First off those nugs look like shit, you never want brown bud. And secondly those "trichomes" that you see are probably mold spores (at least from the pic it definably seems to be in the early stage of developing mold). What's wrong with this bud well it hard to be sure but I'd say poor curing and old bud. Thc decreases with age and turns to a less potent, more head achy, cannabinoid. And molds no good either.