This week brings the dog shows and skillet throws, tractor pulls and spinning wools, oyster shucking, horse bucking, burger making and prize taking that make up the 145th annual Martha's Vineyard Agricultural Society Livestock Show and Fair - better known in a single breath as the ag fair.

The festivities begin Thursday at 10 a.m. at the agricultural hall in West Tisbury and close on Sunday at 7 p.m.

"It brings the whole Island community together," said Eleanor Neubert, fair manager and secretary of the agricultural society. "All summer long when I'm out and about in public - and especially grandmothers and mothers with their children - they will say children are crossing off the days until fair time. It's just the highlight of summer."

There are as many agricultural fairs in Massachusetts as there are cards in a deck, but the Island fair has long stood out.

"We're considered a medium-sized fair," Ms. Neubert said. "When the state comes down to do their inspection, they're amazed at the quality of the exhibitions - and the quantity as well."

So perhaps it's fitting that this year's theme is the Best Under the Sun, named after the winning artwork by Janice Haynes that will be featured on the fair poster, booklet and T-shirt. The image includes a table full of blue ribbon items - a flower arrangement, a pie, fruit preserves, a pumpkin, tomatoes and a quilt - under the giant, umbrella-like canopy of a first-place sunflower.

"People take pride in their exhibits and some people are thinking about them and working on them all winter long," Ms. Neubert said. "When the gardeners order their seeds, they're sometimes thinking fair - what will be ripe right at fair time."

The schedule of events is packed for four days, and aside from Sunday, the fairgrounds will be open 10 a.m. to 10 p.m.

At 10 a.m. on Thursday, the ox show, exhibit judging and goat judging start simultaneously. The exhibit hall opens once the judging is completed. The Blue Hills Brass Quintet will roam the fairgrounds, playing music on Thursday and Saturday. A puppet show new to the fair will begin at 11 a.m. on Thursday. The ox pull starts at 11:30, followed by the pet show at 1 p.m., a hip-hop demonstration on the stage from 2:30 to 4:30 and the Martha's Vineyard Swing Orchestra later that night.

Friday includes the Dale Perkins Horse Show at 11 a.m., sheep judging at 11:30, the draft horse pulling contest at 1 and the clam and oyster shucking and fish smoking contest at 4. The Texas swing band the Blue Strangers and Island musicians including Maynard Silva will also grace the stage throughout the day.

The first antique tractor pull to take place at the fair begins at 10 a.m. on Saturday.

"It compares very well with the horse pull," said Dale McClure of Oak Bluffs, who organized the event. "We pull a stone boat with concrete slabs."

A boat?

"It's a sled that's right on the ground that years ago - when you had a team of horses - that's what you'd use to get the stones out of the fields," Mr. McClure explained. "That's how a good many stone walls were built."

The competition is starting small with two weight classes for the tractors, including their drivers: 1,000 and 1,500 pounds, which are considered lawn tractors. In coming years, there will be more classes, Mr. McClure said, encompassing small farm tractors and then larger ones - 2,500, 4,000 and 6,000 pounds. He estimated that the heaviest tractor on the Vineyard weighs 12,000 pounds.

After seeing tractor pulls at other agricultural fairs, Mr. McClure decided he wanted to bring the event here, "just to get more interest and things for people to see - especially the younger people, the kids, the teenagers - and try to get them involved in the fair a little bit," he said. "Our fair here - even though it's over 100 years old - is growing."

The pulling is done on a concrete pad, so participants have equal traction. The drivers have two minutes to pull the boat six feet. Mr. McClure built the pad with the help of David Steere and John George. Goodale Construction donated the concrete and Watercourse Construction did the prep work.

The horse show is again in the show ring at 11 on Saturday, and local act Toe Jam and newcomer Li'l Anne and the Hot Cayenne perform on stage at various times throughout the day. The 30th annual woodsmen's fair starts at 1 p.m., showing feats of strength and sawing, throwing and axing prowess in a dozen events including the horizontal log chop, tree felling, log rolling and chain saw sculpture.

There is still time to register for the dog show and the women's skillet throw, which take place on Sunday, at 10 a.m. and 3 p.m. Registration for the dog show begins at 9 o'clock before the show and registration for the skillet throw is open until 1 p.m. the day of the event. Registration for the exhibits and livestock closed yesterday evening at 5.

"Today's an extremely busy day," Ms. Neubert said yesterday over the phone from the agricultural hall. "We have people lined up out there filling out entry forms. We have a 14-foot table and it's filled up with people filling them out - and the fax machine is humming with entries coming through."

Meanwhile, the fair is literally rising up around them.

"The carpenters are busily working on the hall," she said. "The stage is up, the carnival rides are going up, the Ferris wheel is going up, some of the kiddy rides are going up."

In the exhibit halls, there will be competitions in categories from baking and flower arranging to fruits, vegetables, canning and preserving. There will also be artistic competitions in many categories, among them painting, handicrafts, photography and needlecraft.

Ms. Neubert said she has been hearing buzz about a record number of quilts this year.

"It must have been a winter for that," she joked. "Somebody said that TV must not have been good."

On the other hand, it was a mediocre year for crops, Ms. Neubert said.

"We've had more people complaining about their flowers and their gardens and their vegetables," she said. "The weather's been terrible for growing things this year - well, I shouldn't say terrible." There will still be many beautiful and impressive entries despite the fungus-friendly high humidity of this summer.

There will be junior-level competitions in many of the same areas, in addition to a nature component that includes collections of shells, fossils, flora, feathers or insects. "Anyone using poison ivy, poison oak, poison sumac will be disqualified and itchy," the rule book warns.

Dairy cattle, beef cattle, goats, swine, sheep, poultry, waterfowl and wildlife will fill the livestock barn for the adult and junior competitions. There will be working dog and sheep sheering demonstrations in the fiber tent every day, as well as demonstrations of weaving and spinning.

Despite all these attractions, the food alone has been known to provide sufficient reason to pay the $8 entry fee: fried dough, tempura and burgers cooked by firemen, are just a few choices.

"We look forward to fair food," Ms. Neubert said. "We've had many discussions already as far as what we're going to eat first."

The agricultural hall is located on Panhandle road in West Tisbury. Tickets are $8 for adults and $5 for seniors over 62 and children between five and twelve. Children under five get in free. For more information, call the agricultural hall 508-693-9549.

Due tomorrow at the hall between noon and 5 p.m. are all nonperishable hall entries, all junior entries and adult perishable entries. Adult perishable entries may also be brought before 8:45 a.m. on Thursday. Eggs and butter should be brought to the hall by 9 a.m. on Friday. All entries must be removed from the hall between 9 a.m. and 1 p.m. on Monday, August 21. All animals should be brought in between 7 and 9 a.m. on the day they are judged. The animals must remain on the fair grounds until 3 p.m. or they will forfeit any prize money they might receive.