Growing degree-days for the 'Niagara Rosada' grapevine pruned in different seasons.
Int J Biometeorol
; 56(5): 823-30, 2012 Sep.
Article
em En
| MEDLINE
| ID: mdl-21866380
ABSTRACT
Plant growth and development are proportional to biological time, or the thermal time of the species, which can be defined as the integral of the temperature over time between the lower and upper temperature developmental thresholds. The objective of this study was to investigate the efficiency of the growing degree-day (GDD) approach for vines of the 'Niagara Rosada' cultivar pruned in winter and summer seasons, and physiological phases (mobilisation and reserve accumulation) in a humid subtropical region. The experiment was carried out on 13-year-old plants in Piracicaba, São Paulo State-Brazil, evaluating 24 production cycles, 12 from the winter pruning, and 12 from the summer pruning. The statistical design was comprised of randomised blocks, using the pruning dates as treatment 20 July, 4 August, 19 August, and 3 September (winter); 1 February, 15 February, 2 March, and 16 March (summer). Comparison of the mean values of GDD among pruning dates was evaluated by the Tukey test, and comparison between pruning seasons was made by the F test for orthogonal contrasts, both at the 5% probability level. The results showed good agreement between the values of GDD required to complete the cycle from the winter pruning until harvest when compared with other studies performed with the same cultivar grown in the Southern and Southeastern regions of Brazil. However, there was a consistent statistical difference between GDD computed for winter and summer pruning, which allowed us to conclude that this bio-meteorological index is not sufficient to distinguish vines pruned in different seasons and physiological phases applied in humid subtropical climates.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estações do Ano
/
Vitis
/
Agricultura
Tipo de estudo:
Clinical_trials
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Int J Biometeorol
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Brasil