ISHS Acta Horticulturae 701: XII International Symposium on Apricot Culture and Decline
THERMAL REQUIREMENT FROM BLOOMING TO RIPENING IN SOME APRICOT CULTIVARS |
| Authors: | R. Guerriero, P. Monteleone |
| Keywords: | Prunus armeniaca, fruit growth, thermal sum, degree days, G.D.H. |
| Abstract:
Distribution of the character 'length of the interval between blooming and ripening' (B.-R.I.L.) was studied in a collection of apricot cultivars in coastal Tuscany, using phenoclimatic data gathered over more than ten years. For a shorter, but more homogeneous length of time (8 years), 16 among the most representative cultivar were studied to calculate the thermal sum of the corresponding periods between blooming and ripening, using minimum and maximum daily temperatures. Different methods for calculating thermal sums were compared: 1) Degree Days (DD), 2) Huglin Bioclimatic Index (H.B.I) and 3) Growing Degree Hours (G.D.H.), adopting three different thermal thresholds: 5° C, 8° C, 10° C., for the first two methods. Mean values are provided with standard deviation and coefficient of variability. Comparative investigation of different years for the same cultivar showed that the lowest thermal threshold (5° C) induced least variability. The most suitable method appeared to be G.D.H.The B.-R.I.L. for each cultivar was characterised by a well defined thermal sum which remained fairly constant over the years when climatic trends were normal. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
