— In their last joint appearance before next week's primary, Republican gubernatorial candidates on Tuesday hoped to cement farmers' and rural Minnesotans' vote at a FarmFest forum here, pledging to safeguard agriculture interests if elected.

They told about 1,200 farmers and others they would promote international trade of Minnesota crops and livestock, improve infrastructure to move goods and ease environmental regulations.

The contenders, Hennepin County Commissioner Jeff Johnson, Rep. Kurt Zellers, businessman Scott Honour and former lawmaker Marty Seifert, didn't try too hard to differentiate themselves from one another. Instead they aimed their broadsides at DFL Gov. Mark Dayton, who declined to participate in the gubernatorial forum. Hannah Nicollet, the IP candidate, also took part in the discussion. The governor, who is limiting his debate ­appearances until after Labor Day, will visit the three-day event on Thursday.

FarmFest has long been a proving ground for political candidates aiming to win over rural Minnesotans. Part trade show, part county fair, the event draws thousands interested in checking out the latest in agricultural technology, sampling food stands and, of course, learning more on candidates' positions on farm policy. Those views are important to ag operators in a state that ranks fifth nationwide in the value of its crop and livestock production.

In the nearly 90-minute forum, candidates offered their positions on topics that included the labeling of genetically modified foods, distribution of state dollars to rural counties and funding of agriculture education programs.

The candidates often agreed on policy questions with slight variations in how they would carry out their stated goals. What united them was their criticism that Dayton skipped the debate.

"This is one of the biggest and best agricultural outlets in the states," Zellers, R-Maple Grove, said. "He should be here with you today."

In a countermove, the Dayton campaign made public its endorsement by the Minnesota Farmers Union Political Action Committee. Dayton has "demonstrated a fierce commitment to Minnesota's rural communities, farmers and our state's farming tradition," said Doug Peterson, who chairs the organization. "From supporting renewable fuels to strong leadership on crisis issues like drought and propane shortages, Governor Dayton is a proven friend of rural Minnesota."

Dayton's campaign manager, Katharine Tinucci, said in a statement that the six debates Dayton plans would be sufficient to "provide Minnesotans with good opportunities to hear and compare the candidates' views."

Candidates at the show took questions from a panel of agricultural leaders and each had one minute to respond.

On the labeling of genetically modified foods, they said that it's important to have a blanket policy rather than a state-by-state patchwork of laws. That approach, they said, would make it costly for Minnesota food companies, such as Cargill Inc. and Hormel Foods Corp., to implement labeling requirements.

The candidates pledged to promote the state's agricultural industry abroad to boost exports. Zellers pointed to growing demand in China, a country with a burgeoning middle-class but a lack of ­arable land.

"Number one, you need a salesman as governor," Johnson said in response to a question on how to maintain a strong livestock sector in the state.

All the candidates also promised to invest in the state's roads and bridges to help facilitate the movement of the state's agricultural products. Honour said that if he were elected governor, he would approve the Sandpiper Pipeline, a $2.6 billion project to carry North Dakota crude oil across northern Minnesota into Wisconsin. That would help ease rail congestion caused by crude oil shipments, he said.

In addition to making policy pitches, some of the candidates touted their rural roots in an effort to woo farmers.

Seifert, who grew up in nearby Marshall, appeared to have a home-court advantage, eliciting the most applause from the crowd.

"I've stayed my entire life here," he said. "I'm not going anywhere. If I go to St. Paul, I'd be visiting there, not living there."

Greg Bartz, a 60-year-old corn and soybean farmer from Sleepy Eye, a town 30 miles southeast of here, came to the trade show specifically to attend the forum. Who the governor appoints as agency heads is important, he said, because farmers have to abide by state rules in the day-to-day operations of their business.

He thought the Republican candidates did well in Tuesday's forum but he singled out Seifert for his performance. "He seemed to be the most knowledgeable and more connected to the issues," he said.

He declined to say who he plans to vote for next Tuesday, but said the forum cemented his views on the GOP candidates. "I've been following the race, and I think the forum probably reinforced my thoughts that they are similar."