Effects of salinity levels on germination, number of leaves and shoot and root length of different tree species

A study has been conducted to know the relative salt tolerance of Acacia nilotica (Linn.) Willd., Azadirachta indica A. Juss., Dalbergia sissoo Roxb., Dalbergia latifolia Roxb., Gmelina arborea Linn., Leucaena leucocephala (Lam.) de Wit., Prosopis cineraria Druce and Prosopis juliflora DC. tree species. Four different salt levels, viz., 0, 2.5, 3.5 and 6.5 dS/m were artificially created in the clayey soil by employing NaCl, CaCl2 and MgSO4 in the ratio of 5:3:2. Azadirachta indica and Dalbergia latifolia tolerated salts up to 6.5 dS/m at germination stage whereas Leucaena leucocephala and Gmelina arborea appeared sensitive even at 3.5 dS/m level. Their order of performance was A. indica> D. latifolia> Prosopis cineraria> P. juliflora. The maximum number of leaves and root length was observed in Prosopis juliflora whereas Leucaena leucocephala registered maximum shoot length. Dalbergia latifolia registered minimum number of leaves and shoot length whereas Gmelina arborea registered minimum root length. The reduction in the number of leaves/plant and shoot and root length under 2.5, 3.5 and 6.5 dS/m salinity levels as compared to control condition was 19.01, 47.17 and 63.66 per cent, 27.37, 52.15 and 70.71 per cent and 18.65, 42.43 and 62.86 per cent respectively.