Rosemary is a dense evergreen undershrub with lavender-like leaves and a characteristic aroma. Of Mediterranean origin, it is indigenous to South Europe, Asia Minor and North Africa. It is cultivated in Spain, Tunisia, Yugoslavia, France, Italy, North Africa and India (in Nilgiris). The key markets for Rosemary are U.S.A and Europe.
Rosemary Rosmarinus officinalis L. belongs to the family Labiatae (Lamiaceae). It is an evergreen dense highly branched herb or undershrub that grows up to 1m in height. The long slender branches bear many sessile opposite leaves, smooth and green on one side and woolly whitish and glandular beneath , 2-4 cm long, almost cylindrical and folded inwards; the flowers are situated in small clusters towards the ends of the branches; the calyx is two-lipped, with an upper single broad oval lobe and a lower two-segmented triangular lobe; the corolla is two-lipped with two violet stamens and a long style projecting from it and the fruit is an oval 4-sectioned cremocarp.
Mediterranean climate best suits Rosemary, however it adapts well to most climates. It is susceptible to frost injury. In cooler areas, it is usually cultivated in the summer season. It requires light dry soil, preferably lying over chalk. Neutral to alkaline pH is most suitable. The plant is propagated through seeds and vegetatively, by cuttings, the latter being generally adopted. Ideally, the cuttings should be 15 cm long, with the leaves removed from the basal half portion. These cuttings are then put in nursery beds of sandy soil at a depth of about 10 cm. The main field is prepared incorporating 10-15 tons/ha of organic manures. The rooted cuttings are transplanted in rows, 120 cm apart with a plant to plant spacing of 30-40 cm. Fertilisers are applied at 100:40:40 N, P2O5 and K2O/ha; N being applied in 4-5 split doses during each year. Well drained soil is most suited to the plant and irrigation is needed only when the soil is completely depleted of water. Intercultivation keeps the soil loose and clean from weeds and promotes proper plant growth and development. Phytocoris rosmarini sp. nov. and Ortholylus ribesi sp. nov. have been known to infest rosemary crops. Rosemary shoots are ready to be cut for distillation when it reaches maximum size, before it become woody. The hard wood imparts an undesirable turpentine odour to the essential oil. Harvesting is usually done in the months of May and June. Frequent cutting of the bushes every 2-3 years keeps them from becoming leggy and promotes the formation of numerous young shoots.
Post Harvest Technology
Harvesting is done at the beginning of the flowering season. Rosemary that is planted in the field in June – July will be ready for harvesting the following January – February or even earlier, if the weather conditions are favorable and promote adequate growth. Care should be taken to avoid woody and foreign materials during harvesting. It is necessary to ensure that the bushes are avoided as the plant is kept alive by the leaves present in the lower portion of the bush. Usually, there is a single harvest in the first year, followed by three harvests in the subsequent years. A yield of 11.0 -15.0 Mt / Ha fresh leaves or 2.8 – 3.7 Mt / Ha dried leaves can be obtained per annum.