Peach_LT50_Temp

The samples were collected from the experimental orchards of the Faculty of Horticultural Science of Szent István University. Our collection was in Szigetcsép (47°15'10.6"N 18°57'26.6"E) until 2007. Three years before the excision of this plantation, we set up a new experimental plantation in Soroksár (47°23'51.8"N 19°09'03.2"E), where we continued our studies. The environmental conditions of the two production sites are very similar. The examination of the phenological process and frost hardiness of peach cultivars was carried out parallel in both plantations in 2004, 2005 and 2006. No significant difference was found between the two production sites in these processes. Data are from Szigetcsép from September 1994 to April 2006, and from Soroksár from September 2006 to April 2019. The training system of both plantations is slender spindle with 4 x 2.5 metres spacing with almond seedling rootstocks. In the orchard, integrated plant protection was applied. One-year-old shoots from six trees of each of the peach cultivars ‘Venus’, ‘Redhaven’ and ‘Piroska’ were collected for this study. Artificial frost treatment was carried out in climatic chambers Conviron C-912 and Rumed 3301 (Rubarth Apparate GmbH, Laatzen, Germany). The flower buds were tested 1-2 times a month from the 1st of September until the trees blossomed. Starting from the autumn of 1994, 25 dormancy periods were available to observe up to the spring of 2019. Since in three years (1996/97, 2001/02, 2011/2012) severe natural frost damage occurred, in these years there was no appropriate amount of flower buds for accurate observations. Three or four appropriate freezing temperatures were used at each testing date, according to the rate of dormancy. Both cooling and warming were performed at a rate of 2°C/h and shoots were kept at the given freezing temperature for four hours. Five one-year-old long shoots were used for all of treatments. After freezing, all the shoots were kept at room temperature until analysis. The flower buds were cut longitudinally and the frost damage was determined based on the rate of discolouration of tissues (green – unharmed, brown – frost damaged) on a numerical scale from 0 % to 100 %, respectively. The mean value of frost hardiness (LT50) was calculated using a linear regression model, assuming that the section of the hardiness sigmoid curve between 20% and 80% can be regarded as linear (Gu, 1999). Peach_LT50_Temp_Mendeley.xlsx Date (YYY.MM.DD); daily max temperature; daily min temperature; LT50 values for peach varieties ‘Venus’, ‘Redhaven’, ‘Piroska’, respectively. Data are from Szigetcsép from September 1994 to April 2006, and from Soroksár from September 2006 to April 2019.