MEDICINAL AND AROMATIC CROPS (2+1)

Harvesting and yield

Flowers are ready for harvest in about 3 to 3½ months of planting. August-September is the peak period of flowering. Depending on the purpose, harvesting is done by cutting the fully-opened spikes from the base or single flowers are harvested as they open by day; the picking of individual flowers should be completed by 8.00 a.m. The flowers have a shelf-life of 3 days. About 17-18 t/ha flowers can be expected from a well-maintained garden.

About 150 kg of flowers are required to produce 1 kg of concrete. The extracted flowers will contain some natural perfume and are treated with petroleum ether to obtain the absolute of chassis as a valuable by-product (yield 1.2-1.5%). In recent years, the process of Enfleurage has been partly replaced by solvent extraction, which requires much less labour though the yield of the absolute reduces considerably. The extrac¬tion of the tuberose flowers with petroleum either yields 0.08-0.11 % of concrete, which gives 18-23% of absolute on treatment with alcohol. The concrete yield is about 17-18 kg/ha which gives 3.5 kg absolute and 0.8 kg distillable oil.

Ratoon cropping
After harvesting the main crop, the flower stalks are headed back (cut to the base) and the plots are manured and irrigated. About 3-4 ratoon crops can be taken from a single planting.