Determination of phosphorus status on duku (lansium domesticum) seedling

Abstract

Phosphorus, one of the major plant nutrients that is a constituent of plant cells, is essential for cell division and the development of its growing tip. Symptoms of P deficiency or excessive can be seen mainly in the leaves. The sign can be detected visually and can be done by identifying P concentration in each condition. The P status study was conducted in Jambi Provinces, which was applied to duku seedlings planted in sand culture. The study was conducted in randomized complete block design, with five treatments consisting of three plants, each treatment, and three replications. The treatments consisted of five P levels: 0, 50, 100, 200, and 400 ppm. The results showed that P deficiency symptoms were characterized by stunted growth of seedlings, green-brownish and lusterless discoloration, the number of leaves < 4.56, and leaf P concentration < 0.09% (very low nutrient status) and 0.09 ≤ P < 0.14% (low nutrient status). Normal growth, shiny green leaves characterized the sufficient P concentration, number of leaves 4.56-7.00, and leaf P concentration of 0.14 ≤ P < 0.25% (medium nutrient status). Symptoms of excessive P was showed by stunted growth of seedlings, green leaves with yellow and necrotic spots on the leaf blade, the number of leaves < 4.56, P concentrations in the leaf ≥ 0.25% (high and very high nutrient status). The maximum growth of duku seedling for very low nutrient status was 195 ppm P, equivalent to 115 g SP-36/year or 58 g SP-36/6 month.