AT LAST count there were seven commercial vineyards in Maryland. One that is beginning to raise eyebrows is Byrd Winery of Myersville which was founded in 1972. Byrd produces a range of wines, including Chardonnay, Cabernet and Seyval Blanc as well as the first East Coast plantings of Sauvigon Blanc and Gewurztraminer. The success is at least partly due to Byrd's winemaker Bob Lyons, formerly with Chateau Montelena, whose Chardonnay won the now famous Paris tasting of top French and California Chardonnarys. Byrd wines are offered at a number of local shops, including A&A Liquors, Bell, Eagle, Harry's, Leed, MacArthur and Morris Miller as well as Sheraton-Carlton's wine bar.

It's no secret that higher prices don't always mean higher quality. Recently, however, Alfio Moriconi, head of Wines, Ltd., wine importer and distributor, set out to demonstrate that maxim to about 50 members of Les Cent Chevaliers, a local wine soceity. Moriconi has no objection tok expensive French wines, but rails against expensive poor ones, frequently the result of bottling and selling vintages that he says have no business being sold under a prestigious label.

Moriconi matched nonvintage Bourgogne Blanc, Reserve Le Lion 'dOr (about $6 a bottle) La Cabanne '67, a pomerol ($10-$15) and Bourgogne Rouge, Le Compte de Lupe '78 ($6-$7) against, respectively, Corton Charlemagne, Bichot '77 (about $25), Chateau Petrus '74 (about $60) and Grand Echezeaux Grivelet '73 (about $20). In every case, Moriconi's less expensive choice won the blind tasting. In the case of the Bourgogne Blanc the margin was considerable, about 4 to 1.

The Heublein Wine Auctions have become something of an institution in the United States with its vast assortment of older wines from California and Europe the subject of spirited bidding. Last May was Heublein's 12th Annual Spectacular. Now, London-based Christie's is invading the market with its first American auction, to be held in New York Dec. 9 at Christie's main auction center, 502 Park Ave. Last year Christie's held 44 rare wine auctions around the world with total sales of better than $6 million.

Because of the unusually cold and wet 1980 growing season, French wine harvests are running extraordinarily late. The most immediate impact will be the delay in the opening date for Beaujolais Nouveau, which has been set back to Nov. 20, five days past the traditional date.

Some aficionados of Beaujolais Nouveau (or just plain snobs) charter planes to fly Beaujolais Nouveau from France to the United States so they can be the first in the U.S. to consume it.

Mayflower Liquors is flying 80 cases of Ponzi wines in from Oregon. Ponzi Vineyards, founded in 1970, has 21 awards to its credit from tastings in the Pacific northwest. The wines we'll see are a dry but fruity White Riesling, a dry and slightly chalky Sauvignon Blanc and a White Pinot Noir, slightly pink with good fruit in the taste. They are priced from $4.99 to $5.89 a bottle.