Rita Asakaviciute, Danuta Romanovskaja, Almantas Razukas
The research was carried out at Vok? Branch of the Lithuanian Research Centre for Agriculture and Forestry in 2018-2019. The research objective was to determine the influence of relative proportion of stems, leaves and flower panicles on the formation of biomass and grain yield. The research determined that the productivity of buckwheat was dependent on the proportion of morphological elements of plants, the influence of which was different in the process of formation of biomass and grain yieldin organic and conventional agricultural systems. The dry matter yield of biomass was found to be strongly correlated with the relative proportion of stems in the morphostructure of the plants (r=0.82** in organic farming, r=0.64** in conventional farming system). The grain yield in organic farming was dependent on the relative proportion of flowers in the morphostructure (r=0.65**). For the conventional agricultural system, the buckwheat grain yield also increased depending on the relative proportion of flowers, however, the increase was statistically unreliable (r=0.47). A higher yield index and strong correlations between the yield index and morphostructural elements were observed during a drier summer.