WASHINGTON (AP) _ Refusing to be bested by ''Star Wars'' researchers, Agriculture Department scientists have developed their own high-tech weapon.

It won't blast missiles out of the sky.

It will blast water out of mushrooms.

It's called the ''mushroom cannon,'' and scientists at the department's Eastern Research Center in Philadelphia are declaring it a boon for both growers and packagers of mushrooms.

Michael Kozempel, a chemical engineer at the center, said he sees the ''puff-dried'' mushrooms that the cannon produces being used as ''something like croutons people sprinkle on salads.''

Or, if you buy them puff-dried and then change your mind, you can always rehydrate them by dropping them in boiling water.

In fact, explosion-puffed mushrooms are better at soaking up water quickly than air-dried mushrooms because puff-drying creates a porous texture that brings on quicker absorption, the department said.

It works like this:

The 10-foot barrel of the puffing cannon is fed by a conveyer belt that loads in mushrooms that already have been partially dried.

Once the mushrooms are inside the puffing gun, steam pressure surrounding them is raised to 28 pounds per square inch.

After 40 seconds of that treatment, pressure is released instantly, ''causing the moisture literally to explode inside them, shooting them out of the puffing gun into the air, where they become finished, dried product,'' Kozempel said.

Scientists said puff-drying saves more of the mushroom's flavor and nutritional value, especially B vitamins.

They said puff-drying could save money for packagers over conventional drying systems as well as for growers. In the latter case, it could afford them greater flexibility as to when they sell their crop.

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WASHINGTON (AP) - Construction is under way on a 164-foot high experimental windmill designed to produce 500,000 watts of electricity in a 28 mph wind.

The vertical axis wind turbine is being constructed at the Agriculture Department's Bushland, Texas, wind power research facility.

A substantial amount of testing of the shaft will have to take place before the turbine's blades are installed next spring, according to Nolan Clark, a USDA Agricultural Research Service engineer.

Clark will monitor the turbine's performance in the wind power experiment being conducted jointly with the Energy Department.

''We're especially concerned about whether the turbine will provide steady voltage,'' Clark said.

Voltage fluctuations could disrupt automated feeding, milking and irrigation systems on ranches, he said.

''Our tests will provide the kind of data farmers and ranchers and entire communities need in deciding whether or not this type of turbine is right for them,'' he said. ''Private businesses have also expressed a lot of interest in what we're doing here.''

Plans call for two slender aluminum blades attached to a rotating shaft.

''It's the same principle behind electric power plants using coal, oil and even nuclear fuels,'' Clark said. ''In this case, the energy to turn the magnets comes from the wind.

The turbine was designed at Sandia National Laboratories in Albuquerque, N.M., the principal Energy Department facility for developing such technology.