The aim of the study was to explore the possibilities for recovery of young cucumber plants grown under nitrogen deficiency by treatment with the N-extra foliar fertilizer. The experiment was carried out with cucumbers, cultivar Gergana. The plants were grown on full-strength Knop nutrient solution and the other on the same solution without nitrogen.
The results demonstrated that the N-extra foliar fertilizer improved the growth and development of the cucumber plants under nitrogen deficiency. The leaf-gas exchange increased as well as the photosynthetic pigment content and the nitrate reductase enzyme activity.