Good eye! I treated the fertilized one for plant bug as well because it was in really rough shape. Customer only wanted to treat 2 of them but after seeing the results now he wants me to treat the rest. I think the plant bugs are about done munching though? Maybe just fert for now and plant bug treatment earlier next spring.
I have dabbled over the past 10 years with southern organics, nu-arbor, & doggett products. My conclusion from seeing results is that urban trees benefit greatly if common sense is used to select a mix for each scenario. Especially in newer subdivisions with nothing but sub soils.
I've found trees respond quite well to amounts of nutrients that are actually lacking and in amounts well below recommended STANDARDS and practices. Long term, I want big ol mulch rings around trees to reduce if not negate fert use.
Im also intersted in the biology and chemistry found in forest soils vs urban and grassy types. Party why I use more humates and compost extracts/my weird secret conconctions than synthetic ferts.
Manganese still exasperates me at times but I deal with pretty lousy sites more often than not and acid prefering woodies.