Response of turmeric to saline water irrigation on growth, physiology, antioxidant defence mechanism and productivity

Abstract

Aim: The aim of the present study was to study the effect of saline water irrigation on growth, physiology, biochemical signal and economic yield of turmeric. Methodology: Pot experiment was conducted with five salinity levels (0 dSm-1, 2 dSm-1, 4 dSm-1, 6 dSm-1 and 8 dSm-1) replicated four times in RCBD. Salinity level were prepared using NaCl, CaCl2, MgCl2 and MgSO4 to maintain Cl:SO4 ratio in 7:3. Salinity treatments were imposed according to treatment scheduled 30 day after transplanting of seedling and continued till crop maturity. In each pot 2 l of saline water was applied at 10 days interval according to the treatment. The control plants were irrigated with equal amount of distilled water. Observations on morphological, chlorophyll, canopy temperature, Normalized difference in vegetative index, phenol and protein content Ascorbate peroxidase, Superoxide dismutase and yield parameters were recorded. Results: The results showed that irrigation with saline water induced changes in growth and yield parameters in turmeric crop. Plant height at different levels of salinity stress was affected significantly, the lowest (37.9cm) plant hight was observed at 8 dSm−1 salinity. A slight increase in salinity by 2 dsm-1 reduced the growth of turmeric by 15.7% as compared to control. Number of tillers, leaves per plant and leaf area was also significantly reduced. With increase in salinity levels, the chlorophyll and NDVI of leaves were reduced. The lowest fresh rhizome yield (19.8 g per plant) was recorded at 8 dSm−1 and in turn, it resulted in the lowest dry yield (2.5 g per plant) and dry recovery (12%). Interpretation: Salinity is highly detrimental to turmeric crop and leads to drastic reduction in growth, yield and productivity by reducing physiological and biochemical functions. Thus, the use of saline water in irrigation should be carefully looked inorder avoid yield loss. Key words: Chlorophyll, Dry recovery, Membrane stability, Salinity, Turmeric