Disclosed are methods for modulating root initiation and extension in a plant comprising: (a) treating a root of a plant with a composition comprising an anthraquinone derivative such as chrysophanol in an amount effective to modulate root extension when transplanted into soil and (b) transplanting the treated plant of (a) into soil. Also disclosed is a method for promoting germination of a seed of a plant comprising applying to said seed an amount of a composition comprising physcion effective to promote said germination of said seed of said plant and optionally a seed coating agent. Chrysophanol is also known as 1,8-Dihydroxy-3-methylanthraquinone, and 3-Methylchrysazin. Further disclosed is a composition for modulating germination comprising one or more anthraquinone derivatives.
