India's monsoon was about 20 percent below strength just over a week before the official end of the rainy reason, putting the country on course for its worst drought since 1972, weather data showed Wednesday.

"Until September 21, for the country as a whole, the rain deficiency was 22 percent," said B.K. Bandopadhyay, a spokesman for the weather office.

"We expect the total rain deficiency will be roughly about 20 percent (at the end of the monsoon season). It depends on the rainfall, but it seems it will be around this number," he added.

Low rainfall early in the monsoon period ravaged India's rice, cane sugar and groundnut crops, and has disrupted the flow of water into the main reservoirs that are vital for hydropower generation and winter irrigation.

The drought is expected to dampen India's economic growth this year and has sent food prices rocketing, leading to huge hardship for India's poor masses.

Chicken prices, for instance, rose 16 percent in the week to September 5 and fruit and vegetables climbed eight percent from the previous week, official data shows.

In August, Prime Minister Manmohan Singh admitted that the country faced a "severe drought" but he said that ample food grain stock would ensure no one went hungry.

Bandopadhyay said that a rain deficit of 20 percent would be worse than previous droughts in 2002, 1987 and 1979 when the shortfall was about 19 percent.

In 1972, the deficit measured 23.9 percent, he said.

The monsoon period in India runs from June to the end of September, though late rains have been experienced in October.

India's weather service said recent reports showed that more than half the country was affected by the drought and the key farming areas in the north, northeast and some parts of western India were worst affected.

Rains in the northwest were 34 percent less than average, in central regions they were down by 19 percent, and the northeast had a 26-percent shortfall.

Experts said the farming population faced tremendous pressure due to the severe water shortage this year. Much of India's farmland lacks irrigation, meaning farmers are dependent on the monsoon rains.

"This is a crisis for sure," Devender Sharma, a food policy analyst based in New Delhi, told AFP.

Sharma said India had 50 million tonnes of wheat and rice as buffer stock, ample to ensure steady food supplies.

"Food will have to supplied to the worst affected areas efficiently to prevent wastage," said Ravi Jalan, an agriculture scientist.

Jalan said India wasted more than 50 billion dollars of food grains every year, mainly due to the lack of post-harvest infrastructure such as appropriate storage facilities and transportation.

Officials at the weather service said they would collect all the rain distribution data at the end of the monsoon season to assess the drought situation.