A can of Pedigree Chum is one of the prize exhibits at the Whitechapel Open, sponsored by The Independent. John Windsor previews the shows that could turn today's dog food into tomorrow's Saatchi must-have
The biennial Whitechapel Open and Open Studios, co-sponsored by The Independent, launches on Saturday 28 March. That means 60 days during which the East End, where the majority of London's 11,000 artists live and work, throws open its doors - polished glass portals at the Whitechapel Gallery, perhaps chipped and paint-smeared clapboard in the 46 participating "artists' spaces"- to collectors hoping to snap up the work of future Turner Prize winners before Charles Saatchi gets to them.

Fat chance. Saatchi is in the vanguard of a trend, much in evidence at this year's Open, away from conceptual constructions and back to painting (installations are in any case not accepted at the Open). He has been bulk-buying the kitschy, photo-precise, slightly distorted oils of Nicky Hoberman, who has on show My Precious, showing five little girls aged about five to seven with nine puppies. He telephoned her when she was convalescing in bed, broke and miserable after an appendix operation. He managed to convince her that he was the real Mr Saatchi only by turning up in person and buying 11 canvases.

Since then, Hoberman, now represented by Cork Street's Entwistle Gallery, has shown in Chicago and Sydney and had a sell-out in Boston in January. Some viewers remarked that her work had paedophile appeal. "Just a sign of the times," sighs Hoberman, a 30-year-old graduate of Chelsea College of Art and Design.

If her work does have perv-appeal (after all, Jake Chapman, co-creator of penis-nosed children, told her: "You'll go to prison before we do"), then it bucks a trend that Julian Opie, one of the Open's three selectors and renowned Turner nomination refusenik, has noted: a reaction against sex-and-violence. Of the 900 submissions (of which 100 were selected), only one, a video, used sex to shock. The selectors simply didn't like it. Hoberman's huge canvases (My Precious is 7ft high and 9ft wide; her prices vary from pounds 2,200 for the smallest to pounds 12,000 for the biggest) also defy the trend towards smaller pictures.

There's plenty of humour about. Not clever-clog art-historical irony, but simple funnies. Any work that made all three selectors laugh out loud, Opie reports, got in. Such as Matthew Bradshaw's meticulously salvaged contents of a can of Pedigree Chum dog food - at pounds 200 the Open's most unsellable artwork. Opie, poring over aspirants' photographic slides with the other selectors, remarked when he clapped eyes on it: "You can't possibly have that in the Whitechapel!" So it was selected. Well, look at it. Shiny-bright, with precisely preserved can imprints like ceramic throwing rings. Beautiful.

Worries about pong evaporated when Bradshaw assured the selectors that the smell lasts only 10 minutes after a can is opened, and promised to store 59 replacement cans in the Whitechapel Gallery's fridge - after a day, the moisture in the jelly sinks to the bottom, the top shrivels, and the whole chunk turns black. He will open a new can daily by the technique he discovered after sawing and hacking fruitlessly through 40 cans of various brands: pierce one end to remove vacuum then slice off the other using one of those can openers that cuts below the rim. Then, easy does it.

Bradshaw calls the work Unheimlich (uncanny). He did not want the pun to be too in-your-face. He speaks no German (but does, of course, have a working knowledge of Freud's theory of the uncanny and Hal Foster's critique of Surrealism). He is aged 25, unemployed, the son of a retired bus driver and a graduate of Surrey Institute of Art and Design. He did not disclose his college on the entry form, fearing that the selectors might prefer well-connected Goldsmiths or RCA graduates. But the Open is not like that. As Opie puts it: "We don't worry who the artist is, what they've done, or what they're going to do next."

But for the buying public, the advice is: know your artist. Bradshaw, for example, has never been exhibited before - "I designated dog food as art, they designated me as an artist" - but has plenty up his sleeve besides Pedigree Chum. How many other exhibitors have a successful career in art ahead of them?

At the Open, you can talk to artists, drink their wine - whose quality tends to be uncannily proportional to the quality of their art - and invite them to dinner, to be unobtrusively interviewed. In fact, you may never get to the bottom of an artist's work just by looking at it. Without chatting to 29-year-old Lucy Wood, would you guess that the zinc-plated tubular steel of her Fatal Entrapment, a skeletal, 2m-long death-trap of a car, is actually a playground climbing frame condemned as unsafe. Models like hers, rather than sculptures, are typical of this year's Open. Fatal Entrapment is pounds 3,000.

