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United States Department of Agriculture

Agricultural Research Service

Biocontrol FAQs for Kids

Finding and Testing Biocontrol Agents

One good place to start looking for BCAs is in a field where there are some healthy and some sick plants.

Maybe there is a "biocontrol agent" around the healthy plant protecting it. The scientist looks in some of the soil around the heathy plant roots for microorganisms that can be tested to see if they might be a "biocontrol agent" (BCA). Click here to see microbes grown from soil.

After the microorganisms are grown and isolated, they are tested in the laboratory (where the scientist works) to see if they might be a biocontrol agent.

One test is to see if the BCA makes a compound (like the antibiotic you take for a sore throat) that can kill the pathogen (or slow it down). To do this, the scientist grows the pathogen at one end of a petri dish and the BCA at the other. They grow towards each other. If the BCA does make such a compound, the pathogen stops growing. Want to see?

Another test is to mix the biocontrol agent into some pots of soil with the pathogen. Some pots only have the pathogen (the disease control) and some do not have either the BCA or the pathogen (the healthy control).

Seeds are planted into these pots. This is called an experiment. If the seeds don't grow or grow and then die in the pots with the pathogen only, but grow fine in the pots with the pathogen and the BCA, and the pots with just soil, the scientist thinks he may have a BCA and should do more tests!

Perhaps the BCA protected the plant in some way from the actions of the pathogen, thinks the scientist, who now gets . .

Cartoon, animated mouse-scientist, jumping up and down with glee Pink arrow pointing at animated mouse     EXCITED!!!

 

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Last Modified: 12/17/2009