General Castro said a coca farmer could harvest leaves from a bush "three, maybe four times a year."

Morales's support from coca farmers was seen as a large reason for his victory to the open presidential office in the 2005 election.

But in conversations with more than 20 coca farmers recently, only one spoke well of Umopar.

There is a strong case for trying to persuade Bolivian coca farmers to grow something else.

He added: "If you're saying that coca farmers won't be able to make a living after we spray, that's right.

What are coca farmers and processors to do for a living if they don't grow coca?

Government officials said the savings will go into law enforcement and economic development, but they concede that the policy is unpopular among coca farmers.

Now you are going to have coca farmers with land titles.

The southern portion of the park has been colonized by agricultural settlers, primarily coca farmers, since the 1970s.

All across the country, coca farmers use similar methods.