versión impresa ISSN 0103-9016
RUSCHEL, Jonas et al. Leaf nutrient contents of rangpur lime rootstock as afected by N, P, K, Ca and S fertilization. Sci. agric. (Piracicaba, Braz.) [online]. 2004, vol.61, n.5, pp. 501-506. ISSN 0103-9016. http://dx.doi.org/10.1590/S0103-90162004000500007.
Analysis of leaf nutrient contents can demonstrate plant nutritional status, identify symptoms of deficiency and toxicity, and evaluate the need to adjust fertilization programs. This research determined N:P:K:Ca:S rates for optimal nutrition of Rangpur lime - RL (Citrus limonia Osb.) rootstock, in an experiment arranged in a fractional factorial design of the (1/25) 54 type, with 25 treatments distributed within five blocks. Seedlings of RL were transplanted into 3.8-dm3 containers filled with commercial growing media, when plant height = 10 cm, in a nursery. Treatments consisted of the following nutrient rates (g per plant): N = 0.31, 0.62, 1.25, 2.5 and 5; K = 0.4, 0.62, 1.25, 2.5 and 5; P = 0.35, 1.0, 2.0, 3.0 and 4.0; and Ca = 3.5, 5.0, 6.0, 7.0 and 8.0. Phosphorus and Ca were applied to the compost before transplant of seedlings, while N and K were applied later and total amounts were split into 20 weekly applications via fertigation. Nutrient sources were triple super phosphate, gypsum, NH4NO3 and KCl. Leaf nutrient concentrations of five-mo-old plants were high or in excess for N, P, K and S. Calcium and Mg concentrations were low. Greater dry mass of plants were observed at nutrient rates of N = 3.5, P = 2.7, K = 2.0, and Ca = 6.5 g per plant.
Palabras llave : Citrus limonia; mineral nutrition; leaf analysis; response surface.