Pg. 4-5 Observation on Controlling Flowering and Tree Size in Lychee by Strategic Pruning

There is strong interest in methods of tree size control in lychee orchards in Australia. Smaller trees are easier to harvest and insect, bat and bird control are more effective. This all adds up to increased net returns for the grower. This paper reports on the effects of pruning in summer or winter or both seasons on flowering and fruit production of cultivars Bengal, Kwai May Pink and Wai Chee over a single season in subtropical Queensland, Australia. A mechanical pruner was used to shave approximately 25-30 cm of new wood from the canopy. Flowering after pruning and fruit production were reduced by about 25 per cent, compared to non-pruned trees, with trees. pruned in summer showing the best response. The long-term benefits of pruning requires further research.

Summary:

• The article addresses controlling tree size in lychee orchards through pruning to make harvesting and pest control easier and more profitable for growers.
• Pruning was tested on cultivars Bengal, Kwai May Pink, and Wai Chee in subtropical Queensland, Australia, during summer, winter, or both seasons.
• A mechanical pruner shaved about 25-30 cm of new wood from the canopy at different times of the year.
• Pruning reduced flowering and fruit yield by approximately 25% compared to unpruned trees, with summer pruning showing the best results.
• Cluster (fruit bunch) weight was generally unaffected by pruning except for Bengal cultivar after winter pruning, which showed a 50% reduction.
• The long-term effects of pruning on productivity are still unknown and require further research.
• Smaller trees from pruning could enable higher density planting (e.g., 625 trees/ha instead of 140 trees/ha), potentially increasing overall yield per hectare despite individual tree yield reduction.
• Mechanical pruning is promising for maintaining tree height around 3-4 meters and improving harvest efficiency and pest control.
• Pruning’s impact on flowering and yield showed some variation among cultivars, with Kwai May Pink being less vigorous and Wai Chee showing generally low flowering.
• The authors caution that industry recommendations await long-term studies, with ongoing research planned to assess effects over multiple years.
• Overall, strategic pruning could become an important management tool for lychee growers if long-term productivity is maintained.