Chemical analyses
Nitrogen (N) concentration in the plant tissues was determined by the semi- micro Kjeldahl method after the tissue was oxidized and decomposed using a mixture of sulfuric acid with salt (K2 SO4:CuSO4 = 5:1). Phosphorous (P) concentration was determined by the vanado molybdate yellow method, while potassium (K) and sodium (Na) concentrations were determined by flame photometry, and calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn),