• Józef Sowiński Institute of Agroecology and Plant Production, Wroclaw University of Environmental and Life Sciences Grunwaldzki square 24a , 50-363 Wroclaw, Poland
  • Agata Liszka-Brandau Control Union Poland Sp. z o.o. in Zielona Góra Wojska Polskiego 45, 65-764 Zielona Góra, Poland


Background. Field studies carried out at Pawlowice Research Station near Wroclaw in the years 2006–2008. Research aimed at the comparison of the morphology of the internodes of two sorghum hybrids: Sucrosorgo G–1990 (photoperiodically sensitive – headless) and Sucrosorgo 506 (photoperiodically insensitive – headed).  
Material and methods. Stem with small and large diameter were collected separately from both hybrids. The effect of the place from which the internodes were collected (lower, middle, upper part of stem) on morphological features was determined. The length, mass and the diameter of stem were specified. The morphological measurement of internodes were identical for whole material and the content of leaves, rind (outer internode part) and pith (inner part) in dry matter was determined.
Results. The headed hybrid of sorghum was taller (by 29.7%) and had higher mass (by 40%) but lower diameter (1.83 cm) than the photoperiodically sensitive hybrid. The lower internode was shortest (13.2 cm) while longest one was collected from middle part of stem (19.7 cm). The lowest mass (35.2 g) and the smallest diameter (1.7 cm) has upper internode. Stem with larger diameter had shorter internodes (by 5.0 cm), higher mass (by 36.3 g) and larger diameter (by 0.8 cm). In the lower internodes dry matter content was highest. In the headed hybrid, the percentage of pith was the highest in the lower internode (44.3% – large diameter stem and 45.0% – small diameter stem). In the lower internode of the photoperiodically sensitive hybrid the rind dominated (42.8% dry matter from large diameter stem and 42.5% dry matter from small diameter stem).
Conclusion. Pith part content constituted 39.9–42.8% of internode dry mass and depends on place from the internode was collected. The rind dominated in the lower part of the stem.

Aug 23, 2018
Original paper