Commercialisation means to make profit from an organisation or activity. In this case, to make money from agriculture. Colonial rule exists when one territory of people is under the sovereignty of another. Meaning that the colony has a metropole (mother city) with a sovereign but that the colonists are still in control of their own government, social structure, and economics. Thus, the phrase, "commercialisation of agriculture under colonial rule" means profit-making from agriculture in a society whose sovereignty is claimed by a metropole.