By Greg Stutchbury
The 16-year-old, who partnered Andy Murray to the Hopman Cup final before the year's first grand slam, had also reached the quarter-finals of the women's doubles main draw with Australia's Sally Peer.
"Starting with Perth, getting to the final there, then quarters of doubles, then getting to the final here -- I've played a lot of matches," Robson told reporters.
"Just a bit exhausted with it, everything. So I think now it's just good to go home.
It was the second successive year that Robson, who beat Pliskova's identical twin sister Kristyna in the semi-finals, had lost the Melbourne Park final after she was beaten by Russia's Ksenia Pervak last year.
In the first set, left-hander Robson was unable to cope with the tall Czech's groundstrokes, making a series of errors.
"My sister give me something and coach also, so I know everything about her," the 17-year-old Pliskova said.
"I think in the first set she played bad. Not bad, but so many mistakes. In the second, she was better."
"I think it was maybe he was a little bit nervous to play, you know, the final with the Australian people," said Fernandes.
(Editing by Peter Rutherford)