milkthistle (silybum marianum l.) is a rangeland medicinal plant growing wild in different locations in iran. in the present research work, the effect of n, p and k in their different proportions of n0p0k0, n100p100k50, n150p150k100 and n200p200k150 kgha-1 as compared with control (no fertilizer application) on the plant's growth was put to test. suc variables as plant height, no. of capit...