Read the text given below and answer the following questions:
Farming is the main production activity in Palampur. 75 percent of the people who are working are dependent on farming for their livelihood. All land is cultivated in Palampur. No land is left idle. During the rainy season (kharif) farmers grow jowar and bajra. These plants are used as cattle feed. It is followed by cultivation of potatoes between October and December. In the winter season (rabi), fields are sown with wheat. The main reason why farmers are able to grow three different crops in a year in Palampur is due to the well-developed system of irrigation.
To grow more than one crop on a piece of land during the year is known as multiple cropping. One way of increasing production from the same land is by multiple cropping. The other way is to use modern farming methods for higher yield. Yield is measured as crop produced on a given piece of land during a single season. Till the mid1960s, the seeds used in cultivation were traditional ones with relatively low yields. Traditional seeds needed less irrigation. Farmers used cow-dung and other natural manure as fertilizers. All these were readily available with the farmers who did not have to buy them.
The Green Revolution in the late 1960s introduced the Indian farmer to cultivation of wheat and rice using high yielding varieties (HYVs) of seeds. Farmers of Punjab, Haryana and Western Uttar Pradesh were the first to try out the modern farming method in India. In Palampur, the yield of wheat grown from the traditional varieties was 1,300 kg per hectare. With HYV seeds, the yield went up to 3,200 kg per hectare. There was a large increase in the production of wheat. Farmers now had greater amounts of surplus wheat to sell in the markets.
Q. The Green revolution in the late 1960s introduced the Indian farmer to cultivation of: