DAVENPORT, Iowa (AP) _ Lisa Ritscher is a farmer's daughter, an old pro with cows and cattle. But she's a novice with cards and craps - two games she has to master for her new career in corn country.

Murray Singbush is a retired businessman, a veteran of the nuts-and-bolts world of farm machines. But he's a stranger to his new surroundings - a glittery floating casino.

This land of farms and factories is changing and many folks are betting that if they play their cards right, they'll be part of a boon that will transform this area into the Monte Carlo of the Mississippi. Riverboat gambling starts here April 1, and many predict it will reap a cash harvest for the heartland.

''Riverboat gambling has that kind of allure that Chevrolet, hot dogs and apple pie has,'' said John Connelly, a Pittsburgh marketing multimillionaire whose boat is among three being launched Monday. ''It will have tremendous appeal in mid America.''

Iowa is the first state to take the plunge. Illinois plans to follow this summer. Other states - Missouri and Mississippi, among them - are in the planning or talking stages.

Tens of millions of dollars have been invested in the riverboats and boosters say the glitz and glamour - mahogany and marble bars, alabaster and crystal chandeliers - will help dispel Iowa's dour American Gothic image.

''It's going to give a little more dazzle to the area,'' said Larry Reed, executive vice president of the Davenport Chamber of Commerce. ''It's going to tell the world we're not all hicks in bib overalls that grow corn and pigs ... and have straw sticking out of our teeth.''

More important than image, though, are the greenbacks gambling will generate, especially here in the Quad Cities, a stretch of Iowa and Illinois along the Mississippi that lost more than 10 percent of its jobs in the mid 1980s.

It was the era of the farm crisis, a decade when a depression in the agriculture equipment industry crushed the region's industrial backbone. Harvester, Deere and Caterpillar struggled. Factories closed or scaled back. Unemployment soared into the double-digits. Folks moved away. The Quad Cities lost 8 percent of its population in the '80s.

''This area needs something, a shot in the arm,'' said Singbush, a 24-year veteran of Deere & Co., a farm machine manufacturer, who will be a gaming supervisor on the casino boat The President.

''The smokestack-type business seems to be going offshore,'' he said. ''A lot of people are waiting for it to come back. I don't think it will.''

Dellene Nicholson, a dental technician turned gaming supervisor on a competing riverboat, the Diamond Lady, also has witnessed good times and bad and is ready for another upturn.

''I've seen it when there's been an industrial boom. I've seen the absolute bottom of the pit,'' she said. ''The big question became 'What is this area going to do?'''

The answer, it seemed, was right in the back yard: the Mississippi, a majestic and mighty river, celebrated in story and song, a world-class tourist attraction just waiting for tourists.

The theory was if you build the boats, they will come. The local convention bureau predicts a million more visitors annually, pouring millions of dollars into hotels, restaurants and shops. The two riverboats set to sail from the Quad Cities have created about 1,500 jobs.

And the metamorphosis already has begun, says Chuck Patton, riverboat gambling director in Iowa's Racing and Gaming Commission, which has granted six licenses.

''We went down to the cities where we gave the licenses, and their riverfronts in most cases were in a bad state of repair. They were totally neglected. Their downtown areas had vacant buildings everywhere you looked,'' he said. ''You go to these areas today, there's hustle and bustle, there's construction going on, there's a lot of development going on.''

Steamboat Casino River Cruises, for example, owner of the new $10 million Diamond Lady, a paddlewheeler, has plans for a $57 million investment in the Bettendorf, Iowa, area, including a recreational vehicle park, a factory outlet center, an amusement center and a hotel.

Still, riverboat gambling - which will be dockside during wintertime - won't be a bonanza for Iowa. Annual tax revenues are expected to be about $11 million, Patton said.

State law limits bets to $5 and individual loss limits to $200 per cruise.

''At $5, this is not gambling. This is fun,'' said Gary Armentrout, gaming vice president for The President, touted as the world's largest floating casino - a five-deck, football-field-length boat with 27,000 square feet of gambling space.

''You're not going to get the hard-core gambler,'' Armentrout said. ''You're not going to get the high roller. You're going to get the recreational player.''

The limits, supporters say, reduce the likelihood of crime and prostitution associated with Las Vegas and Atlantic City. Riverboat owners say most tourists visiting the ''Mississippi Strip'' won't be habitues of gambling meccas, but visitors from a 300-mile radius.

''(But) if they're not competing with Vegas, they're not after the gambler's dollar, and if they're not after the gambler's dollar, they're not going to make the big money,'' said William Thompson, a management professor at the University of Nevada-Las Vegas.

Riverboat operators or towns may profit, he added, but ''it's not going to be a savior for the regional economy.''

''It will be a fad and a short-run gain,'' he said. ''But after two years, no. After people have done it with their family one time, it'll just be another thing on the map.''

Not so, say riverboat owners who note slot machines and games will be just part of the package, along with gourmet dining, Dixieland jazz and costumed workers evoking the Twain era when dandies wheeled and dealed in poker games while cruising the river.

''We're going to give them a gee-whiz experience,'' said Connelly, who owns 12 excursion riverboats.

Connelly has put his money where his mouth is, investing $10 million to remodel The President. ''It's a miracle what God and money can do,'' he boasts.

The riverboats will be rely on homegrown products and talent, from Iowa- produced pork and beef to Iowa singers, musicians and dealers.

Former car salesmen, housewives, farmers, dental hygienists and secretaries have learned the intricacies of blackjack, craps and roulette - an inviting change for many.

''You're going to work, you're getting paid for having a good time. How can you beat it?'' asked Miss Ritscher, a bubbly 21-year-old gaming supervisor who previously worked in a farm co-op.

''It's the Disneyland philosophy,'' she said. ''Everyone here will be a guest, not a customer.''

Ms. Nicholson, who lived in Peoria, Ill., until she was laid off, had never seen a craps table except in James Bond movies.

But this is her shot at a new life with a growing company.

''There's no reason in being humdrum looking forward to Friday's paycheck, if you don't enjoy Monday through Friday,'' she added. 'I've got nothing to lose, but everything to gain.''

''For 15 years, you cross the mighty Mississippi, you take it for granted,'' she added. ''Now it looks like this industry is really going to boom. I'm banking on it, really. ... I'm going to do this, until I can't count anymore to 21.''

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EDITOR'S NOTE - Sharon Cohen is the AP's Midwest regional reporter, based in Chicago.