The Influence of Sowing Density and Nitrogen Fertilization on the Yielding and Main Technological Features of Some Hemp Varieties

The experiments aimed to determine the effect of sowing density and nitrogen fertilization on the panicle yield morphological features of plants in selected cultivars of fiber hemp. A three-factor field experiment in 2014–2016 at the Experimental Station of the Institute of Natural Fibres and Medicinal Plants in Pętkowo (52°20’ N, 17°25’ E, Poland) was conducted. The study included monoecious cultivar (“Futura 75,” “KC Dora” and “Tygra”), sowing density (60 germinating seeds·1 m2 and 180 germinating seeds·1 m2), and nitrogen fertilization (0, 30, 60, 90 kg·ha−1). The sowing density modified the overall length of the stem, the technical length of the stem, and the diameter of the stem, and higher values of the features mentioned above were obtained with a lower assumed plant density, i.e. 60 germinating seeds·1 m2. Nitrogen fertilization over the three-year study period did not significantly modify the yield of hemp panicles. The tested varieties differed in productivity, the highest panicle yield was found in the “Futura 75.”