At the time of Independence, about 75 percent of the India's population was dependent on agriculture. Productivity in the agricultural sector was very low because of the use of old technology and the absence of required infrastructure for the vast majority of farmers. The stagnation in agriculture during the colonial rule was permanently broken by Green Revolution. This refers to the large increase in production of food grains resulting from the use of high yielding variety (HYV) of seeds especially for wheat and rice. The first phase of green revolution (approx. mid 1960s up to mid 1970) was restricted to the more affluent states such as Punjab, Andhra Pradesh and Tamil Nadu. The spread of green revolution technology enabled India to achieve self sufficiency in food grains.