RESPONSE OF WINTER RAPESEED TO BIOSTIMULATOR APPLICATION AND SOWING METHOD PART II. SEED YIELD COMPONENTS
Background. The use of natural growth stimulants is becoming an increasingly common practice in agriculture. Biostimulants favourably affect the plant growth and development and increase the resistance of plants to the adverse effects of various stress factors. The aim of the study was to estimate the effect of types of the applied biostimulators and sowing methods on the number of productive tillers, the number of pods per plant, the length of pods and the number of seeds per pod in three cultivars of winter oilseed rape.
Material and methods. A field experiment was carried out in 2013–2016 at the Agricultural Experimental Station in Zawady (52°03' N; 22°33' E) which belongs to the University of Natural Sciences and Humanities in Siedlce, Poland. The experiment was conducted in a split-split-plot design with three replications. The studied factors included: I – three cultivars of winter oilseed rape: Monolit (population cultivar), PR44D06 (restored hybrid cultivar with a semi-dwarf type of growth), PT205 (restored hybrid cultivar with a traditional type of growth); II – two sowing methods: row spacing of 22.5 cm (row sowing – sowing rate of 60 seeds per 1 m2), row spacing 45.0 cm (single seed sowing – sowing rate of 40 seeds per 1 m2); III – three types of applied biostimulants: control variant (without the application of biostimulants), biostimulant Tytanit®, biostimulant Asahi®SL, biostimulant Silvit®.
Results. The present study showed a significant effect of the types of biostimulants used on the seed yield components. Sowing methods did not cause significant changes in the seed yield components, such as: the length of pods, the number of seeds per pod. Differences between the cultivars in the pod length were statistically insignificant. Diversified humidity and thermal conditions prevailing in the years of conducting the experiment significantly affected the seed yield components.
Conclusion. Under the influence of the biostimulant Asahi SL, there was a significant increase in the number of productive tillers, the number of pods per plant, the length of pods, the number of seeds per pod compared to the control variant. In the wider row spacing there was a greater number of productive tillers and pods per plant. The long-stemmed cultivar PT205 compared to the semi-dwarf PR44D06 and the population Monolith formed more productive tillers and pods per plant, while the restored hybrids possessed significantly more seeds per pod compared to the traditional cultivar. The highest values of the examined characteristics were recorded in the growing season 2013-2014, distinguished by the best pluvio-thermal conditions during spring and summer oilseed rape development.