PHENOLOGICAL AND CLIMATIC SIMULATION OF THE LATE FROST DAMAGE IN PLUM ORCHARD UNDER THE CLIMATE CONDITIONS OF ROMANIA

In the continental-temperate climate of Romania, late frosts often affect fruit trees by damaging flowers.
The purpose of this paper is to develop a new simulation model that estimates the phenological dynamics until the end of blossom and estimate the probability of occurrence for climatic accidents caused by late frosts in plum (Prunus domestica) orchards.
The probability of damage was calculated as the simultaneous occurrence of a susceptible phenophase and the critical temperature.
A database of phenological observations was used for bud burst, green tip, early blossom and petal fall in plum (‘Tuleu gras’ cultivar and other 22 cultivars) orchards for a 31 year period (1969–1976, 1985–2007) together with weather data taken from a longer period (1969–2007). In order to apply this study to other regions with no phenological observations, linear and multiple regression equations between various hourly temperatures and the onset of phenophases were computed to simulate the phenological dynamics.
The cultivars were grouped into two classes: an early blossom class with the blossom between the 10^th and 11^th of April, and a late blossom class blooming between 13^th and 15^th of April.
One could notice the higher values of the probabilities of damage occurrence for the early cultivars.
The most critical intervals were the 21 through 25 of March and the 21 through 25 of April.
On average for the 23 locations studied, the probability of damage occurrence by late frosts was 2.7% (within the limits of 1.6-6% in periods 21–25 March and 16–20 April).

VIII International Symposium on Modelling in Fruit Research and Orchard Management

E. Chitu, D. Sumedrea, C. Paltineanu

climatic accidents, ‘Tuleu gras’ cultivar, bud burst, green tip, blossom

https://doi.org/10.17660/ActaHortic.2008.803.17