- S A Oosthuyse
- HortResearch SA, PO Box 3849, Tzaneen 0850, South Africa
- 2007
A Group of Mauritius litchi trees was pruned on each of a number of dates during January, February and March, 2006, for the purpose of effecting uniformity of terminal shoot and development stage at various times prior to the flowering period in June-July. Flowering intensity as it relates to the stage of terminal shoot maturation in late May, just prior to the flowering period, was in this way assessed. Flowering intensity was greatest in the trees pruned on Feb. 2 or 16. The terminal shoots on these trees were at an advanced stage of maturation on May 29. In the trees pruned on Jan. 19, terminal shoot maturation was such that the stage of readiness of the apical buds on the terminal shoots to break occurred before conditions had become inductive, this resulting in new shoot development occurring prior to the flowering period. Pruning later than Feb. 16 was apparently such that the terminal shoots were not mature enough for general apical bud break to occur when conditions were inductive. Apical bud development occurred to the greatest extent when conditions were inductive in the trees pruned on Feb. 2 or 16. Number of fruits retained per inflorescence appeared to bear in inverse relationship with tree flowering intensity. However, the relationship was such that fruit yield and flowering intensity were positively related. General pruning of Mauritius litchi trees is required to prevent canopy overcrowding. The results of the current study clearly indicate that the date of pruning is vital regarding tree-capacity to flower. Early February pruning is strongly indicated to maximize the likelihood of a general flowering. Further research may be necessary to determine whether early February pruning is suitable for warmer or cooler regions, or during differing seasons in the region where the study was carried out.
Summary:
The study investigated how pruning dates post-harvest (January to March) affect terminal shoot maturation, flowering intensity, and fruit yield in Mauritius litchi trees.
Trees pruned on February 2 or 16 showed the greatest flowering intensity, with terminal shoots at an advanced maturation stage just before flowering in late May.
Early pruning (January 19) led to premature shoot maturation before inductive conditions, causing new shoot growth instead of flowering.
Pruning later than February 16 resulted in terminal shoots that were not mature enough for apical bud break when flowering conditions became inductive.
Flowering intensity positively correlated with fruit yield despite an apparent inverse relationship between fruit retention per inflorescence and flowering intensity.
Pruning synchronizes bud break and shoot development, which affects uniformity and intensity of flowering.
The study highlights the importance of pruning timing to maximize flowering and yield, recommending early February pruning for Mauritius litchi trees.
Further research is needed to verify if early February pruning is optimal in different climates or seasons within the region.
General pruning is also necessary to prevent canopy overcrowding in mature orchards.
The results emphasize that terminal shoot maturation stage prior to flowering is critical for flowering capacity and intensity.