Introduction. For some species such as P. armeniaca, overcoming dormancy may be problematic when cold requirements are not satisfied. Moreover, the different positions of flower buds on the tree canopy and on the apical and basal portions of twigs can influence their development. Sampling problems have not been extensively studied. Therefore, the effect of different sectors (west and east), of different heights (top and bottom) of the canopy and of twig portions (medium-apical and medium-basal) on the break of dormancy in the apricot tree was evaluated. Attention was also focused on floral anomalies in relation to the flower bud position on the twig, in order to identify the least variable portion of twigs and thus provide useful information for optimization of periodic bud sampling. Materials and methods. Two cultivars of P. armeniaca with different chilling requirements were chosen: 'San Castrese' and 'Orange Red'. The end of endodormancy was evaluated from December to blooming time by traditional biological approaches, such as increase in flower bud fresh weight and evolution of the bud phenological stage, before and after 7 d under forcing conditions. In addition, the percentage of floral anomalies was considered in relation to the flower bud position on the twig. Results and conclusion. The results showed that canopy and twig positions exerted different effects on the breaking of the flower bud endo-dormancy, and some practical applications can be drawn from them for the best sampling design inside the tree structure: the west orientation of the canopy and the medium-apical portion of the twig were the best positions to obtain an earlier active growth of buds, allowing the prediction of endo-dormancy breaking. The analysis of flower anomalies showed considerable differences depending on the position of the bud on the twig. High percentages of anomalous buds were observed in the medium-basal portion of the twig, which could distort the results on the evaluation of overcoming dormancy, due to a weaker growth trend of flower budsIntroduction. For some species such as P. armeniaca, overcoming dormancy may be problematic when cold requirements are not satisfied. Moreover, the different positions of flower buds on the tree canopy and on the apical and basal portions of twigs can influence their development. Sampling problems have not been extensively studied. Therefore, the effect of different sectors (west and east), of different heights (top and bottom) of the canopy and of twig portions (medium-apical and medium-basal) on the break of dormancy in the apricot tree was evaluated. Attention was also focused on floral anomalies in relation to the flower bud position on the twig, in order to identify the least variable portion of twigs and thus provide useful information for optimization of periodic bud sampling. Materials and methods. Two cultivars of P. armeniaca with different chilling requirements were chosen: 'San Castrese' and 'Orange Red'. The end of endodormancy was evaluated from December to blooming time by traditional biological approaches, such as increase in flower bud fresh weight and evolution of the bud phenological stage, before and after 7 d under forcing conditions. In addition, the percentage of floral anomalies was considered in relation to the flower bud position on the twig. Results and conclusion. The results showed that canopy and twig positions exerted different effects on the breaking of the flower bud endo-dormancy, and some practical applications can be drawn from them for the best sampling design inside the tree structure: the west orientation of the canopy and the medium-apical portion of the twig were the best positions to obtain an earlier active growth of buds, allowing the prediction of endo-dormancy breaking. The analysis of flower anomalies showed considerable differences depending on the position of the bud on the twig. High percentages of anomalous buds were observed in the medium-basal portion of the twig, which could distort the results on the evaluation of overcoming dormancy, due to a weaker growth trend of flower buds

The influence of sampling from different canopy positions on the evaluation of flower bud anomalies and dormancy in apricot (Prunus armeniaca L.)

VITI, RAFFAELLA;GUERRIERO, ROLANDO
2003

Abstract

Introduction. For some species such as P. armeniaca, overcoming dormancy may be problematic when cold requirements are not satisfied. Moreover, the different positions of flower buds on the tree canopy and on the apical and basal portions of twigs can influence their development. Sampling problems have not been extensively studied. Therefore, the effect of different sectors (west and east), of different heights (top and bottom) of the canopy and of twig portions (medium-apical and medium-basal) on the break of dormancy in the apricot tree was evaluated. Attention was also focused on floral anomalies in relation to the flower bud position on the twig, in order to identify the least variable portion of twigs and thus provide useful information for optimization of periodic bud sampling. Materials and methods. Two cultivars of P. armeniaca with different chilling requirements were chosen: 'San Castrese' and 'Orange Red'. The end of endodormancy was evaluated from December to blooming time by traditional biological approaches, such as increase in flower bud fresh weight and evolution of the bud phenological stage, before and after 7 d under forcing conditions. In addition, the percentage of floral anomalies was considered in relation to the flower bud position on the twig. Results and conclusion. The results showed that canopy and twig positions exerted different effects on the breaking of the flower bud endo-dormancy, and some practical applications can be drawn from them for the best sampling design inside the tree structure: the west orientation of the canopy and the medium-apical portion of the twig were the best positions to obtain an earlier active growth of buds, allowing the prediction of endo-dormancy breaking. The analysis of flower anomalies showed considerable differences depending on the position of the bud on the twig. High percentages of anomalous buds were observed in the medium-basal portion of the twig, which could distort the results on the evaluation of overcoming dormancy, due to a weaker growth trend of flower budsIntroduction. For some species such as P. armeniaca, overcoming dormancy may be problematic when cold requirements are not satisfied. Moreover, the different positions of flower buds on the tree canopy and on the apical and basal portions of twigs can influence their development. Sampling problems have not been extensively studied. Therefore, the effect of different sectors (west and east), of different heights (top and bottom) of the canopy and of twig portions (medium-apical and medium-basal) on the break of dormancy in the apricot tree was evaluated. Attention was also focused on floral anomalies in relation to the flower bud position on the twig, in order to identify the least variable portion of twigs and thus provide useful information for optimization of periodic bud sampling. Materials and methods. Two cultivars of P. armeniaca with different chilling requirements were chosen: 'San Castrese' and 'Orange Red'. The end of endodormancy was evaluated from December to blooming time by traditional biological approaches, such as increase in flower bud fresh weight and evolution of the bud phenological stage, before and after 7 d under forcing conditions. In addition, the percentage of floral anomalies was considered in relation to the flower bud position on the twig. Results and conclusion. The results showed that canopy and twig positions exerted different effects on the breaking of the flower bud endo-dormancy, and some practical applications can be drawn from them for the best sampling design inside the tree structure: the west orientation of the canopy and the medium-apical portion of the twig were the best positions to obtain an earlier active growth of buds, allowing the prediction of endo-dormancy breaking. The analysis of flower anomalies showed considerable differences depending on the position of the bud on the twig. High percentages of anomalous buds were observed in the medium-basal portion of the twig, which could distort the results on the evaluation of overcoming dormancy, due to a weaker growth trend of flower buds
Viti, Raffaella; Bartolini, S; Guerriero, Rolando
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11568/203829
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