PHENOLOGICAL AND CLIMATIC MODELLING OF THE LATE FROST DAMAGE IN APRICOT ORCHARDS UNDER THE CHANGING CLIMATIC CONDITIONS OF SOUTH-EASTERN ROMANIA
The purpose of this paper is to apply a new simulation model that estimates the phenological dynamics until the end of blossoming and the occurrence probability of late frost climatic accidents in apricot (Prunus armeniaca L.) orchards. The probability of damage was calculated as the simultaneous occurrence of a susceptible phenophase and the critical frost temperature. A database of phenological observa-tions was used for calyx red, early blossom and petal fall in apricot (Umberto, C.R. 2-63, Sirena, Neptun and Selena) orchards over a 24-year period (1985-2008), together with weather data taken over the same period. No statistical differences were recorded between the phenophase onset dates of the five cultivars under surveillance. While the average and maximum temperatures for the February to April interval have increased over the studied 24 years (the average by 0.99°C and the maximum by 1.30°C in 10 years), the minimum has remained almost stationary (only 0.75°C in 10 years, but trend is not statistically assured), the calyx red, the onset and the end of the blooming phenophase have gradually started earlier. Therefore, if 25 years ago the calyx red onset and the of blossoming onset were recorded closed to 7th and the 12th of April respectively (for the five studied cultivars), now those phenomena are taking place on 23rd and the 28th of March respectively (15 days earlier). Under these circumstances, the probability of damage occurrence by late frosts of all three pheno¬phases, has increased from 1.5% in the intervals 10-20 of March in the 1981-1992 period up to 11.4% between 1-5 of April in the 2001-2008 period.
Chitu, E., Sumedrea , D., Chitu, V., Topor, E., Paltineanu , C., Dumitru, M.L., Ionita , A.D. and Filipescu, L. (2011). PHENOLOGICAL AND CLIMATIC MODELLING OF THE LATE FROST DAMAGE IN APRICOT ORCHARDS UNDER THE CHANGING CLIMATIC CONDITIONS OF SOUTH-EASTERN ROMANIA. Acta Hortic. 919, 57-64
climatic accidents, 'Umberto' cultivar, calyx red, first bloom, in the shuck