Calcium and bicarbonate effects on the growth and nutrient uptake of burley tobacco seedlings: Hydroponic culture¹

Contribution paper no. 98–060154 of the Kentucky Agricultural Experiment Station, published with the approval of the director.

Abstract

In soilless production systems, water quality can have a major impact on the growth of plants. It has become evident that moderately alkaline water is a problem for tobacco transplant growers in some regions of Kentucky. To determine the level of bicarbonate (HCO₃ ⁻) alkalinity, which is detrimental to burley tobacco transplants, and to better understand the effect of calcium (Ca) and the interaction of HCO₃ ⁻ and Ca on the growth of burley tobacco transplants grown in a float system, three levels of CaCl₂ (25,75, and 125 mg L⁻¹ Ca⁺⁺) in factorial combination with five levels of HCO₃ ⁻ (0, 122, 244, 366, and 488 mg HCO₃ ⁻L⁻¹) were tested in nutrient solution culture. Four‐week‐old burley tobacco (Nicotiana tabacum L. var. KY‐907) seedlings were transplanted to 18‐L containers filled with aerated Hoagland's solution with the different levels of calcium and HCO₃ ⁻ for two weeks. High HCC₃ ⁻ alkalinity caused root system damage and plant growth inhibition, but did not induce iron (Fe) chlorosis. A significantly lower concentration of Zinc (Zn) was measured in the shoots as HCO₃ ⁻ levels in solution increased. In the presence of high calcium, plant growth was not significantly improved. No significant interaction of HCO₃ ⁻ and Ca on growth or nutrient uptake was observed in this study.

Notes

Contribution paper no. 98–060154 of the Kentucky Agricultural Experiment Station, published with the approval of the director.