Planetary dispositors play an important role in Astrology. The dispositor is a planet in whose sign another planet is located in the natal chart and which resident planet gains strength when its dispositor is also strong.
The dispositor is the planet which is the ruler of the sign or house that is occupied by any another sign or house lord.Western astrology looks upon planetary dispositors as the final response to the meaning of an aspect in a horoscope, and it prefers drawing up of Dispositor trees that assist in determining in the Natal Chart the temporal status and the active nature of all planets.
The concept of Planetary dispositors is not new to Hindu astrology, the ancient Hindu texts on Hindu predictive astrology have described numerous yogas based on this principle. In fact, most yogas are dependent upon the benefic placement of the dispositors of the planets giving rise to those yogas. In Hindu astrology the Planetary dispositor is also known as the Poshaka, meaning the "Nourisher", because it tends to aid the occupant of its sign or house.
Whether the planet occupying a particular sign and bhava will act as a benefic or a malefic also depends upon its dispositor acting as a benefic or a malefic. If the sign and the navamsa of the dispositor are both strong then they add to the strength of the resident planet. The result of the aspect of the dispositor on its own occupied sign or house or on any other planet depends upon its own basic nature, and its acquired strength and qualities. Dispositors tend to give results of planets which are occupying their signs, they carry the tendencies of those planets. The Sun. Saturn, Rahu and the lord of 12th house possess separatist tendencies (in respect of marriage, partnership etc.;), their dispositor will also carry the same separatist tendencies where ever it be situated, the role of dispositors in conjunctions and aspects is important and cannot be ignored.
The status acquired by dispositors of Sahams, the sensitive points, in the Varshaphala charts is equally important . The Saham that is aspected by its dispositor or a benefic prospers or if the dispositor aspects the lagna, but not so when the aspecting planet is itself weak in strength or occupies the 6th, the 8th, or the 12th house.
The signs the planets happen to occupy are vital for determining friendship between planets and their dispositors.
When no planet occupies its own sign then all planets so placed create a continuous flow of energy from one to the other. In the formation of Dhvaja yoga each of the seven planets (Rahu and Ketu excluded) strong and alone are in another’s sign, with one of them situated in the Lagna.