You'll have to forgive me for not taking time to dig this up for you. This principle is so basic to disease pathology that when I see questions like this, I really have to wonder what on earth folks are getting taught in their high school biology classes. A significant reason why farmers do crop rotations is to control for the increased disease pressure created by growing monocultures like they do. It's also a significant reason why they spray toxins on the crops like fungicides. And a significant reason why GMOs exist, as a major thrust of those is disease resistance. It's well-established that disease risk is often (though not always) density dependent. This is biology/pathology 101, folks.
Oh, I see. You're using the term “dense monoculture” not as this:
Monoculture is the agricultural practice of producing or growing a single crop, plant, or livestock species, variety, or breed in a field or farming system at a time.
but as what the term “monocropping” usually refers to:
Continuous monoculture, or monocropping, where the same species is grown year after year,[2] can lead to the quicker buildup of pests and diseases, and then rapid spread where a uniform crop is susceptible to a pathogen. The practice has been criticized for its environmental effects and for putting the food supply chain at risk. Diversity can be added both in time, as with a crop rotation or sequence, or in space, with a polyculture.
https://en.wikipedia.org/wiki/Monoculture
Perhaps that's why you were having a problem digging it up.
BTW, I own a farm. They've been crop-rotating for as long as I've been alive.
I am unaware that any agency or company has recommended monocropping genetically modified crops. Just the contrary.