PHILADELPHIA (AP) _ United Farm Workers President Cesar Chavez and 100 supporters rallied outside the annual A&P stockholder meeting Thursday to urge the grocery chain to stop selling California grapes treated with pesticides.

''The message I want to give them is, 'You have a moral responsibility with the growers to stop poisoning the consumer','' said Chavez, who complained the pesticides can cause cancers and birth defects.

Chavez had hoped to force the stockholders to consider the UFW's request that A&P pull all California-grown grapes from its shelves, but the meeting at a Philadelphia hotel ended before the protesters arrived.

''We are trying to get them to recognize that the grapes they sell are contaminated,'' he said. ''We're trying to get them to recognize that the contaminated grapes are hurting consumers.''

Before the shareholders meeting adjourned, James Wood, chairman and chief executive officer of The Great Atlantic and Pacific Tea Co., warned shareholders the protesters would be outside.

''By all means listen to what they say if you want, but realize that they (the grapes) are safe to eat,'' Wood said, later adding ''he's (Chavez) got a political union problem.''

The California Grape Workers and Farms Coalition has countered the UFW's charges, saying they were raised in response to appointments to the California Agricultural Labor Relations Board opposed by the union.

''We are opposed to the charges,'' said Adam Ortega, a spokesman for the coalition. ''It's a bunch of baloney. The grapes are not in any way tainted.'' The UFW in 1986 called for a nationwide boycott of A&P after the supermarket chain refused to pull California grapes from it shelves.

During the shareholder's meeting, Wood released the company's financial report for its first fiscal quarter.

A&P earned $30.37 million or 80 cents per share, a 60 percent increase over the year-earlier period's earnings of $28.69 million or 76 cents a share. The company had fewer shares outstanding last year.

First-quarter sales totaled $2.9 billion vs. $2.1 billion.

A&P operates 1,194 supermarkets in 25 states and Canada under the A&P, Super Fresh, Food Emporium, Kohl's, Family Mart, Dominion and Waldbaum tradenames. It is the fourth largest major food chain in the country.