Vetivar harvesting
Harvesting is done in between 15-18 months to get fully developed root system and high quality of oil. Harvesting earlier than 15 months after planting, the immature roots yield oil of poor quality with green earthy odour. Properly developed somewhat thicker roots, yields an oil of better quality and its optical rotation and specific gravity are higher, the odour fuller, richer, more lasting. Oils derived from older roots are usually of darker colour than the oils distilled from the younger roots. If the roots stay in ground for over two years, the yield of oil diminishes considerably as the root system tend to become woody and lose in essential oil content and the oil becomes very viscous with a dark colour but of high quality. In general the crop is harvested after 15-18 months during the dry season from December to February for best quality oil. Oil content of root starts decreasing after
20 months age considerably.
For harvesting, the moist areas are taken up first. The water logged areas become dry enough in February for digging up the roots. After February due to rising temperature, the soil become harder and makes digging very difficult. At this stage the finer roots stay in the ground, which contain more oil resulting low yield per unit area.
Characteristics to determine correct harvesting age
The roots that possess the following characteristics have good oil content. It should
1. expose a hard surface when the skin is peeled off
2. be thick, hard, long and wiry and
3. give a very bitter taste when chewed
Regards
