Growth, flowering and yield of lychee cultivars

Abstract

The main period of vegetative flushing in high-yielding lychee trees (Litchi chinensis Sonn. cultivars ‘Tai So’, ‘Haak Yip’ and ‘Wai Chee’) in seven orchards in subtropical Australia (latitude 27°S) occurred after harvest from late summer and ceased 4–6 weeks before panicle emergence in May–July. Trees did not flush during winter or spring unless flowering or fruit set failed. There was no evidence of concurrent vegetative and reproductive growth in the same shoot. There was an inverse correlation between the percentage of branches flowering and the percentageof branches flushing vegetatively in the 4–6 weeks preceding panicle emergence. Satisfactory yields were usually obtained when more than 90% of the terminal branches flowered.
Flushing did not appear to be affected by temperature and rainfall or leaf nitrogen levels. The interaction of these factors demonstrates the difficultiss in separating the effects of different environental factors on vegetative growth in lychee.