LEXINGTON, Ky. (AP) _ Adverse weather conditions during the tobacco growing or curing season may have ruined 25 percent or more of the unsold 1997 crop.

``We would need at least two weeks of summer weather to help growers salvage what they can, and that's not going to happen,'' Gary Palmer, a tobacco specialist at the University of Kentucky College of Agriculture, said Wednesday.

The past year was a ``bad one from start to finish for the tobacco grower. Some told me they've never seen anything like it,'' said Palmer, who was attending a meeting of directors of the Burley Tobacco Growers Cooperative Association in Lexington, Ky.

Tom Norvell, senior vice president of Universal Leaf North America, reported findings from a survey of tobacco warehouses.

``If there is a market for this tobacco, we don't know where it is,'' Norvell said.

Throughout the eight-state Burley Belt, an estimated 50 million pounds is ruined, said Norvell, whose company buys and processes burley tobacco. And that estimate could turn out to be conservative, he said.

If 50 million pounds were ruined, growers' income would be reduced by $95 million, or nearly 10 percent of the entire harvest. Some of the worst losses are expected in central Kentucky.

``We've heard reports of some growers losing their entire crop,'' Norvell said.

Tobacco fell victim to a peculiar growing season that included either too much rain or too little rain and a curing season that was too dry, too wet or subfreezing.

``For a lot of farmers this is very close to a disaster,'' said Rob Amburgey, a University of Kentucky agricultural extension agent in Jessamine County.

He predicted that more than 25 percent of the tobacco still in barns will be ungraded or unmarketable. Growers whose tobacco froze last fall will be lucky to salvage two-thirds of their leaves, he said.

``Either the tobacco is frozen, or it's got very high nitrogen (which turns the leaves green), or it's got bleed-back, where juices from the stalk have stained the leaf green,'' Amburgey said.

Palmer said he feared that Norvell's estimate is accurate. That will force growers to keep the tobacco off the market and hope it cures enough to sell next year.

``The grower doesn't have much choice but to keep it over the summer,'' Palmer said. ``But if it's not handled right it will get moldy. If that happens, there's no salvation for that tobacco.''

Norvell held out faint hope that some of the leaf now hanging in barns might improve with additional curing. The Agriculture Department already extended the market indefinitely beyond its scheduled Feb. 26 close to let marginal leaf continue to cure into March.

Some burley with mild freeze damage might eventually improve enough to sell if farmers allow it to cure over the summer, Norvell said.

``But in severe cases of frozen tobacco, I don't know that it will ever have a value,'' he said.