Nutrición mineral y actividad de nitrato reductasa en cafetos afectados por deficiencias minerales

Abstract

Nitrate reduction potential was investigated in the coffee tree in relation to mineral deficiency Nitrogen, phosphorus, potassium, calcium, magnesium and sulphur deficiencies were studied on the grounds of their individual effect on the nitrate reductase activity (NRa) and chemical composition of leaves. One year old coffee trees were transplanted from the field to the greenhouse, where they were fed on nutrient solutions for four months prior to treatment initiation. After this period of adaptation, the experimental plants were subjected to mineral deficiencies and were kept under control for 100 days. NRa was measured and taken as the main parameter for treatment evaluation Since the synthesis of the enzyme is included by NO3-, a 0.5M KNO3 solution was infiltrated in the leaves in vivo in order to investigate the after-effect of treatments on the basis of their maximum nitrate reduction potential displayed by the plants under investigation. Treatment effect on the NRa was explained on the basis of the interaction with the nutrional status of the plants, as reflected by leaf chemical analysis.