Resumen

RODRIGUEZ G, Z.F; MARMOL C, L.E; MARTINEZ, J  y  MONTIEL M, M. Total and by organs accumulation of macronutrients in cassava (Manihot esculenta Crantz) plants cv `Tempranita' at Maracaibo plain. Rev. Fac. Agron. [online]. 2009, vol.26, n.4, pp.470-489. ISSN 0378-7818.

The importance of determining the total and by organs accumulation levels in order to program rational fertilizer practices, an essay was carried out by following nursery conditions at Maracaibo plain, Venezuela, in order to determine Nitrogen, phosphorous, potassium, calcium and magnesium concentrations in cassava plants (Manihot esculenta Crantz) cv. "Tempranita" at harvest, the experiment was carried out as a randomized complete design with four replications and seven plant as experimental unit. N accumulation was determined in different plant organs by micro-kjeldahl method, P by colorimetric analysis using ammonium - molibdate, K by flame photometry, Ca using EDTA, Ca + Mg titration with EDTA and Mg for difference between Ca and Ca + Mg removal was determined based on plant dry weight and nutrient concentrations. At harvest storage roots, higher level of N (33.3 g.kg^-1) and K (12.1 g.kg^-1), was found in foliar blade and the lower was found in roots; while in stems higher level the P (3.3 g.kg^-1) and the lower in roots (1.2 g.kg^-1); Ca and Mg while higher levels in petioles (30.7 and 4.1 g.kg^-1 respectively) and the lower was found in roots (2.3 and 0.8 g.kg^-1). The higher quantity elements extracted were N, K and Ca. The total extraction of plants was 288.06 kg N, 53.40 kg P, 240.24 kg K, 227.70 kg Ca and 48.94 kg Mg for a production per hectare of 59,180 kg of storage roots.

Palabras clave : Manihot esculenta; accumulation; nutrients; tissue analysis.