Influence of biostimulants and humic extracts treatment on the fatty acid profile of the spring oilseed rape variety

I. Petrova1, S. Ivanova1*, S. Stoyanova2, R. Mincheva2, M. Pavlova1

1Institute of Cryobiology and Food Technology, Agricultural Academy, 1407 Sofia, Bulgaria
2Institute of Agriculture and Seed Science “Obraztsov Chiflik”, Agricultural Academy, 7000 Ruse, Bulgaria

(Manuscript received 20 May 2022; accepted for publication 22 February 2023)

Abstract. For two consecutive economic years, a field experiment was conducted with spring rapeseed hybrid Rasna. The aim is to trace the effect of phytostimulant treatment on the total fat content of rapeseed and the proportion of essential fatty acids. The application of biostimulants (organic acid and humic complexes) in the cultivation of rapeseed variety Rasna leads to changes in the fatty acid composition of the seeds. The use of biostimulants HL100, HLN 55 and TH1-20% in the first year leads to a decrease in the content of saturated by 3.5%, 1.74% and 4.7% and polyunsaturated fatty acids by 2.74%, 0.59% and 3.15% due to the higher content of monounsaturated fatty acids by 0.99%, 0.58 and 1.47%. Biostimulator TH1-10% leads to an increase in saturated by 0.06%, monounsaturated by 0.26% and a decrease in polyunsaturated fatty acids by 1.35% compared to the control group of seeds. In the second year of treatment of rapeseed variety Rasna saturated fatty acids decreased compared to the control group to a lesser extent: with the application of biostimulant TH1-10% and HLN 55 by 0.33% and 0.11%, while with biostimulants HL 100, TH1-20% and H40 their content increases by 0.97, 0.06% and 0.04% respectively. Monounsaturated fatty acids decreased in humic complexes by 0.34%, biostimulator TH1-10% by 0.72% and biostimulator TH1-20% by 0.23%. Polyunsaturated fatty acids have the highest degree of reduction when applying biostimulant HL 100-2.77%. Saturated and polyunsaturated fatty acids had a higher content in the first year of treatment in rapeseed hybrid Rasna, while the concentration of monounsaturated fatty acids increased with a high degree of confidence (P≤0.001) in the second marketing year. This, on the one hand, is due to environmental factors, and on the other – to the type of preparation for treatment. The improved fatty acid composition of the seeds makes them a suitable raw material for the production of fats and their use in feed for monogastric and ruminant animals.