varietal responses to neem sprays

I planted 95 apples (nine varieties on G.30, G.969, MM.111 and B.118) in the last week of April, and finally managed to do my first spring holistic spray on Tuesday, May 29. This spray used the standard recipe (minus seaweed), which amounted to 1/3 c. neem, 1 1/4 c. liquid fish, 2/3 c. EM1 and 1/2 c. molasses in a 4 gallon tank - I used about 2 gallons on the apples and the rest spread between 100 young chestnuts and the garden. One week later, I noticed that the leaves on a few varieties (mainly Newtown Pippin and - especially - Dabinett) were looking scabby/rusty. I asked a local expert, who told me that this didn't look like CAR or scab, but was probably spray damage.

So was this due to a heavy hand in applying the holistic spray (even with 0.5% neem)? Has anyone else noticed a differential response to the same concentration of neem in a spray, where some varieties are fine and others end up with heavily-russetted leaves? I'm pretty sure I wasn't just extra-heavy on the Dabinetts and Pippins...

I'm sorry I haven't provided a photo here - if anyone has advice about uploading photos I'm happy to add one.

Willet, NY (Zone 5a)
100 semi-dwarf trees to be planted April 2018
(Farm name TBA)

I can confirm that Dabinett is intolerant of neem. I just accidentally sprayed mine with a holistic mix that included .5% neem. Past two years I avoided spraying neem on the Dabs and didn’t have a problem. Now, 4 days after spraying the leaves are bronzing up. Doh! Hopefully the damage won’t progress further for either of us. My Dabinett just can’t catch a break.

Nat Bouman
Growing cider varieties in Zone 5b
On B.118 at 18X24
Susquehanna County, Pennsylvania

I've killed a Dabinett with neem oil before. I usually spray at 5 or 6 pm but this particular time I sprayed in the early morning and I'm guessing a full day in the hot sun with the morning spray just roasted it.