I. STOEVA and T. TONEV
Dobroudja Agricultural Institute, BG-9500 General Toshevo, Bulgaria
STOEVA, I. and T. TONEV, 2003. Yield and quality performance of winter wheat variety Pliska during 15 years of cropping with different fertilization level and rotation. Bulg. J. Agric. Sci., 9: 297–303
Results are presented on the yield and grain quality of variety Pliska grown in a stationary field trial as continuous crop and two-field crop at two fertilization rates: two-field crop (rotation of wheat and grain maize) – N120P100; N180P120, and continuous crop – N120P100K40 and N180P120K80. The trial was carried out under the conditions of slightly leached chernozem at the region of DAI-General Toshevo during 1985–1999. The summarized results showed that the climatic conditions were a limiting factor with higher significance for obtaining high yield and quality grain from the variety grown under the above conditions. In some years the fertilization of the continuous crop with N120P100K40 improved grain quality to the normal level, with yield remaining at medium level. During favourable years and increased fertilization rates variety Pliska realized maximum productivity at both crop rotations and high grain quality. Fertilization to a high level corrected the negative effect of the long-term continuous crop and the two-field crop on the variety's yield and quality, regardless of the year conditions.