|Authors: ||P.C. de S. Leao, D.A.R. Gonҫalves, J.P.D. Costa|
|Keywords: ||Vitis vinifera L., grapevine, phenology, thermal requirements|
The biometeorological index has been widely used for the prediction of phenological stages in the planning of crop practices in tropical vines.
The purpose of this study was to characterise and compare the duration (in days) and thermal requirements (in degree-days NDASH DG) of five stages of the phenological cycle of the twelve most important table grape cultivars in Brazil, divided into two groups: seeded and seedless table grapes.
The study was carried out on grapevines from the Germplasm Bank, Juazeiro, Bahia, Brazil, through four growing seasons (2010-2011). Grapevines grafted on the rootstock IAC 572 'Jales' were drip irrigated and pruned twice a year.
The accumulation of days and thermal requirements were determined for the same plants on four consecutive pruning dates.
Two base temperatures (10°C and 12°C) were used.
The number of days and heat requirements in degree-days were evaluated for the following phenological phases according to the Eichhorn and Lorenz modified scale: pruning or bud swelling to beginning of shooting (Bsw-Bsh); beginning of shooting to full bloom (Bsh-Bl); full bloom to fruit setting (Bl-FS); fruit setting to beginning of maturation (FS-BMt); and beginning of maturation to harvest (BMt-HA). 'BRS Clara' and 'Niagara Rosada' were the earliest cultivars in each group, requiring 101 and 116 days to complete the phenological cycle, respectively, while the latest cultivars were 'Patricia' and 'Crimson Seedless', taking 128 days from pruning to harvest in both cultivars.
The thermal requirements ranged from 1,197.2 DG in 'BRS Morena' to 1,521.5 DG in 'Patricia', and the base temperature of 10°C proved to be the most suitable for this purpose.
Download Adobe Acrobat Reader (free software to read PDF files)
URL www.actahort.org Hosted by KU Leuven