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This is Steve Ember with the VOA Special English Agriculture Report.

A discovery about a chemical in smoke could be a big help to farmers. Smoke causes lots of seeds to begin to grow. But smoke contains lots of different substances. No one knew which one caused the process of germination to begin.

Now researchers from the University of Western Australia say they know. They published their findings this month in the magazine Science. The compound is called butenolide.

To find it, the Australian team burned plants as well as paper. Both contain cellulose, the basic material of all plant life. The team separated butenolide from the other substances in the smoke from the burnt cellulose. Their work took eleven years.

They performed experiments on seeds that normally germinate after fires. They also included seeds from plants that do not normally need fire to germinate. They found that both kinds of seeds germinated at a high rate when treated with butenolide. They found that even an extremely small amount of this carbon-based chemical can be effective.

The discovery of butenolide could mean a lot not just to farmers but also to scientists who want to help rare plants grow. It could be used on wild lands and to help forests grow back more quickly after fires.

Farmers could treat seeds with butenolide to increase the productivity of their crops. Kingsley Dixon, a member of the Australian team, notes that it could also be used to control unwanted plants. A farmer could treat fields with the chemical. This would cause weeds to germinate and grow. Then the farmer would use other treatments to kill the weeds before any crops are planted.

Most kinds of seeds require a period of inactivity before they can germinate and send out roots. Inactivity is a natural defense, so the plants do not attempt to grow when conditions are poor. Some seeds need cold weather before they can germinate. Others cannot sprout until their outer skin is broken, which heat from a fire can do.

Smoke from forest fires is known to cause seeds to germinate immediately. Now, scientists know what it is in smoke that causes seeds to start to grow. What they do not know yet is why butenolide does what it does.

If you have a question about agriculture, we might be able to answer it on the air. Send an e-mail to special@voanews.com. And put the word agriculture in the subject line.

This VOA Special English Agriculture Report was written by Mario Ritter. This is Steve Ember.