Key points of cultivation techniques of Roselle

Roselle is Malvaceae Hibiscus, is an annual herb, originating in Sudan, Africa. Its purple stem, green leaves, yellow flowers, red fruits, gorgeous color, is currently the world's most ideal natural plant health drinks, seeds can be extracted oil, medicinal value is very high, but also edible, stem can be used as feed and fuel, can be described as a whole treasure. In order to study this technology, Hongta District Agricultural Technology Station introduced Roselle for planting in 2011 and achieved success. The technology is introduced as follows: I. Soil requirements: Roselle is a plant that is afraid of flood and drought, and should be planted in sandy loam with sunny, deep soil layer and good drainage. 1000- 1500kg farm manure is applied per mu. II. Planting density: According to soil fertility, plant spacing: (0.6×0.8) cm, sowing 1300-1500 ponds per mu is appropriate. 3. Sowing time: Soak seeds for 12 hours before sowing, sow from mid-late April to early May, and sow 3-4 seeds per pond; transplant seedlings in nutrient pots, transplant in time when the seedlings are 12-15 cm high. 4. Field management: 1. Timely pest control: 5-7 days after sowing, spraying with 2.5% beta-cyhalothrin 50ml/mu to control pests. Control of root neck rot: 5% Baodining 5g, 2% kasugamycin 30ml and 15kg water were used to drench roots twice. Pesticide spraying must be carried out before flowering. Pesticide spraying is strictly prohibited during flowering to avoid drug poison remaining in calyx and affecting product quantity. 2. Timely thinning, seedling fixing and pruning: when the seedlings grow to 10-15 cm, they should be thinned, weak seedlings and sick seedlings should be separated, only one strong seedling should be left in each pond, and the rest should be allocated to supplement the pond. The thinning of seedlings should not be too late, otherwise the growth of seedlings will be affected. When the seedlings are 80 cm high, they should be pruned to promote strong branches, flowers and calyx fertilizer. 3. Fertilization and irrigation: Roselle does not need large amount of water and fertilizer, but the land with poor soil fertility and poor seedling growth should be appropriately applied with fertilizer, 20kg compound fertilizer, 8kg urea and 5kg zinc fertilizer per mu shall be applied for seedling promotion; 30kg compound fertilizer and 20kg potassium sulfate per mu shall be applied before flowering to meet the needs of flowering. 4. Intertillage, weeding and drainage: plant height 30 cm, combined with topdressing and soil cultivation, intertillage 2~3 times in due time. In summer, due to much rain and overgrowth of weeds, artificial weeding should be carried out to avoid competing with roselle for fertilizer water. In rainy season, attention should be paid to digging ditches and draining water to prevent and control the occurrence of dead seedlings and root rot. 4. Harvesting and drying Roselle is mainly to harvest sepals. In the middle and late October, the seeds in the flower bag become hard or brown. In sunny days, cut off the fruit branches with scissors, pick off the calyx together with the fruit, dry it for one day first, and take off the calyx after shrinking. When removing the calyx, use a pen to cover the metal tube with the diameter of the diameter, support the fruit base, push out the round fruit, separate the calyx from the fruit, keep the calyx intact, and do not break it off. Then place it in a clean place and cool it with utensils. or dried at 40℃. Roselle is acidic and easy to mold. It should be dried in time.