Flourish Pixel

Remove/Exclude specific categories from site RSS Feed. You just need to install this, then place your category id in it’s option page and save. That’s all. If you want to exclude more than one category, then place them one by one and separate them by comma.
For Example: -1,-2
**Note: you must need to use minus sign (-) before category id.

FP RSS Category Excluder

Remove/Exclude certain categories from site RSS Feed.

Michael Adams (mdawaffe)

Just One Category will cause WordPress to display on a category archive page 
only those posts which are direct members of that category, i.e. this plugin 
will exclude from that category page all posts which belong to any of that 
category’s subcategories but do not belong to the category itself.

Just One Category

On a category's archive page, displays only the posts directly in that category, not in any sub-categories.

FP RSS Category Excluder vs Just One Category