RESPONSE OF WINTER RAPESEED TO BIOSTIMULATOR APPLICATION AND SOWING METHOD PART I. FIELD ARCHITECTURE ELEMENTS
Background. In plant production, reaching high and good quality yields of cultivated plants is achieved mostly thanks to the ability to counteract the occurrence of stress and the amendment of damage caused by stress. The aim of the study was to determine the effect of the applied biostimulator types and the sowing methods on the filed architecture elements of three winter rapeseed cultivars.
Material and methods. Field experiment was carried out in years 2013-2016 at the Agricultural Experimental Station in Zawady (52°03' N; 22°33' E), which is part of the University of Natural Sciences and Humanities in Siedlce, Poland. The experiment was carried out in a split-split-plot design in three repetitions. The studied factors were: I – winter rapeseed cultivar: Monolit (open-pollinated), PR44D06 (restored hybrid of semidwarf growth type), and PT205 (restored hybrid of traditional growth type); II – sowing method: row sowing (row spacing 22.5 cm, sowing density 60 seeds per 1 m2), single-seed sowing (row spacing 45.0 cm, sowing density 40 seeds per 1 m2); III – types of the applied biostimulators: control (no biostimulators), Tytanit®, Asahi®SL, and Silvit®.
Results. Research demonstrated significant effect of the applied biostimulator types and the sowing method on the biometric plant characteristics before harvest, such as: plant density, plant height, stem thickness at the base, first productive branch placement. The greatest plant height was found in the restored morphotype of traditional growth type and in the open-pollinated cultivar, whereas the highest first productive branch placement in cultivar PT205. Restored hybrids PT205 and PR44D06 were characterized by greater stem thickness at the base in comparison with the open-pollinated morphotype.
Conclusion. Biostimulator Asahi SL had the greatest effect on plant density, plant height, stem thickness at the base, and first productive branch placement, whilst biostimulator Tytanit had the lowest effect. Applied bioregulator types did not affect canopy lodging. Sowing method significantly affected stem thickness at the base, although it did not significantly affect canopy lodging. Genetic factor did not determine plant number established before harvest or changes in canopy lodging. Diversified weather conditions in the study years affected the studied elements of field architecture.