Effects of Fertilization on Growth and Productivity of Three Milk Thistle Populations

Milk thistle is an important medicinal plant as it contains silymarin which has many pharmaceutical activities. The purpose of this study was to evaluate the influence of a stabilized nitrogen fertilizer alone or combined with a foliar fertilizer, containing phosphorous, potassium, iron, manganese, and zinc, on the plant development and fruit yield of three wild milk thistle populations originated from Greece. The fruits of the populations ‘Palaionterveno’, ‘Mesopotamia’, and ‘Spata’ were sown in plastic pots containing peat. Fertilization treatments were i) control - without application of fertilizer, ii) application of a stabilized nitrogen fertilizer, and iii) use of the stabilized fertilizer followed by applications of foliar fertilizer at three different growth stages. The results revealed that genetic material significantly affected the plant height, rosette diameter, and dry weight of root system. Moreover, the application of the nitrogen fertilizer alone or combined with a foliar fertilizer enhanced plant growth. Regarding the fruit yield, there was an interaction between the two factors.