

9. Golubev A.M., Alyoshina N.A., Anfalov V.E., Kulikov A.A., Vdovenko V.S. Some mechanisms of winter resistance in apricot flower buds in the period of ecodormancy // Agronomy Research. 2021. Vol. 19. № 3. Р. 1487-1503. DOI: 10.15159/AR.21.132.

10. Gorina V.M., Korzin V.V. Long-term Investigations Results of Low Temperatures Influence on Apricot Generative Buds // Acta Horticulturae. 2016. Vol. 1139. P. 363-368. DOI: 10.17660/ActaHortic.2016.1139.63

11. Gorina V., Korzin V., Mesyats N. Apricot breeding for late flowering in Nikita Botanical Gardens // Acta Horticulturae. 2020. Vol. 1282. P. 25-30. DOI: 10.17660/ActaHortic.2020.1282.5

12. Korsakova S., Korzin V., Plugatar Y., Kazak A., Gorina V., Korzina N., Khokhlov S., Makoveichuk K. Modelling of Climate Change’s Impact on Prunus armeniaca L.’s Flowering Time // Inventions. 2023. Vol. 8. №3. Р. 65. doi: 10.3390/inventions8030065.

13. Liu W., Liu N., Zhang Y., Yu X., Sun M., Xu M., Zhang Q., Liu S. Apricot cultivar evolution and breeding program in China // Acta Horticulturae. 2012. № 966. Р. 223-228. DOI: 10.17660/ActaHortic.2012.966.35.

14. Szabó Z., Soltész M., Bubán T., Nyéki J. Low winter temperature injury to apricot flower buds in Hungary // Acta Horticulturae. 1995. Vol. 384. P. 273-276. DOI: 10.17660/ActaHortic.1995.384.41.

15. Szalay L., Papp J., Szabo Z. Evaluation of frost tolerance of peach cultivars in artificial freezing tests // Acta Horticulturae. 2000. Vol. 538. P. 407-410. DOI: 10.17660/ActaHortic.2000.538.71.

16. Szalay L. Frost tolerance and winter hardiness of apricot and peach cultivars (PhD thesis). Budapest, 2001.

17. Szymajda M., Pruski K., Zurawicz Ed., Sitarek M. Freezing injuries to flower buds and their influence on yield of apricot (Prunus armeniaca L.) and peach (Prunus persica L.) // Canadian Journal of Plant Science. 2013. Vol. 93. P. 191-198. DOI: 10.4141/cjps2012-238.

18. Viti R., Andreini L., Ruiz D., Egea J., Bartolini S., Iacona C. & Campoy J.A. Effect of climatic conditions on the overcoming of dormancy in apricot flower buds in two Mediterranean areas: Murcia (Spain) and Tuscany (Italy) // Scientia Horticulturae. 2010. Vol. 124. P. 217-224. DOI: 10.1016/j.scienta.2010.01.001.