Effect of different chloride concentrations on yield and growth indices in tobacco plant (Nicotiana tabacum L.)

Chloride is an essential micronutrient for plants growth; however it accumulates in large amounts in tobacco plants rapidly. To evaluate the effects of chloride concentrations in irrigating water on yield and growth indices of tobacco plant which has an important economic value، an outdoor pot experiment was established in completely randomized design during 2010 crop year at Guilan Tobacco Research Center. After transplanting similar seedlings to pots، four levels of chloride (0، 16، 32، 48 mg L-1) with 3 replicates were applied during rapid growth phase for 10 weeks. Treatment with 16 mg L-1 chloride significantly increased chlorophyll content، leaf area، leaf fresh weight، leaf area ratio (LAR)، specific leaf area (SLA)، relative leaf growth rate (RLGR) and leaf area duration (LAD) and significantly decreased unit leaf rate (ULR). Increased chloride concentration in 32 and 48 mg L-1 chloride treatments caused to increased leaf water content per area (LWCA) in comparison with control group. Chloride treatments had significant effect on leaf and root fresh weight، despite they had no significant effect on shoot and root dry weight. It seems applying 16 mg L-1 chloride to irrigation water results in improvement of yield and growth indices and increasing chloride level more than this amount caused to reduction in RGR and photosynthetic area in tobacco plant.