LITTLE ROCK, Ark. (AP) — The Latest on Monsanto's effort to overturn Arkansas' ban on its dicamba weed-killer (all times local):

2:50 p.m.

An Arkansas judge has dismissed a company's challenge of the state's ban on a controversial weed killer, citing a state Supreme Court ruling that has made it more difficult to sue the state.

Pulaski County Circuit Judge Chris Piazza on Friday dismissed a lawsuit by Monsanto challenging the state Plant Board's decision to ban dicamba's use between April 16 and Oct. 31. Monsanto was also challenging an earlier rule that specifically targeted its brand of dicamba.

Piazza cited a recent Arkansas Supreme Court decision that said legislators could not waive the state's immunity from lawsuits — an immunity granted under the state constitution. The judge said he did not see how the justices' previous ruling would let Monsanto's lawsuit to go forward over the dicamba ban.

Arkansas regulators last year received nearly 1,000 complaints about the weed killer.

1:15 p.m.

An Arkansas judge is hearing arguments over a company's efforts to prevent the state from banning an herbicide that farmers in several states say has drifted onto their crops and caused damage.

Attorneys for Monsanto asked a Pulaski County judge on Friday to issue a preliminary injunction preventing the state from enforcing a rule banning the use of dicamba from April 16 through Oct. 31.

The St. Louis-based company is also asking that an earlier rule banning dicamba be blocked.

Attorneys with the state have asked the judge to dismiss the company's challenge to the ban.

Arkansas banned dicamba use for part of the year after the state received nearly 1,000 complaints last year about the weed killer.