Pruning to control tree size, flowering and production of litchi

• The effect of pruning on the growth of litchi was examined in Australia.
• Trees were pruned after harvest and at the time of flower initiation.
• The optimum time of pruning varied with the climate at each site.
• These results can be applied to other growing areas.
• There are different optimum times of pruning for trees in warm and cool areas.

We investigated the effect of hedging on the yield of ‘Kwai May Pink’ litchi (Litchi chinensis Sonn.) trees over 4 years at three sites in eastern Australia. Individual trees in these orchards were pruned at various times to remove 0.5–1.0 m of the terminal branches. At Brooklet in northern New South Wales, at the southern end of the commercial range of the crop, the optimum time of pruning appeared to be in early- to mid-February, but this was before the previous crop was harvested. Trees hedged in early March had virtually no crop since most of the branches did not complete a flush of growth before the normal time of floral initiation in winter. In Bundaberg in southern Queensland, this was not an issue, and good yields followed hedging in late February or early March in 3 out of 3 years. In Mareeba in northern Queensland at the northern end of the commercial range, hedging in mid-March was highly variable, with good yields in 1 out of 4 years and poor yields in 3 out of 4 years. The optimum time of pruning appeared to be in early January or early March in this area, which would allow the completion of two or one growth flushes before winter. There is the added problem in this environment that the trees may not flower every year because the warmer conditions provide only a short window for floral initiation. Trees at Bundaberg and Mareeba hedged in May or June just before the normal time of floral initiation flowered but cropped poorly compared with control trees. The results of this study confirm the strong relationship between flowering and shoot development in litchi. They also support the idea that the developing fruit are dependent on current photosynthates produced by the leaves behind the inflorescences. Suggestions are provided on options for pruning litchi trees growing in different environments, including warm tropical areas, warm subtropical areas, and cool subtropical areas.