Dr Steve Jefferies has been appointed to oversee Grain Producers SA's operations, following chief executive officer Caroline Rhodes' confirmation that she has nominated for preselection as the Liberal candidate for Schubert.

Dr Jefferies joined the GPSA Board in July and brings a wealth of experience in agricultural leadership, having served as CEO of Australian Grain Technologies and most recently as the managing director of the GRDC.

"GPSA has some exciting projects underway, including a series of trade and market access workshops to be delivered across regional SA next month, so it is business as usual for the team," GPSA chair Adrian McCabe said.

GPSA's constitution is apolitical and clearly states that no person who has nominated for election to a house of state or federal Parliament shall act as an officer or director of the company.

"The GPSA Board will wait with great interest for the result of preselection to determine next steps for our organisation. Caroline has been a tremendous leader for GPSA and has our full support," Mr McCabe said.

"In the meantime, our staff are looking forward to working closely with Steve over the coming weeks to deliver high quality training for our members."

Ms Rhodes will return to work on Monday, February 15, following the conclusion of the preselection process, which is now an internal Liberal Party matter.

The change comes as last month Primary Producers SA chair Rob Kerin announced he would be taking three-months leave because of "perceived conflicts" with his new role as project chair of Portalis - the proposed deep sea port at Cape Hardy on eastern Eyre Peninsula.