MARGINAL MINERAL NUTRITION OF STRAWBERRY (FRAGARIA × ANANASSA) PLANTS GROWN HYDROPONICALLY

Strawberry plants ‘Chandler’ grown in quartz sand were induced to show deficiencies of N, P, K, Ca, Mg, S and Fe. The plants were watered with nutrient solutions at low or marginal concentration of each element. The height of the plant, leaf area and the dry weight of the steams, leaves and roots were evaluated and the symptoms shown by the plants were described. Leaf analysis were made to establish the deficiencies and optimal ranges of the nutrient concentrations. The marginal treatments of N, Ca and P showed highly significant differences with respect to the Control treatment, and were the ones that produced low values of leaf area, dry weight and height of plant. Of these, the marginal P treatment showed the most distinct differences. The leaf analysis showed that the treatments with marginal deficiencies caused a decrease in the concentration of the nutrient being studied. These results coincided with the symptoms observed. The treatments with marginal deficiencies in Ca and Fe showed significant differences with respect to the Control treatment, but their concentrations in the leaves did not reach levels sufficiently low to be considered deficient.

Resumen

Plantas de fresa ‘Chandler’ cultivadas en arena de cuarzo fueron inducidas a manifestar deficiencias de N, P, K, Ca, Mg, S y Fe. Las plantas fueron regadas con soluciones nutritivas con bajas concentraciones de un elemento mineral. Se evaluó altura de planta, área foliar, pesos secos de tallos, hojas y raíces. Además se describió la sintomatología manifestada por las plantas. También se hicieron análisis de hojas para establecer los rangos óptimos y deficientes. Los tratamientos marginales de N, Ca y P, mostraron diferencias altamente significativas con respecto al tratamiento control y fueron los tratamientos que obtuvieron los menores valores de área foliar, peso seco y altura de planta, sobretodo, el tratamiento marginal de P. El análisis foliar indica que los tratamientos con deficiencia marginal produjeron una disminución en la concentración de los nutrientes minerales estudiados en las hojas, correlacionándose con los síntomas observados. Los tratamientos con deficiencia marginal en Ca y Fe, mostraron diferencias significativas con respecto al tratamiento control pero no alcanzaron niveles tan bajos como para ser considerados deficientes.