Yield - tonnes per hectare per year
Conservative
Fresh: 10 tonnes
Dry: 1 tonne
Oil: 10 to 20 litres
Average
Fresh: 20 tonnes fresh
Dry: 2 tonnes
Oil: 25 to 30 litres
Good
Fresh: 30+ tonnes
Dry: 3+ tonnes
Oil: 50+ litres
Harvesting
Harvesting of oregano is done both manually and mechanically depending on the size of the operation. On smaller production units and in greenhouses, it is done by hand. Fresh production: start harvesting early in the morning when the temperature is still cool. Harvesting of the fresh tips can start as early as eight weeks after planting seedlings.
Dry production: For dried oregano production, cutting can be started as soon as there are enough leaves to be harvested. The vegetative growth is trimmed just before full flowering commences when the oils are at their highest levels. The cuttings are then dried at 30°C using a forced air drier or by hanging the herbs in bushels for about 21 days in a well-ventilated area out of the sun.
Do not use air warmer than 30°C as it will cause the oils to leave your herb leaves and you will lose all your flavour and aroma. Essential oil production: The best essential oils come from harvesting and distilling the oregano leaves just before they go into full flower when the oils in the plant are at their most pungent. The second harvest of the first season generally yields more plant matter and more oils.
Storage
Fresh production: After harvesting, store fresh oregano at 1 to 2°C. The oregano can be stored for about two weeks. The relative humidity in storage should be kept above 95% to prevent dehydration. Fresh herbs lose their culinary flavour fast so it is best to market and use fresh cut oregano as quickly as possible. Dry production:
The dried leaves are packaged in airtight containers as soon as possible so they retain their colour and flavour. Keep at about 10°C. The dried oregano can also be frozen in sealed packaging. Essential oil: Store bottled essential oils in a dry, dark and cool space for about a year to 18 months after bottling. After this, the oils start to lose their potency and odour.
Pests
Mealy bugs, snout beetles, spider mites, thrips, leaf rollers, and miners.Diseases
Alternaria, powdery mildew, root rots and rust are common problems. Aromatic herbs like oregano generally have fewer pests and diseases, but it is best to follow a crop protection regime prescribed by an extension officer or agronomist.
The local chemical salesmen generally have the right programmes or could provide information on the best advisors available in close proximity to the production area.
By Louise Brodie