Grain boss to run for Katter in NSW Katter's Australian Party has selected Peter Mailler as its NSW Senate candidate at the election. FORMER Grain Producers Australia (GPA) chairman Peter Mailler will be the NSW Senate candidate for Katter's Australian Party at the September election. Mr Mailler stepped down as GPA chairman in January to focus on his family farm business, south of the Queensland border near Goondiwindi. He was GPA's inaugural chairman after it replaced the Grains Council of Australia as the peak body for the industry in August 2010.