Cymbopogon martinii

This grass grows fairly tall, ranging from 1.3 to 3 m (4 ft 3 in to 9 ft 10 in) in height with a pale green color and a strong thin stem. This crop grows slowly, taking three months to flower; once it has flowered, it can be harvested. It received the name palmarosa from the sweet-smelling floral rose aroma it gives off.[8] It is widely used for rose-smelling perfumes and cosmetics around the world.[9] It is also known to help repel mosquitoes and flavor tobacco products. It has been used in medicinal solutions and for aromatherapy.[4]

Palmarosa is wildly grown in wetlands in provinces of India, including Nepal.[10] The Palmarosa oil is extracted from the stem of the grass by distillation of dried leaves.[11] Once the stems and leaves have been distilled for two to three hours, to separate the oil from the palmarose, then the leftover distilled grass is turned into organic matter and becomes manure or is composted.[12]

The most efficient way to grow palmarosa is in a nursery with much irrigation and soil pH of 7-8.[13] Two or three days before planting, it is best to overwhelm the soil with water to increase soil moisture above 60% when planting the seeds. This moisture increases the germination of the seed and increases weed control in the nursery beds as well. It is also recommended to flood the soil once a month to maintain a high moisture level in the soil. Irrigation in a nursery is most important for the first 40 days. Palmarosa grass grows well in sandy texture soil with low nitrogen, sufficient phosphorus and potassium. Weeds are a problem and keeping them out of the nursery beds will increase the yield. Manual weeding must be done often and involves a well-trained eye to uncover the weeds.[14] Also, palmarosa is often intercropped to help suppress the weeds, thus increasing yields and the land efficiency. Mostly farmers intercrop with pigeon pea, also millet and sorghum work well with row or strip intercropping because palmarosa can be harvested three to four times a year.[15][12]

It is mainly used in the perfumery industry not just for the pleasant smell but also as a source of high-grade geraniol.[3] The geraniol level received from the palmarosa oil is not always the same—it depends on three factors: first being how the diphosphate is removed from the geranyl diphosphate (GPP); second the process of converting geraniol into the form of geranyl acetate; and lastly the process of converting geranyl acetate into the geranial. If these steps are done incorrectly the level of geranial will be low along with the profits.[16]

A nursery is needed or there will be poor growth yields, that may not bring any profit to the farmer and potentially the farmer could have an economical loss. This requirement increases the startup cost for farmers which some farmers are unable to pay.[15] If not grown in a nursery this will increase the weeding labour inputs by over 70% and decrease the yield. Farmers will be spending more time weeding the plots and will receive a smaller return then if they had a nursery.[17]

Palmarosa oil is an antifungal that fights against Aspergillus niger (commonly known as black mold), Chaetomium globosum (also known as moldy soil), and Penicillium funiculosum, which is a plant pathogen.[3]