EXPRESSION OF NUTRIENT DEFICIENCIES OF NITROGEN, PHOSPHORUS, POTASSIUM, SULFUR AND IRON IN AGAVE ANGUSTIFOLIA HAW.
In order to determine the symptoms of nutritional deficiency and mineral concentration in Agave angustifolia Haw. plants, a pot experiment was conducted using sand and plants of one year of age. Treatments were irrigation during twelve months with complete formulation of Steiner nutrient solutions and lacking in N, P, K, S and Fe. Phenotypic variables were evaluated by measurements and direct observations; minerals were analyzed on a dry basis, N by microkjeldahl method, P by colorimetric method with vanadomolibdic reactive, S by turbidimetry, and K and Fe by atomic absorption spectrophotometry. Taking as reference the plants that received complete solution, it was observed that plants without N showed a general yellowing, fewer leaves, smaller stem diameter and fewer tillers; plants without P showed small basal leaves with dark blue-green tonality with bronzed or purple dyes; where K was missed the plant showed a slower growth, followed by necrosis on tips and edges of basal leaves; plants without S had a premature development of lateral buds and there were no symptoms; plants without Fe had yellow spots in the base of the leaves together with necrotic spots and edges. In general, mineral concentration was significantly higher in leaves (N 1.12%, P 0.02%, K 1.22%, S 0.18%, and Fe 0.03%) and stem (N 0.88%, P 0.08%, K 4.98%, S 2.01%, and Fe 0.04) of plants with complete nutrient solution, with respect to those plants that received nutrient solution with a missing element. The stem showed higher nutrient concentration than leaves in P, K, S, and Fe, and only N was higher in leaves and lowest in the stem.
Ruiz-Luna, J., Velasco-Velasco, V.A., Maldonado-Peralta, R., Enríquez-del Valle, J.R., Campos-Ángeles , G.V., Rodríguez-Ortiz, G. and Preciado-Rangel, P. (2012). EXPRESSION OF NUTRIENT DEFICIENCIES OF NITROGEN, PHOSPHORUS, POTASSIUM, SULFUR AND IRON IN AGAVE ANGUSTIFOLIA HAW.. Acta Hortic. 947, 339-345
deficiency symptoms, mineral nutrition, absence of nitrogen