A former Countryfile presenter has told a tribunal she was warned "to be careful with those wrinkles when high definition comes in" just months before being dropped from the programme.
Miriam O'Reilly, 53, is seeking compensation from the BBC for alleged sex and age discrimination.
She claimed director Dean Jones' remark "was a reflection of the BBC's view that women on TV needed to look young".
The BBC has said it will "vigorously defend" the case.
Ms O'Reilly was one of several female presenters, including Michaela Strachan, then 42, and Juliet Morris, then 52, who lost their jobs on the show ahead of its move to a prime-time Sunday evening slot.
The show's main presenter John Craven, then 68, was retained. Former Watchdog host Julia Bradbury, 36, and Matt Baker, 32, were among the new presenters who joined the revamped programme.
In a witness statement given to the tribunal, Ms O'Reilly said Mr Jones told her in February 2008 that the advent of high definition could be "crunch time" for her career - a remark she said "sent a shiver down my spine".
"I do not believe that a man would be asked about his wrinkles nor offered hair dye," she added.
Ms O'Reilly said she was not told why she would not longer be required as a presenter, only that the show was being "refreshed".
"It is not an exaggeration to say that I was devastated by this news.
"Being dropped from the programme, I believe because of my age and sex, really affected my confidence.
"I thought I was going to be labelled as not being sharp, or vital, or even physically fit enough to make the programmes I was primarily involved with, because they were made outdoors in all weathers."
She said there was nothing in the new version of the show that she or the other older female presenters could not have done.
"Viewers trusted us because we had experience, knowledge and credibility. We brought a level of understanding to the programme that I don't believe exists now.
"The subject matter of the prime-time show hasn't changed, it's still very much identifiable as Countryfile. It's just that, overall, the presenter line-up is much younger - that's the most identifiable difference."
After she was dropped from Countryfile, Ms O'Reilly continued working on BBC Radio 4's Costing The Earth, but said she was surprised to be told by producer Maggie Ayre that she had been allocated an episode about pensioners.
"I actually laughed, thinking she was joking because so much was being made of the negative newspaper coverage regarding the Countryfile changes and the many accusations from BBC viewers that the corporation was ageist.
"I felt they gave me a programme about OAPs deliberately to embarrass me. I thought it was payback because it was believed I had leaked stories about the BBC and ageism."
The tribunal continues.