Effect of Sunflower Fertilization with Increasing Nitrogen Rates at Different Seeding Terms

M. STAMBOLIEV and M. ANGELOVA
Institute of Corn, BG-3230 Kneja, Bulgaria

Abstract

STAMBOLIEV, M. and M. ANGELOVA, 2001. Effect of sunflower fertilization with increasing nitrogen rates at different seeding terms. Bulg. J. Agric. Sci., 7: 441-444

The efficiency of increasing nitrogen rates in the fertilization of sunflower grown on carbonate chernozem in Northwest Bulgaria is expressed better during years, favorable for its development, at earlier time of seeding.
In years, unfavorable for sunflower development, no fertilization effect can be expected.
With the same phosphorus-potassium background, the hybrid Albena responds better to increasing nitrogen fertilization rates compared to Cv. Peredovik.

Key words: fertilization, seeding terms, sunflower development, correlation coefficients, regression coefficients