Scientists discover pesticide in cloves

By Joko Sarwono

BOGOR (JP): After nine years of study, experts from the Research Institute for Spice and Medicinal Crops (Balittro) in Bogor, West Java, discovered a chemical compound that can kill nine types of fungi that cause diseases in plants.

The compound, a phytopesticides which the researchers call eugenol, is obtained from clove.

Mesak Tombe, who headed the team of researchers at Balittro, says the compound is able to kill eight pathogen fungi he identified as: Fusarium oxysporum f.sp. vanillae, F. oxysporum, F. solani, Sclerotium rolfsii, Phytium sp., Phytophthora capsici, Rizoctonia solani and Rigidoporus lignosis. The fungi are said to affect vanilla, cashew and pepper.

The phytopesticide is safe for humans and animals. "Our laboratory testing showed that eugenol did not have any side effect on worms, fish or chickens," Mesak says.

Balittro places a high priority on researching phytopesticides, which are environmentally friendly. The discovery is expected to cause a jump in the price of clove, which plummeted in the 1990s, when the phytopesticide is produced on a mass scale.

Mesak says the mass production of eugenol would allow clove farmers to sell their products to the pesticide industry. Currently, most of the clove goes to cigarette factories.

"In the future, farmers will have a stronger bargaining position and this will encourage farmers to plant clove," Mesak says.

Eugenol is found in all parts of the clove plant, although it is most strongly concentrated in the flowers. Even the dried leaves of clove contain the compound.

"If the farmers prefer to sell the flowers to other industries, the pesticide factories still can buy the dried leaves; so it will never run out of raw materials," Mesak said.

The discovery is also expected to encourage local industrialists to get into the phytopesticide business, which in turn will help reduce Indonesia's dependence on imported pesticides.

According to Mesak, Indonesia imported about US$200 million worth of pesticides each year.

"If the home industry can supply just 30 percent of the pesticides, we would be able to save a lot of money," he says, adding that there was a factory that expressed interest in producing eugenol.

Imported pesticides costs at least Rp 100,000 per liter, which is too expensive for most Indonesians. While locally produced pesticides cost only Rp 30,000 per liter.

Mesak plans to commercialize the discovery next year and he has registered with the government for a patent.

Eugenol has been produced on a limited basis and has been used by vanilla and cashew nut farmers in Bali and Sukabumi and by pepper farmers on Bangka island.

A.A. Sofyan, the chairman of a 118-strong vanilla farmers group in Sukabumi, is one of those who has used the phytopesticide.

He said he was satisfied with the results. Just a week after he sprayed eugenol, the diseases were gone and his vanilla grew better.

"Now my vanilla grows very well and the harvest is coming soon," he said when attending a recent seminar in Bogor on the discovery.

Sofyan, who has grown vanilla since 1982 in Sukabumi, said the pest worst affected his vanilla farm in 1997, when an estimated 50 percent of his plants had the lethal fungus.

He tried the locally made eugenol in early 1999 on Mesak's recommendation.

Soelaksono Sastrodihardjo, an expert on phytopesticides, said he hoped the use of eugenol would help reduce the negative effects of imported pesticides on the environment.

According to Soelaksono, some 200 types of pesticides are currently on the Indonesian market and farmers spray about 18,000 tons of them every year.

He said the uncontrolled use of pesticides was responsible for pests' increasing resistance to the pesticides.

"The pesticides can poison the farmers, pets and animals useful to human beings," he added.