Polygonum weyrichi (Gorset Weyrichi) – a perennial rhizomatous plant of the buckwheat family, reaching a height of up to 2–2.5 m and forming large rhizomes during the third–fourth year. Seeds ripen after harvest and require a post-harvest ripening period; for spring sowing, stratified seeds are recommended or plantations should be planted using rhizome cuttings.
The 'Syktyvkarets' variety is distinguished by high productivity, reaching 350–750 c/ha in the third–fourth year of life. In 100 kg of green mass, there are about 13.5 k. units and 2.4 kg of digestible protein; when silage is made – 12 k. units per 100 kg with 126 g of digestible protein per unit. Green mass is better silaged in combination with carbohydrate crops (corn, sorghum), as well as used for preparing silage and grass meal.
Plantations are placed on fertile soils with pH 5.5–7.0; optimal sowing depth is 1–2 cm, rate is 6–7 kg/ha. Row spacing is 40–60 cm. Harvesting of green mass is carried out at the budding stage (first cut) and mass flowering (second cut), while seed harvest is done at 70% fruit ripeness. It is recommended to annually add 15–20 t/ha of rotted manure and also maintain the nitrogen, phosphorus, and potassium balance for optimal plant growth.
