Jimmy Wales wrote in part:
If there's ongoing genuine controversy, then perhaps it's necessary for even the vegetable crops article to say something like "Roundup has seen increasingly widespread use on fruit and vegetable crops each year since 1995. There has been some resulting controversy, which is covered in more detail in the article on [[Roundup]]."
(Stylistically, that's a bit odd, because we usually write each article as self-contained and without mentioning other articles.)
Personally, I think that this is a bad idea. Most of the time, a [[wiki]] link to another article will be fine; even in this example, beginning the sentence with "[[Roundup]] has ..." is probably plenty good to let people know where to go for more detail. But in some cases, it's not clear to the reader (especially to a newbie) where discussion of some further point may be found. This is especially true when there was controversy among Wikipedians as to whether some material should be on a certain page or another. So in some cases, an explicit link to some other article (along the lines of "For more on this, see the article [[X]].") can be a very helpful edit.
-- Toby