DISTRIBUTION PROFILES OF SELECTED MICRONUTRIENTS IN ORIENTAL FIELD-GROWN TOBACCO PLANTS AS AFFECTED BY NITROGEN-FERTILIZATION

In an attempt to investigate nitrogen (N)-fertilization which is consi dered incompatible with oriental tobacco agricultural practice, the in fluence of N-fertilization (no fertilization or ammonium nitrate ferti lizer applied at either 50 or 100 Kg N ha(-1)) the growth stage (plant age) and the stalk position (basal, middle, and upper) on the micro-n utrient concentration distribution in leaves of the oriental tobacco c v. Myrodata Agriniou was studied. All investigated factors affected, I ) the leaf micro-nutrients concentrations and leaf dry matter of field grown tobacco plants in the following order of decreasing strength: N -fertilization level > growth stage > leaf position and ii) the stem m icronutrients concentrations and dry matter accumulation in the order: stalk position > growth stage > N-fertilization level. Both N-fertili zation level and growth stage were positively correlated with dry matt er accumulation, but negatively with zinc (Zn) and copper (Cu) accumul ation. In addition, N-fertilization was negatively correlated with man ganese (Mn) concentration, while the same was true for the correlation of growth stage with iron (Fe). With the exception of Mn, leaf positi on was negatively correlated with every parameter investigated. Stem m icro-nutrient concentration were lower than those of the leaves. Manga nese showed the higher differences in concentration level between leav es and stems. It is concluded that N-fertilization delays leaf maturin g and senescence, increases leaf size, as well as the leaf fresh weigh t and the micro-nutrients accumulation especially in the basal leaves.