"a salient reason" is correct and can be used in written English.
It is often used to refer to a particular reason that stands out as being particularly important. For example, "A salient reason for increasing the minimum wage is to improve the quality of life for low-income workers."
They point to the disproportionate number of traffic stops of African-American motorists as a salient reason not to give law enforcement officials another excuse" to stop blacks summarily.
To make things more complicated, the risk of sexual assault and harassment of transgender females in male bathrooms is a salient reason for providing access to bathrooms according to gender identity, while many worry about transgender males being sexually bullied in male bathrooms.
A salient reason for advocating biodigestion as an alternative source of energy is that electricity is not available in all parts of this country.
As the above analyses suggest, the survivors in this sample spontaneously referenced negative experiences from initial disclosure attempts when describing their reasons for ceasing to disclose (even though this question was never explicitly asked, suggesting that this was an extremely salient reason for ceasing to disclose).
But in-depth interviews and surveys with women who freeze their eggs suggest that not finding a partner is an even more salient reason for delayed childbearing.
While I have read a few negative reviews about the wooden worktop, there are a few salient reasons why it can never really be beaten.
But in a book compiled for the exhibition, Michael D. Gordin, a history professor at Princeton, suggests that the salient reason was political.
Mitt Romney's supporters cite that same mess as the salient reason he's running.
Another salient reason why some economists believe the projections are low is that they exclude the city's cash economy.
This is because intentional harms can be condemned for another salient reason: the agent's malicious intent.
The most salient reason, though, was that one of his daughters — young Andre's sister — had been raped when he wasn't around.
