Pyrethrum Flower Harvesting — Processing of Insecticidal Flowers in Rwanda
Method for harvesting pyrethrum flowers (Chrysanthemum cinerariaefolium) in the volcanic highlands of southwestern Rwanda. Rwanda is one of the world's leading pyrethrum producers. The flowers contain pyrethrins — a natural insecticide. This blueprint outlines the harvesting time, flower sorting, drying in sheds, testing, and packaging. Altitude: 2,000-3,000 meters above sea level.
Instructions
Know the pyrethrum plant
Know the pyrethrum plant
Pyrethrum (Chrysanthemum cinerariaefolium) is a plant that grows well in the highlands of Rwanda, at elevations of 2,000-3,000 meters above sea level.
Know the harvest time
Know the harvest time
The harvest time is very important because pyrethrins reach their peak concentration when the flowers are fully open.
Prepare harvesting tools
Prepare harvesting tools
Prepare all the tools before going to the field.
Materials for this step:
Tools needed:
Pick flowers from the plant
Pick flowers from the plant
Pyrethrum is harvested by hand only — no metal tools are used.
Tools needed:
Prevent pyrethrin degradation
Prevent pyrethrin degradation
Pyrethrins degrade very quickly when exposed to sunlight, heat, and humidity.
Materials for this step:
Prepare the drying area
Prepare the drying area
Materials for this step:
Tools needed:
Dry flowers in the shade
Dry flowers in the shade
Check the dryness of the flowers
Check the dryness of the flowers
Thresh the dried flowers
Thresh the dried flowers
Tools needed:
Separate the flower parts
Separate the flower parts
Tools needed:
Package the dried flowers
Package the dried flowers
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Tools needed:
Store flowers in the warehouse
Store flowers in the warehouse
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Prepare the field for the next harvest
Prepare the field for the next harvest
After harvesting, the field should be prepared for the next harvest within 2-3 weeks. Remove any remaining weeds or visible stones. If the soil is dry, water it slowly in the early morning or evening — do not water during the hot day as it can damage the seedlings. Apply organic fertilizer (either compost or animal manure) around each plant — approximately 100-200 grams per plant. A pyrethrum plant can produce yields for 3-5 years without being replaced, but the best harvest comes in years 2 and 3. After 4-5 years, the plant must be replanted.
Materials for this step:
Tools needed:
Understanding the value of pyrethrum on the market
Understanding the value of pyrethrum on the market
The value of pyrethrum depends on the concentration of pyrethrins in the flowers — as it turns out, a flower batch containing 1.0-3.0% of pyrethrins is the most valuable. Buyers should know that flowers harvested at the right time (fully mature) give more pyrethrins than those harvested too early or too late. Well-dried flowers (moisture below 12%) are stored better than those that are not well dried. Rwanda sells most of its pyrethrum through SOPYRWA, selling to foreign companies that make insecticides. Prices tend to change but in one year pyrethrum can reach 6-10 dollars per kilogram of extract. Good harvesting, proper processing, and good storage are what enable the farmer to get a good price.
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