C.M. Menzel, D.R. Simpson, G.F. Haydon
Six year-old lychee trees (cv. Bengal) were uprooted and dissected into nine vegetative organs just after panicle emergence in July and fruit harvested in January for N,P,K, Ca and Mg concentration. The above ground organs accounted for nearly 90% of the trees vegetative dry matter. Within the vegetative shoot, the leaves, twigs (<1 cm diameter) and small branches (1–3 cm diameter) were the most important organs (65% of shoot weight). Concentrations of most nutrients were highest in the leaves and fell with age of the organs to reach minimum values between the twigs and medium roots (0.5–1.0cm diameter), and then rose in the small roots (<0.5cm diameter). The only exception was P which was highest in the twigs. About 50% of the trees nutrients (vegetative organs) were in the leaves, 8% in the twigs and 16% in the small branches. The amounts of N, P and K present in the fruit (average yield of 50 ± 8.5kg/tree) represent 43–88% of the total for a tree harvested before flowering, compared to <25% for Ca and Mg. These results suggest that the leaves, twigs and small branches are the large pools of nutrients in the tree. Mobile nutrients such as N, P and K should be applied well before fruit set to build up tree reserves for flowering and fruiting. Less mobile nutrients will probably need to be supplied during the flowering and fruiting season.
Menzel, C.M., Simpson, D.R. and Haydon, G.F. (1992). PARTITIONING OF NUTRIENTS IN BEARING LYCHEE TREES (LITCHI CHINENSIS SONN). Acta Hortic. 321, 535-540
DOI: 10.17660/ActaHortic.1992.321.60

Acta Horticulturae