The phrase "reduce variety" is a correct and usable phrase in written English.
You can use this phrase when the context calls for reducing the variety of something, such as when discussing strategies for streamlining a process. For example, "One way to increase efficiency is to reduce variety in our workflow."
What most fad diets have in common, beyond calorie restriction, is reduced variety.
Under forest canopies where it doesn't have to compete with similar shrubs that need more light, Berberis thunbergii can form thick stands and displace native plants, reducing variety in wildlife habitat and forage.
In a military environment, superior intelligence offers battlefield commanders greater control because this necessarily reduces variety (i.e., uncertainty).
He reduced variety latifolia to synonymy with variety sphaerocarpa, but conceded the species needed further review.
33 Some groups were smaller than intended, with fewer women than arranged able to attend, which may have reduced variety of input, but not depth of discussions.
Although the degree of focus seemed less important in predicting higher efficiencies or timeliness, a higher degree of focus indicates reduced variety.
This is one reason the company felt it could further reduce product variety to cope with the recent economic crisis.
They are more efficient users of resources than the weeds but reduce the variety in the system, eventually making it brittle and vulnerable to sudden change.
By carefully balancing the cost savings from economies of scale in manufacturing against the possible loss of sales, the category manager and the local managers were able to reach a consensus on how much to reduce cap variety.
"We can outsource the cleaning and make the drivers independent contractors," she said, "and we can cut the least profitable delivery routes, least profitable accounts or reduce the variety of items we create".
