For the second week in a row, the New England Repertory Players have chosen a potentially entertaining vehicle and then failed to give it the performance it deserves. Paul Osborn's "The Vinegar Tree" has all the characteristics of delightful farce: sparkling dialogue, timely action, and an appealing story. Except for an unnecessarily tricky final curtain, the play itself can easily be cast and directed to complete success.

But numerous small faults mar the efforts of a hard-working cast. Poor lighting arrangements leave a third of the stage dark, costumes clash violently with upholstery, and a supposedly "meditative" character walks on stage with the "Reader's Digest" in one hand. Such incongruities detract continually from a comedy which otherwise would carry its audience along without pause.

Any amateur cast would find its talents inhibited by repeated mechanical difficulties, and a heavy load falls upon the Playhouse's experienced wheelhorses. Burt French, Katherine Whitfield, Carol Wheeler, and John Rand '43 support the double triangle around which the plot moves. Adele Thane as a scatterbrain middle-aged wife is glaringly miscast; she parboils the comic two thirds of her part and convincingly portrays a dramatic third act. Make-up difficulties hamper Robert Bastille'43, for his audience cannot forget that they see a Harvard man disguised as a sexagenarian.

"Vinegar Tree" has turned out sour on its opening night. The shortcomings, however, are easily correctable with little effort. Shifting a spotlight six inches to one side, a rearrangement of properties and one or two simple cast shakeups can save a clever comedy. With those few alterations, Joy Street's second presentation of the year will be well worth attending.