The objective of this work was to adjust the critical nitrogen (N) dilution curve of the potato cultivar Asterix and to evaluate its use on N management strategies. Tubers of this cultivar were planted in 5 dm³ polyethylene bags filled with organic substrate in the density of 4.4 bags m-2. Treatments consisted of five nutrient solutions with N concentrations of 5, 8.3, 11.3, 14.3, and 16.3 mmol L-1. Other macronutrients as 8.3 of K+, 1.75 of Ca2+, 1,2 of H2PO4-, 0.7 of Mg2+, 0.7 mmol L-1 of SO4(2-) and micronutrients were added in standard concentrations. Dry matter and N concentration in leaves, stems and tubers were weekly determined, from 43 to 99 days after planting. The critical nitrogen curve [N (g kg-1) = 36DM-0.37] was adjusted, based on total dry matter production. This dilution curve may be used as an interpretation tool for foliar analysis results and as a parameter to estimate N extraction during growth and development of the potato cultivar Asterix.
Solanum tuberosum; allometry; fertilization; dry matter
