SINGLE AND MULTIPLE SECONDARY NUTRIENT DEFICIENCY EFFECTS ON FLUECURED TOBACCO

Abstract

With the introduction of high yielding varieties of crops, nutrient removal from the soil is increasing day by day. Though the primary nutrients (N, P and K) are applied liberally to offset their removals from soils, the secondary nutrients (Ca, Mg and S) are seldom used in adequate quantities in crop production to replenish their reserves in soils. This situation often results in occurrence of single and/ or multiple secondary nutrient deficiencies that may affect the nutrition of crops. Against this backdrop, the role of single and multiple secondary nutrient deficiencies were studied on growth, development and nutrient uptake of FCV tobacco in sand culture experiment. Uniform tobacco seedlings of variety Kanchan were planted in pots filled with sand and were supplied with different combinations of nutrients using Hoagland solution. The treatments included six types of secondary nutrient stresses (Ca, Mg, S, Ca + Mg, Ca + S, Mg + S and Ca + Mg + S). At the age of 45 days, observations on morphological, physiological and biochemical characters were recorded. The leaf and stem samples were processed and analyzed for N, P, K, Ca, Mg and S. Results revealed that secondary nutrient stress caused marked adverse effects on the plant in terms of visual deficiency symptoms, reduced plant growth and nutrient uptake. Single and multiple nutrient deficiencies reduced total plant weight, leaf area, and total chlorophyll content. Secondary nutrient stress was associated with the elevated concentration of anti-oxidative enzymes. The reduction in growth and nutrient uptake due to single and multiple stresses are in the order of control <Ca < Mg <S < Ca + S<Ca + Mg < Mg + S <Ca + Mg + S. Secondary nutrient deficiencies influenced the nutrient ratios which affect the quality of leaf. Hence work on secondary nutrients in field conditions will help to understand the role of secondary nutrients on tobacco leaf yield, quality and also facilitates the demand driven fertilizer usage that in turn saves input expenditure to some extent and also protects environment.