Evaluation of native populations of Cymbopogon olivieri rangelands in Khuzestan province

Cymbopogon olivieri is a perennial grass in tropical regions. This species has very high compatibility in the rangelands of Khuzestan province by benefiting from type C4 photosynthesis. This species is specific to warm areas. The variation in the habitats of this species causes differences in phenotypes and forage yield of its populations. In order to evaluate the populations of Cymbopogon olivieri species, at first, the addresses of herbarium were studied, and its habitats in Khuzestan province were identified by field surveys. Then, at the appropriate time, the seeds of seven identified populations were harvested from different habitats of the province and were planted in the Baghmalek research station and evaluated for three years (2011-2014) after establishment.  To measure the traits from each population, at the stage of spike emergence, aerial parts of plants were harvested in three plots of 3 m2 from a height of 5 cm above the ground. After counting the number of tillers and plant height, they were dried and weighed in an oven at 70 ° C for 48 hours to determine dry forage yield, aerial parts. There was a significant difference between the studied populations for dry forage yield, plant height, and the number of tillers. The highest forage yield of Cymbopogan olivieri in the third year after the establishment of populations collected from Dezful-Dez Dam, Masjed Soleiman-Bardemar and Ahvaz-Masjed Soleiman route with a production of about 110 g dry m-2 and then Shushtar -Abgah, and Dezful- Shahion with a production of about 100 g dry m-2 respectively. In terms of plant height, populations related to Dezful-Dez Dam, Shushtar-Abgah, and Dezful-Sardasht-Gavmir with a longitudinal growth of more than 50 cm were statistically superior. In terms of mean tiller number per plant, the Dezful-Dez dam population with 125 tillers had the highest and the Ahwaz-Masjed Soleiman route population with an average of 69 tillers had the lowest tiller number per plant.