6. Dependence between the additional grain yield and the rate of nitrogen fertilization on triticale varieties for the Plovdiv region

This study used data on yields of grain triticale grown in a three-year field trial conducted in the experimental field of the Department of Crop Science at the Agricultural University – Plovdiv. The experiment was carried out after grain maize as predecessor in four replications with experimental plot size of 15 m². The following varieties of triticale were used for the purpose of the study – AD-7291, Rojen, Sadovec, Rakita and Zaryad. Four nitrogen rates were tested – N₀; N₆; N₁₂ and N₁₈. The grain yield was determined directly from the harvested plots of 10 m² equated to a standard humidity of 13%.
Having used the data for relative grain yield and relative fertilization rates, the degree of dependency for each of the studied varieties of triticale was established at R> 0.8. The change of the relative yield along with the increased rate of nitrogen fertilization could be traced by means of the resulting dependence, thus to make possible a more accurate economic analysis and precise fertilization of the crop. The mathematical processing of the results was carried out using the specialized computer program YIELD^®.