Or ask Jennie Boulter, a 31-year-old Camberwell School of Art graduate, why she creates images of pillared four-poster beds in exotic surroundings with Giottoesque trees. It turns out she is a trained physiotherapist who spent four months lying on her tummy in bed with a slipped disc after carelessly allowing a patient to fall on her. During that time, she tapped away at a computer, learning umpteen graphics programs. Her dream-like fantasy, Bed With Early Italian Tree (pounds 130, edition of 60) is a computerised colour ink-jet print on canvas. The bed's coverlet, by the way, replicates the rug on Freud's analytical couch.

Yes, psychology is in, as is high-tech computer-enhanced photography (and photo-realism in general). What Opie describes as "clean and tough- looking" images are clearly the coming thing. Computer-enhanced Cibachrome or ink-jet pictures bled off on to stainless steel or aluminium mounts are particularly trendy. The no-nonsense Nineties look, perhaps? There is certainly not much grungey art - tacky collages of found objects, autobiographical scribblings. Tracey Emin might find herself the sole exponent of that genre.

Nigel Ellis's National Trust (Cones), one of a series of ink-jet prints mounted on aluminium, features photographs of plaster-cast cones - cleaned up by computer - shot against posters of National Trust landscape. They are cool, icy-looking, and appear by optical illusion to be about 18ft high. Price pounds 890 in editions of five. Ellis, 36, is holding his breath before embarking on a pair of 10ft high wedge-shaped steel sculptures for Goodwood Sculpture Park with the meditative title, Mindfulness of Breathing.

Kate Belton, 25, an RCA graduate, has mounted on aluminium a Cibachrome photograph of a scale model of her studio that looks both precise and painterly. Price: pounds 2,400.

The tiniest sculpture is Correction by Matthew Thompson (31, RCA), a 7cm high, actual-size Tipp-Ex correction fluid bottle, in marble, carved and turned by hand. Not his hand, though. He found a man to do it. The three first attempts broke at the neck and cost him pounds 400. Now the craftsman wants nothing more to do with arty Tipp-Ex and Thompson has been on the phone to Carrara in Italy, seeking someone who will make him a Quink ink bottle out of black marble. The Tipp-Ex bottle is priced pounds 1,000.

Balloon sculpture, rather more traditional fare, is in an exhibition of 31 artists' work at Canary Wharf, this year's addition to the Open, selected by Canary Wharf Arts and Events, those people who gave the business and commercial centre the playful and inscrutable text panels of veteran conceptualist Lawrence Weiner, and Mark Wallinger's mad carousel of model railway trains.

The balloons? Surely not poodles. But yes, Frankie Sinclair (30, Central Saint Martin's) has glued together 300 of them, a deliciously kitschy 8ft high conglomeration, one of three balloon sculptures. She had hoped her doggies would be allowed to gently mock the pristine marble corporate precinct of Canary Wharf, but eyebrows were raised and they were re-sited in the shopping area. Few people have been cruel enough to pop her balloons. A subtler means of extermination, by anyone who really cannot abide them, would be to turn up the heating - the low-temperature glue melts above 25C.

Video art is not prominent. But among the six monitors (three at the Whitechapel, three at the Tannery), you can find Susan Morris's 80-minute loop, Fiction. A couple on a wall are filmed from afar, talking and gesticulating, by four different cameras, front, back and sides. The video replays the same 15 seconds of action as seen from each camera before moving on. It's a mesmeric experience of real time and the truth of the moment. Psychology courtesy of Adam Phillips's On Kissing, Tickling and Being Bored. Morris (36, Goldsmiths '91) has made a dozen videos. If you buy this one, pounds 450, edition of three, it will be the first she has sold.

You can visit established names in their studios, such as the "Sensation" artist Simon Callery (4 April) and the grandfather of East End art, Albert Irvin, now 75 (19 April). He is mercifully beyond trends, still painting massive, expressionist abstracts. It was Irvin who, with Bridget Riley and Peter Sedgley, set up Air and Space in 1968 at St Katherine's Dock, now the site of the Tower Hotel, and began helping artists to find cheap studio space in disused warehouses. Since then, the developers have moved in. But Space (the ponderous acronym of Space Provision, Artistic, Cultural and Ethical) is still going strong. It has acquired 15 sites, accommodating 350 artists and intends to celebrate its 30th anniversary with vigour.

Irvin blames Mrs Thatcher for the shortage of jobs in art education, the bread and butter of the struggling artist. "It's good that there's such ambition among today's young artists," he says, "but God knows how some of them are going to make a living. They'll not all be able to open restaurants in Greek Street"

For dates of the Whitechapel Open's gallery and studio openings and lectures, send an A4 size SAE and cheque or postal order for pounds 1 to the Whitechapel Gallery, Whitechapel High Street, London E1 7QX. Recorded information: 0171-522 7878. Other enquiries: 0171-522 7888