COMPARATIVE EVALUATION OF QUALITY PROPERTIES OF WINTER RAPESEED DEPENDING ON THE LEVEL OF FERTILIZERS AND SOWING DATE

Abstract

It is made the comparison estimation of winter rapeseed quality properties depending on the fertilization level and sowing date in this article. The literature on the research problem is elaborated; there are presented the study importance and relevance of growing technology elements influence on the quality properties of winter rapeseed seeds. It is analyzed the results of sowing periods and different rates of mineral fertilizers influence on the quality indicators of winter rapeseed seeds under the conditions of Right-Bank Forest-Steppe in Ukraine. Significant influence of the studied elements of technology on the main indicators of seed quality was noted; it was found that the change in the yield level obtained by the hybrids led to a change in the oil quality indices. Four the most important oil quality indicators were analyzed in this article. They are: acid value, glucosinolates amount, oil and protein contents. They were affected by different fertilizer rates and sowing dates, which were the experiment conditions. So, the lowest acid value – 1.08 provided hybrid Excel, when fertilizer rate was N240P120K24; when sowing dates were analyzed, the lowest indicator – 1.24 was obtained by Exagon hybrid in the first sowing date – 10th of Aug. the correlation between acid value and rapeseed yield was negative and oscillated from r = - 0.9327 to r = - 0.9843; the magnitude of the approximation reliability oscillated in the range of R2 = 0.87 – 0.97, which evidence the strong dependence between indicators. The lowest content of glucosinolates – 12.51 μmol / g had Excel hybrid under the conditions without fertilizers; when sowing dates were analyzed, the lowest indicator 15.06 μmol / g was obtained by Exagon hybrid in the first sowing date – 10th of Aug. The highest oil content had Excel hybrid – 46.27%, it was obtained in variant of N240P120K240. The protein content of each hybrid was increasing with fertilizer rates expansion. So, the highest indicator of it was obtained in the variant where N240P120K240 was used and it was Exagon – 22.10%. The highest protein content – 21.13% was obtained by Excel hybrid in the second sowing date – the 21st of Aug. when sowing dates were analyzed, and the highest oil content – 46.75% were obtained by Excel hybrid in the third sowing date – 5th of Sept. Key words: winter rapeseed, sowing dates, fertilizers, acid value, glucosinolates amount, oil and protein contents.