Fertilizing Lychee Plants with Phosphorus at Time of Planting in Brazil

The objective of this research was to study the effects of P fertilizers applied at time of planting on lychees’ nutritional status and on plant growth. The treatments consisted of five doses of P: zero, 50, 100, 200, and 300？g of P2O5 per plant, furnished by triple superphosphate. Plant diameter was evaluated during two years and the plants’ nutritional status on the second year. The second year foliar levels of macro and micronutrients (with the exception of Zn) were increased by the P fertilizer. The orchard’s initial development, especially during the second year, was also influenced by the fertilizer. The P doses of 164 and 158？g of P2O5 per plant resulted in the largest plant diameter after the first and the second year, respectively. These doses were found to be associated with a foliar P level of <1.4？g？kg？1. 1. Introduction The demand for fruits has been growing all over the world in recent years due to growing awareness of the importance of a well-balanced diet for human health purposes. Thus, increasing fruit production has become an important item in the agenda of farmers in general. Lychee (Litchi chinensis Sonn) is one of the fruits the consumption of which has been growing steadily in recent years. Lychee, a fruit tree originated in China, was introduced in Brazil in 1810 [1]. Brazilian soils are, usually, of low fertility. Menzel and Simpson [2] investigated several factors capable of causing lychee plants to produce poorly and concluded that the plants’ nutritional status was one of the most important. Ghosh [3] also considered plant malnutrition as the most important reason for poor productive performance of lychee. Phosphorus is one of the most important productivity-limiting nutrients due to its role in plant metabolism. Reports by Koen et al. [4] and Vilela and Anghinoni [5], indicate the importance of P in productivity of lychee plants. Rai et al. [6], working on Alfisol (3.2？g？ha？1 of P, using a Bray I extractor) in China, showed that 220？g of P per lychee plant caused the plants to grow and produce more. They also observed a significant correlation between fruit production and P level in leaves. In an Australian study, Menzel et al. [7] suggested that the adequate level of P in leaves for a good production was between 1.4 and 2.2？g？kg？1, as measured in branch leaves after panicle emergence in the period between May and August. Martins et al. [1] recommend 0.11 to 0.22？kg of fertilizers containing 2–4% of P for lychee plants in their first year of cultivation. In Hawaii, a recommendation of 78？g of P2O5 per lychee plant is