The effect of plantation age on the yield of some mint (Mentha spp.) varieties

This study was conducted to determine the productivity of aging plantation of some mint varieties (Mentha spp.) in Sanliurfa in the south-east of Turkey. The trial was carried out between 1994 and 1998 (5 years) and was designed as a split-plot study, with 3 replications. The M. piperita L. (Mitcham), M. piperita L. (Prilubskaja) and M. spicata (Urfa Local) varieties were used as plant material. Results obtained showed that the fresh herb yield (t/ha), dry herb yield (t/ha), dry leaf yield (t/ha), essential oil yield (L/ha) and essential oil content (%) were significantly affected by the plantation age in all varieties investigated. The yields of fresh herbs, dry herbs, dry leaves and essential oils decreased dramatically in the fourth and fifth years of harvest from the plantation as only 1 harvest could be achieved during these years.