Maryland Gov. Harry Hughes announced yesterday that he has asked the U.S. Department of Agriculture to declare 21 counties, including Prince George's and Montgomery, federal disaster areas because of the severe drought that has parched farm land throughout the Southeast this summer.

While the request raised hopes of at least some financial assistance in the form of loans for Maryland farmers who have seen their crops wither this year, residents of Arlington received more direct help yesterday. The Arlington County Board eased restrictions imposed 11 days ago after a major water line burst at the same time that the county faced record water consumption.

Under the old restrictions, residents were told they could not water their gardens or lawns or wash their cars, unless they used less than three gallons of water in a bucket. Now those residents with odd-numbered street addresses may water on odd-numbered dates, and those with even-numbered addresses on even-numbered dates. Residents are still barred from washing vehicles, except with a three-gallon bucket limitation.

Although it will take several weeks before the water main, which runs under the Potomac River, is repaired, county officials said that a 50-year-old back-up system has allowed them to provide almost the usual amount of water to county residents.

In the Washington area, rainfall at National Airport has been measured at 3.26 inches so far this month -- which is 0.62 of an inch above normal. But even so, U.S. Weather Service forecaster David Caldwell said, the rainfall for the year is 13.89 inches, about 7.25 inches below normal.

Caldwell said scattered afternoon thunderstorms may bring more rain today and tomorrow. He said the chances of a more steady rain that would present a better source of relief for farmers look stronger for Saturday and Sunday, when a mild low pressure system is expected to move through the area.

George Lechlider, who grows corn and raises livestock near Laytonsville, said recent rains have helped but farmers need a regular rain of at least two inches a week to salvage what is left of their crops. "If it would rain from here on out, we could get maybe 30 or 40 percent of our crop of corn," he said.

If Hughes' request is approved by federal officials, farmers would be eligible for low-interest loans designed to help them overcome drought losses estimated at $89 million statewide. They could also seek subsidized feed grain for their livestock.

Last week, Virginia Gov. Gerald L. Baliles said he is asking that 17 southeast Virginia counties be named disaster areas. He said farmers in those counties anticipated losses of about $61.5 million. About 20 other counties have also asked Baliles to seek the designation. Disaster assistance has already been sought for Alabama, North Carolina, South Carolina and Delaware, while Georgia Gov. Joe Frank Harris has said he will be asking for aid soon.

Jeanne Kling, a spokeswoman for the Farmers Home Administration that administers the emergency loans sought by Hughes, said it often takes several weeks or months for the U.S. Department of Agriculture to declare an agricultural disaster because it can take a long time for the effects of a drought to be calculated. Once a disaster is declared, she said, a farmer living in the area has up to eight months to apply for a loan.

In Maryland, only mountainous Allegany and Garrett counties have escaped the effects of the drought, which has given state farmers an average of just over half their normal rainfall for the year. Although thunderstorms in the past few days have dumped heavy rains in some areas, they have fallen far short of the nine to 12 inches of rain farmers say they will need to give their crops a chance of survival.

Recent rains have not been enough to end water restrictions in Anne Arundel County, where outdoor water use has been curbed since early June.

Despite a severe thunderstorm that brought 2.5 inches of rain to the Annapolis area Sunday night, Anne Arundel officials said restrictions prohibiting outdoor water use between 4 and 10 p.m. on weekdays, and from noon to midnight on weekends probably will remain in effect until the drought is clearly over.

In Fairfax and Prince William counties, watering is allowed Saturdays for odd-numbered addresses and Sundays for even-numbered addresses under voluntary restrictions.

Officials in other area jurisdictions said they have not imposed any limits on water use, but are monitoring their water supplies daily as the area yesterday entered its 24th day of temperatures exceeding 90 degrees since June 1.

Even with a steady rainfall, Maryland agriculture officials said many farmers have reported it is too late to save much of their corn -- the state's largest crop -- and hay. Most of the state's corn and soybeans are used to feed chickens, which are Maryland's most valuable farm product, while hay is used to feed livestock in winter. Because pastures have dried up, however, many farmers are already feeding their cattle whatever hay they have been able to harvest.

The federal officials have already decided that the drought "is every bit as serious as portrayed by the governors," said Jim Spitz, a federal agricultural department spokesman. "It's a serious situation, running all the way from the northern tier of Florida clear up to Virginia and Maryland and Delaware."

If U.S. Agriculture Secretary Richard Lyng declares a disaster, a Farmers Home Administration spokesman said, loan restrictions introduced this year could make it harder for farmers already in financial difficulty to obtain disaster loans. Nonetheless, Doug Tregoning, an agricultural agent in Montgomery County, said that the loans and feed grain assistance "could be useful to some farmers. But I don't think anybody's sure what the programs are going to entail at this point. Certainly I think there's going to be farmers looking for feed this winter, because pasture, hay and corn silage are going to be in short supply. They are right now."

Tregoning said drought losses in Montgomery have been calculated at $6.3 million so far, which assumes the loss of about one-third of the county's crops. Losses by livestock farmers, who account for about half of the county's $30 million a year farming income, will be felt later and have not yet been counted, he said.

Lechlider, the Laytonsville farmer, said he is happy Hughes is seeking disaster assistance and is sure many farmers will benefit from any low-interest loans. But he noted that loans will not be able to help many of the farmers in the worst distress.

"Low-interest loans are fine, but the man still has to pay his money back," he said. " . . . If you can't pay it back, it's just putting you that much deeper in the hole."