Tolerance of Tobacco (Nicotianatabacum and N. rustica) to High Rates of Lead Application to the Soil

Eight genetically diverse tobacco types (Tsebelia of Agrinion, Samsun, Basma, Kabakulak, Burley, Virginia and Havana, belonging to Nicotianatabacum, and Brasilia belonging to N. rustica) were grown in pots in the greenhouse where lead acetate had been added to the soil at the rates of 0, 0.1, 1.0 and 10.0 g Pb/kg soil. In the field, 20 g Pb/m² in two forms (nitrate and acetate) were applied to Burley and Kabakulak types. The greenhouse experiment showed that only the highest rate of lead addition to the soil reduced the leaf yield significantly. The higher yielding types (Havana and Samsun) were found to be the least tolerant, while Brasilia was the most tolerant. At all levels of lead addition to the soil the lead concentration in leaf was found to be highest in the first of the three harvests which were made. The relationship between log (lead level in the soil) and log (leaf lead concentration) seemed exponential. Although control treatments in the field and the greenhouse experiment showed comparable leaf lead concentrations, leaf lead concentrations at 20 g Pb/m² in the field experiment were found to be higher than those at 1.0 g/kg soil in the greenhouse experiment.