K. KOSTADINOV and S. KOSTADINOVA
Agricultural University, BG - 4000 Plovdiv, Bulgaria
KOSTADINOV, K. and S. KOSTADINOVA, 2014. Nitrogen efficiency in eggplants (Solanum melongena L.) depending on fertilizing. Bulg. J. Agric. Sci., 20: 287-292
A field fertilizer test was carried out on the experimental field of the Department of Horticulture at the Agricultural University in Plovdiv with the Patladzhan 12 eggplant cultivar grown on mollic fluvisols (FAO, 2006) as a mid-early field production over the three-year period of 2004 – 2006. The separate effects of two levels of soil fertilization (N120P60K60 = Т1 and N240P120K120 = Т2) were studied, as well as their combination with four foliar sprays (Fitona, Hortigrow Universal, Agroleaf Total and Kristalon Special), applying the following scheme: 1. T0; 2. T1; 3. T1+Fitona; 4. T1+Hortigrow; 5. T1+ Agroleaf; 6. T1+ Kristalon; 7. T2; 8. T2+Fitona; 9. T2+Hortigrow; 10. T2+Agroleaf; 11. T2+Kristalon. The experiment was done with four replications. The agronomic N efficiency as a result of the foliar feeding with Fitona 1, Hortigrow, Agroleaf and Kristalon decreased with the increase of the level of soil fertilization of N120P60K60 на N240P120K120 and was insignificantly dependent on the type of foliar fertilizer. The obtained results showed that the tested foliar sprays compared with the two levels of soil fertilization increased the NREC compared with the unaided soil fertilization on the average for the period. Both the fresh and dry yields were significantly and positively related to the nitrogen harvest index and the N export during maturity. A considerable negative relation was established between the fresh fruit yield of the eggplants and the physiological nitrogen efficiency. The agronomic efficiency of nitrogen was strongly and positively related to the physiological and recovery efficiency as well as to the nitrogen harvest index.