The impact of foliar feeding on the yield components of three winter rape morphotypes (Brassica napus L.)

The aim of the study was to determine the impact of foliar fertilizers containing amino acids, sulphur, boron on the number of productive branches, the number of pods per plant, the number of seeds in pods and the length of pods of three winter rape (Brassica napus) varieties (Monolit, PX115, PT248). The research was carried out in 2016-2017, 2017-2018, 2018-2019 at the Zawady Agricultural Experimental Station (52o03’N and 22o33’E) belonging to the University of Natural Sciences and Humanities in Siedlce, Poland. The field experiment was set up in a split-plot layout in triplicate. The area of one plot for harvest was 21 m². The examined factors were I - morphotipe of winter rape: population variety (Monolit), hybrid restored with a semi-dwarf growth type (PX115), hybrid restored with a traditional growth type (PT248). II - types of foliar feeding: 1. treatment without biostimulator and foliar feeding, 2. Bioregulator Aminoplant, 3. Foliar fertilizer Siarkomag with foliar fertilizer Bormax, 4. Foliar fertilizer Siarkomag with foliar fertilizer Bormax and Aminoplant. Variable climatic conditions in the years of the experiment affected the studied components of seed yield of three L. morphotypes. In the year 2016-2017 of research, the plants produced the most productive branches, had the longest pods filled with the largest number of seeds. Foliar nutrition with a biostimulator containing amino acids did not significantly affect the increase of the number of productive branches, pods per plant and pod length compared to the variant on which no foliar fertilization was applied. Foliar fertilization with S and B in combination with bio-stimulators was the most effective in increasing the components of seed yield, while the number of productive branches and length of pods under the influence of foliar fertilizers was the same regardless of the application of the biostimulator. The long-stem variety had longer pods that were filled with more seeds than the others.