BEIJING, Aug 8 (Reuters) - China will launch a campaign to crack down on the use of highly potent and poisonous pesticides which are banned but still in use, a state newspaper said on Wednesday, as fears persist over the country's food safety.

Five pesticides were banned earlier this year, and the Agriculture Ministry was compiling a blacklist of companies still making them, the official China Daily said.

Three companies were still allowed to make the chemicals, it added, but only "in emergency situations to control pests, and under strict government supervision", it added.

In rural China there was a problem with farmers improperly using chemicals and spraying them on crops just before they were gathered and sold, the report said. "As part of the government's food safety strategy, it will educate farmers how to properly use pesticides," the newspaper added.

China uses twice as much pesticide annually as is actually needed which has exacerbated the country's food safety problems, it said.

Part of the problem lay in the web of agencies that share responsibility for food safety, campaigners have said.

For pesticides, the Ministry of Agriculture monitors field use, the state planner and the Commerce Ministry grant production licences, the Ministry of Health is responsible for setting maximum residue levels, and the State Environmental Protection Administration monitors environmental impacts.

Producers are often small-scale, and retailers are sometimes travelling salesmen, making monitoring nearly impossible.

The government used to encourage farmers to use as many chemicals as possible to boost yields and feed a growing population.

That has changed following a series of food scares -- brought to global attention recently following a wave of tainted Chinese-made product scandals -- and Beijing is now trying to get farmers to be more environmentally aware.

REUTERS