Evaluation of Growth and Energy Parameters of One-Year-Old Raspberry Shoots, Depending on the Variety

Abstract

The article examines the influence of six varieties of primocane raspberries, Rubus idaeus L., on the growth parameters and energy properties of the biomass. The unique aim of this study was to show the impact of primocane raspberry varieties, grown for a single harvest, on the growth parameters of the bushes and the energy and emission characteristics of the biomass obtained from the pruned canes. To the best of our knowledge, there is no such analysis connected to varieties of raspberries available in the literature. The following primocane raspberries were assessed: Polana, Polesie, Delniwa, Poemat, Polonez, and Poranek. Among the studied raspberry varieties, Polana was characterized by the highest number of side shoots and the greatest sum of the shoot lengths, while the Polonez variety was characterized by the highest average shoot length and shoot thickness. In the tested raspberry varieties, the weight of the shoots per hectare varied significantly, ranging from 6.06 t in the Poranek variety to 9.05 t in the Delniwa variety. It was shown that the raspberry variety had a significant impact on the higher heating value (HHV) and the lower heating value (LHV). The lowest energy value was found in the Delniwa (HHV—17.32 MJ·kg−1; LHV—16.07 MJ·kg−1) and Polana (HHV—17.33 MJ·kg−1, LHV—16.19 MJ·kg−1) varieties, and the significantly highest value was observed in the Poranek variety (HHV—17.63 MJ·kg−1, LHV—16.39 MJ·kg−1). The assessment of the total volume of exhaust gases showed the highest value of this parameter for the Polesie and Delniwa varieties (6.89 m3·kg−1), with the lowest for the Polana variety (6.69 m3·kg−1).