Study of some biochemical parameters and productivity of Silphium L. genotypes as perspective energetic crops

Purpose. This study was aimed to determine some biochemical parameters and productivity of the gene fund of Silphium L. genus in the M. M. Gryshko National Botanical Garden of the NAS of Ukraine. Methods. Plant raw material investigated at the flowering stage (17 genotypes) and the end of vegetation (20 genotypes) of Silphium spp. 3 species and 4 cultivars studied for the content of nutrients at the flowering. Determination of dry matter, ash, calcium, nitrogenfree extractives conducted according to Hrytsaienko et al. (2003), phosphorus, protein – according to Pochinok (1976), sugars – according to Krishchenko (1983), cellulose – according to Zheng et al. (2018), lipids – according to Zamowski, Suzuki (2004). It was used productivity parameters: yield of above-ground mass, the yield of dry mass, energetic value, yield of energy. Data analyzed statistically. Results. Investigation of nutrients content showed that content of dry matter was in the range of 18.90–29.3%, protein – in the range of 8.88–23.56%, cellulose – 15.10–36.14%, ash – 8.13–12.19%, lipids – 1.83–3.97%; yield of above-ground mass – 45.0–139.0 t/ha, the yield of dry matter – 10.31–36.92 t/ha, energy value – 3933–4249 cal/g, and yield of energy – 43.81–149.27 Gcal/ha. A study of genotypes at the flowering and end of vegetation identified that the content of dry matter for all samples was in a range of 18.38–67.49%, sugars – 2.78–19.0%, ash – 3.93–11.20%, calcium – 1.68–5.99%, phosphorus – 0.14–1.21%, energy value – 3153.36– 3770.28 cal/g. Conclusions. Plant raw material of genotypes of Silphium L. spp. is a valuable source of nutrients. The content of ash, its components, energetic value, and parameters of productivity depending on genotype and stage of growth. The results allow recommending selected Silphium genotypes as perspective energetic crops in Ukraine as well as other countries.