By Charles Haviland BBC correspondent in southern India

The row over access to the waters of a disputed river is creating growing bitterness and animosity between two drought-hit southern Indian states.

There are plenty of farmers prepared to give their life for the cause of the Cauvery

Karnataka farmer

Visiting rural parts of Karnataka, where the Cauvery River rises, and Tamil Nadu, into which it flows, I heard ominous warnings about this water dispute's possible consequences.

In Karnataka, the public anger is highly visible.

Demonstrations by farmers and local youths have swept through the southern district of Mandya - the heart of the state's farmland irrigated by the Cauvery.

Towards dusk one afternoon, they set burning tyres across the road to stop people passing.

A little further on, our car was daubed with slogans against Tamil Nadu and its Chief Minister J Jayalalitha.

Judiciary faces ire

Rage is being vented against the Indian Supreme Court over its rulings that Karnataka should release more water from its dams.

"To hell with the Supreme Court!" chanted farmers at another protest. "The Cauvery is ours!"

In the village of Shrirangapattana, farmers leading their bullock carts paraded a huge effigy of Jayalalitha through the streets, flaying it with branches.

The Cauvery dispute is more than 100 years old.

It surfaces whenever there is drought, but this year things have been especially bad.

Harvests threatened

The main crop at stake is southern India's staple, rice, which needs large inputs of water.

The dispute has become highly politicised

"There are hundreds of thousands of acres drying up for want of water," G Shivakumar of the local farmers' agitation committee told me.

His talk was of sacrifice.

"There are plenty of farmers prepared to give their life for the cause of the Cauvery," he said.

One farmer has already died after jumping into one of the state's main reservoirs, Kabini.

Drinking water supply has also been hit by the drought.

M Lingaiah of the Farmers' Welfare Association said cities including the state capital, Bangalore, were running short.

Withering crops

The countryside around Mandya looks quite green.

The river is a popular with swimmers

In some fields, we saw healthy-looking rice and sugar crops.

But farm labourers planting a coarse grain, ragi, told me the irrigation water was being strictly rationed.

"We're getting half the normal amount of water," one told me. "How can we spare any?"

But, far downstream in Tamil Nadu, things are just as bad.

Banana trees dependent on irrigation are visibly withering in plantations near the town of Tiruchchirappalli.

Between here and the sea lies the Cauvery Delta, a vast and usually fertile rice-growing plain.

Some of this country looks its usual lush colour.

Large tracts, though, simply have not been planted this year and are brown and cracked, with just the odd green, irrigated field.

Cattle sold off

Ramayan, who is over 70, and his wife Panjali are tenant peasant farmers in Thanjavur district.

Some tenant farmers have suffered big losses

They usually farm three fields with paddy, but this year they have only been able to plant one - with a vegetable, bitter gourd, "just for pocket money", says Ramayan.

Ramayan and Panjali will have to borrow to buy rice which they would normally grow for themselves.

Usually this area would be harvesting a short-term rice crop around now.

But only a third of the crop has been grown this year.

A longer-term rice crop, due for transplanting about now, has mostly been lost.

S Ranganathan, who is secretary of, the Cauvery Delta Farmers' Welfare Association, has grown nothing this year.

He points out that thousands of cattle have been sold off to tanneries in anticipation of their imminent death.

Their usual fodder is the straw that is left when the rice is harvested.

'Politics at play'

It is not all gloom.

At the Grand Anicut water regulator - an ancient structure at the point where the Cauvery splits into a delta - families and groups of friends come to relax, picnic and go swimming.

Many farmers have grown no crops this year

At this peaceful spot I met many people ready to see the opposing viewpoint.

"We know that farmers are suffering not only in Tamil Nadu but also in Karnataka," a local teacher said.

But this dispute has become highly politicised.

The Karnataka Chief Minister, S M Krishna, has this week been staging a long march of solidarity with the state's farmers.

His confrontational Tamil Nadu counterpart, Ms Jayalalitha, is taking him to court in a contempt action because of Karnataka's failure to obey injunctions on the release of water.

Both state capitals have staged one-day general strikes, and widely adored figures in the two states' glamorous film industries have entered the fray with their own demonstrations.

In both states there is a feeling that all this is unhealthy.

"The issue must be depoliticised," says a former judge and expert on the Cauvery issue in Bangalore, Balakrishna.

"It needs the human treatment."

But the recriminations flow.

Difficult times

Karnataka accuses Tamil Nadu of wasting water and greedily expanding its irrigated land.

Farming depends on irrigation from the Cauvery

Tamil Nadu retorts that its neighbour has forgotten the principles of sharing, or should be concentrating on crops other than rice.

The current crisis may be headed off, especially if recent light rains in the river basin get more intense.

A return to the type of water-related violence seen in 1991, when 25 died in clashes in Bangalore, seems unlikely.

But people are sounding a note of warning.

The Supreme Court's next ruling on the dispute is due on 24 October, and M Lingaiah says that if it goes against Karnataka, "a war-like situation will arise."

On the other side of the border, S Ranganathan hopes Tamil Nadu will not see the kind of protests staged in Karnataka.

"If that happens," he says, "God only save us."