Effect of salinity and population variability on growth and biomass traits for salinity tolerance in Sagwan (Tectona grandis L.)

Sagwan is one of the most valuable and planted tree species in India and abroad. Teak (Tectona grandis L.) belongs to Lamiaceae family which is also called as “King of Timber” due to its wood quality and durability across the world. In the present time, salinity in soil is increasing in India and global level. There is need to identify the good genotypes of teak which are tolerant to salinity. Therefore, the present study was carried out in Forest Nursery at College of Forestry, Navsari Agricultural University, Navsari. The seed material of Sagwan collected from five different populations viz., Bhenskatri, Junagadh, Padamdungari, Subir and Waghai, and sown in Forest Nursery. Plants were grown for two months in pots before starting the treatments with regular watering and thereafter, four salt stress treatments along with a control was induced through irrigation with a range of diluted sea water (EC 1 dS/m, 2 dS/m, 4 dS/m and 6 dS/m). The study revealed that there was large variation for growth and biomass traits among all the population and salinity levels. It was found that the plant growth and biomass of Sagwan in early stage was reduced when the salt concentration increased. In addition, Bhenskatri population was performed better among all the five populations for biomass and growth traits at all five salinity levels. However, all five populations of teak survived under continuous supply of saline water and the detrimental effect of salt was evident at higher dose (EC ≥ 4 dS/m). Interesting to see that Bhenskatri population does not compromise for growth and biomass traits under salinity which should be further explored for further improvement of teak for salinity resistance. Thus, Bhenskatri population was recommended for plantation purposes in the salt affected areas in south Gujarat region of India.