Hemp (Cannabis sativa, L.) Seed Harvesting in One or Two-stage within an Italian Organic Farm

Harvesting hemp for non-reproductive seeds can be carried out using standard mechanized methods for cereals. To reduce the moisture content of hemp seeds at harvest time, two harvesting systems were compared: a conventional system involving one-stage harvesting with a wheat header; and a two-stage system involving mowing-windrowing and drying in the field, followed by harvesting with a pick-up. The study was conducted in an organic farm in central Italy, near Osimo (AN). For each of the two approaches, approximately 1,000 m² cultivated with the Codimono variety were considered. The operating times of the machines were evaluated in accordance with CIOSTA standards. Seed losses were assessed by weight using collection trays placed along the machine path. After harvesting, the moisture content of the seeds, the weight of 1,000 seeds, and the germination rate were evaluated. The operating speed and the operating efficiency of the two solutions were similar (91.2% and 90.1%, for the one-stage and two-stage approaches, respectively). The moisture content of the seeds was statistically lower for the two-stage harvesting (14.4%) than for the single-pass harvest (24.9%). However, the two-stage system had a higher percentage of seed losses owing to the lower yield.