Analyse de l'étalement temporel de la floraison et influence sur la variabilité intra-arbre de la chute et de la croissance précoce des pêches

Abstract

This study attempted to explain peach abscission and early growth variabilities. We assumed that flower anthesis variability was indicative of early competition for carbohydrates, presumedly determinant for fruit set and early growth. From this viewpoint, the fruits resulting from early flowers should be advantaged. In a first step, we described and analysed the pattern of flowering dates within peach trees. In a second step, we studied the relationship between this pattern and the variability of fruit abscission and growth. At the tree level, the flowers started opening from the base towards the top, but at the shoot level the flowers opened from the apex down to the base. Single flowers opened 1 d earlier than associated flowers, which opened independently. However, the relationships between either fruit set or growth and date of flowering did not fit our hypothesis. For example, fruits from the late flowers had the best set. Thus, the initial hypothesis should be rejected while the influence of other factors should be considered. Our observations suggest that post-bloom temperatures could affect fruit set and early growth. Key words: Peach, Prunus persica, flowering, fruit abscission, fruit growth, early stage of development