During the British reign in India, there were several factors that led to a slow growth rate of the population. Some of the main reasons are as follows:

1. Famines:

Famines were a regular occurrence during British rule, and they caused a significant decline in the population. The British government's policies of exporting food grains from India and the introduction of cash crops like cotton and indigo led to a shortage of food grains. This, coupled with droughts and other natural calamities, resulted in famines that killed millions of people.

2. Epidemics:

Epidemics like cholera, smallpox, and plague were rampant during the British rule. The British government's inability to provide adequate healthcare and sanitation facilities worsened the situation. The lack of awareness and education about preventive measures also contributed to the spread of these diseases.

3. Infant Mortality:

Infant mortality was high during the British rule due to malnutrition, lack of proper healthcare, and poor sanitation facilities. The high mortality rate led to a decline in the overall population growth rate.

4. Social customs:

Certain social customs like child marriage and the practice of purdah among women led to a slow growth rate of the population. Child marriage led to a high maternal mortality rate, while purdah restricted women's mobility and access to education and healthcare.

5. Migration:

The British government's policies of promoting migration of people from India to other parts of the world also contributed to a slow growth rate of the population.

Conclusion:

In conclusion, the British rule in India had a significant impact on the growth rate of the population. The policies and practices implemented by the British government resulted in famines, epidemics, and high infant mortality rates, leading to a slow growth rate of the population. The social customs prevalent at the time also contributed to the decline in the population growth rate.