 In the second half of the 18th century, population spurts began in districts along the north-central coast of Java, and in the 19th century population grew rapidly across the island.Factors for the great population growth include the impact of Dutch colonial rule including the imposed end to civil war in Java, the increase in the area under rice cultivation, and the introduction of food plants such as cassava and maize that could sustain populations that could not afford rice.Others attribute the growth to the taxation burdens and increased expansion of employment under the Cultivation System to which couples responded by having more children in the hope of increasing their families' ability to pay tax and buy goods.