A hero of the October revolution of 1973 that brought about an end to one-man authoritarian rule, Prapat Panyachartraksa is now a successful organic farmer in Lampang.

Last year, his 200-rai tangerine orchard won an award from the Department of Agriculture Extension for success in reducing chemical residue to an harmless level by adopting the Integrated Pest Management and organic farming system. Before embarking on his ambition to be a farmer, Mr Prapat worked in a reafforestation project at Ban Mae Suk forest in Chaehom district for five years. After saving up enough to buy 80 rai, the Kasetsart University graduate started to put his knowledge into practice.

He started with cash crops such as pineapple, sugar cane and groundnut. but lost all the money because of high labour costs. But he did not give in. He moved on to several jobs to save money and pursue his desire to become a successful farmer.

Married in 1981 to an economics graduate from Thammasat University, Mr Prapat and his wife Kanya worked with his brother for 10 years. They agreed that they would go back to farming once enough money had been saved.

And they made it. Mr Prapat said they saved more than 10 million baht and decided to embark on a tangerine orchard in Lampang. They also thought of other plantations such as sweet tamarine, lychee and longan, but gave up the idea due to price fluctuations.

In fact, the decision had been made in his childhood. Mr Prapat's friend Phakorn Nitcharoenkul showed him his mandarin orchard in Yala. Fascinated, he started to study the trees and visited several plantations.

The final decision was made when former Agriculture Minister Phanlert Buranasillapin and the owner of the famous citrus orchard in Chiang Mai told him the tangerine he intended to farm would not have any marketing problems and had great export potential.

This tangerine is normally called mandarin or Citrus recticulata and originally came from China. It was first grown in Yala.

In 1990 Mr Prapat started clearing his land to plant 1,300 seedlings and the crop yielded after three and a half years. But all did not go smoothly.

"It's just like a chemical war with insects and the diseases. We had to spray the trees with insecticide every 7-10 days," he said.

For the first two years, he said each month he spent a fortune on a cocktail of chemicals, but to no avail.

He said farmers have been greatly encouraged to use pesticide, for example a free trip to America and elsewhere is offered to a farmer who purchases more than 500,000 baht of pesticide.

Mr Prapat decided to cut down on the use of chemicals after he found its residue killed his livestock and pets.

"The residue would last for months. Workers refused to spray the chemical for fear of ill-health. We started to worry about our consumers and the high expense of pesticide," he said.

That was when they turned to the Integrated Pest Management and organic farming system.

He said he used insect traps and biological pesticide such as neem tree's seed extracted for its effective solution against insects.

He applied antagonistic fungus of Genus Trichoderma and Chaetomium against the soil-borne fungus as recommended by Dr Kasem Soythong. His orchard is open for observation and academic study.

Chemicals are selectively used in the orchard to ensure minimum residue and effects on consumers and the environment. Studies of each group of chemicals and matter toxic to humans and animals have also been conducted.

Since then, chemical use has been reduced to less than 50 percent.

However, in the first year of IPM application in 1994, Mr Prapat saw his produce drop by more than 80 percent. The uncontrollable red mite and rust mite which left spots on the fruit was also a cause of worry.

Mr Prapat sought help from an expert, Dr Angsumal Chantrapat, and was told that he could use predator and parasite insects to get rid of mites and the leaf-eating caterpillars, the insects caused most damage to the citrus.

Mr Prapat said he was studying the life-cycle of all natural enemies of the citrus pests. But the whole process took time.

Dr Kosol Charoensom, an entomologist, said nature had provided plants and trees with more friends than foes, but the balance of nature had been destroyed by humans.

Finding no better way, Mr Prapat said he still used some mitecide and sulphur dust but they were not harmful to living creatures.

However, last year, chemical applications in his orchard dropped by 80 percent and no harmful pesticide has been used this year.

His other success comes from the project to create a suitable environment for plants and trees. The pH (the degree of acidity or alkalinity, 0 is most acidic, 14 is most alkaline, 7 is acid-base neutral) of the soil has been checked constantly and acidity is adjusted with a mixture of organic matters.

"I would like to completely stop using chemical fertiliser but there is no better method so far. I had tried but the produce was greatly affected," he said.

Last year his produce dropped to only 50 tons due to floods and widespread mites, but this year he expects 300-400 tons, he said.

Mr Prapan said his savings lasted him for six years and now he is in the red, but he hopes his debt will be covered by this year's produce.

"I was lucky late last year when the Department of Agriculture certified my produce as free from chemical residue, even though the fruit does not look as unblemished as that of other orchards," he said.

Government agencies have given him full support on organic farming, particularly the Department of Agriculture, the Department of Agricultural Extension and Kasetsart University. Without them, he said, he could not make the organic farming possible.

His Phetlanna Orchard has been selected by the Department of Agriculture as the pilot project for organic vegetables and fruit and provided with an organic label.

"My ambition is to set up an institute for further study of citrus and to train enthusiastic farmers in proper citrus farming," he said.