Propagation of Saccharum spontaneum ssp. aegyptiacum by means of stem cuttings

Saccharum spontaneum ssp. aegyptiacum is a perennial rhizomatous grass that has been attracting great attention as a bioenergy crop in the Mediterranean area. In this study, an innovative propagation method by single-node stem cuttings, as alternative to the costly propagation by rhizomes, was applied in S. spontaneum. The effects of five excision times from mother plants and subsequent transplant of stem-cuttings in pots (from October 2020 to June 2021, at 2-month intervals) and four cuttings pre-treatments: no soaking (control), 24-h soaking in water (W), indole-3-acetic acid solution (IAA, 100 ppm), or indole-3-butyric acid solution (IBA, 100 ppm), were assessed upon cuttings shooting and rooting. Rooting in the control was maximized (67%) in October. Soaking in water or in IBA promoted the rate of rooting from February onwards, and the rate of shooting from April onwards. The promoting effects of IAA upon rooting and shooting were more evident in February and April. Shoot growth was greatly affected by the course of air temperature, being rather low in winter, and high in June. All pre-treatments significantly promoted shoot growth over the control, especially in April and June transplants. This study reveals that stem-cuttings may represent a useful and viable alternative to costly method by rhizomes, in the agamic propagation of S. spontaneum.