NASHVILLE (AP) - Democratic Senate candidate Gordon Ball on Thursday criticized incumbent Republican Lamar Alexander for refusing to participate in debates that would highlight differences on issues including abortion, education and guns.

At a press conference on the steps of the state Capitol, Ball noted that Alexander had found time to visit Vanderbilt University earlier in the week to discuss the Ebola virus in Africa, but has declined to make time to discuss matters more pressing to Tennesseans.

Ball called for public debates in Nashville, Memphis and Knoxville.

Alexander spokesman Brian Reisinger noted that the candidates are scheduled to make a joint appearance at a Farm Bureau forum in Cookeville on Oct. 16, a day after the start of early voting.

"Repeated comments by Mr. Ball and his allies denigrating the candidate forum are disrespectful to the Tennessee Farm Bureau's 650,000 members," Reisinger said in an email.

The early-morning Cookeville event is not open to the public and is unlikely to find a wide television audience.

"There's no give and take between Mr. Alexander and myself," Ball said. "It seems to me to that Mr. Alexander after his long history is doing a disservice to the people of Tennessee not to openly discuss matters."

Ball was joined by several supporters wearing t-shirts opposing a proposed constitutional amendment seeking to give the state Legislature more power to regulate abortions in Tennessee.

"I believe that issue is for a woman, her doctor and her god," Ball said. "Lamar Alexander believes it's for the Tennessee Legislature.

"That's a huge issue," he said. "Why aren't we debating that?"

Ball said another contrast is his opposition to Common Core education standards, which he said Alexander supports.

Ball, a Knoxville attorney originally from mountainous Cocke County on the North Carolina border, chafed at a recent F-rating f rom the National Rifle Association, calling it a "hatchet job" because he is a Democrat.

But Ball stood by his support for more detailed background checks in the aftermath of school shootings, because "no one wants to allow somebody who has a mental health problem to buy a gun."

"When I grew up, everybody carried a gun," he said. "I'm a Glock owner, I have two shotguns in my closet. To say that Gordon Ball is anti-Second Amendment is just ridiculous."

Ball in a weekend speech to Democrats made light of the NRA rating, issuing what he called a "challenge" to Alexander: "His piano versus my Glock."

Alexander, a former two-term governor who also ran for president twice, is a piano player who often played at campaign events and other public appearances.

Observers were quick to note that the Tennessee Constitution disqualifies anyone who fights a duel - or issues a challenge to one - from holding public office.

Ball laughed off those concerns on Tuesday.

"I was kidding, obviously, and said it in jest," Ball said, while noting that he was standing beneath a statue to President Andrew Jackson, who he noted "wasn't afraid to have a duel or a debate."

The Secretary of State's office didn't appear interested in getting involved in questions about whether joking about duel challenges would run afoul of the constitution. Spokesman Blake Fontenay called it an issue "best left for the courts to interpret."