I sprayed at 2.5 gm/gallon (a bit under .1 oz/gallon. You had recommended .04 oz/gallon on the Avaunt vs Imidan thread, I ran this by my extension guy, who told me, “Follow the label.” Yes, right.
My logic us that the recommended rate is 6 oz/acre, where anywhere from 50 to 200 gallons should be applied to an acre. My orchard I paced out at about 1/3 of an acre. Because I am using a hand-pump sprayer, I go through about 20 gallons to cover the entire orchard, which works out to 60 gallons/acre, at about the low end of the range. 6 oz in 60 gallons works out to .1 oz/gallon or 2.8 gm/gallon. – I rounded down to 2.5 gm/gallon, 5 gm for a 2-gallon sprayer charge.
I made two applications early in the season – one at petal drop and a second two weeks later when Extension was saying they were trapping codling moth nearby. A third application went on in mid-to-late July when I spotted my first maggot fly. Some time in late August, Extension warned that both moth and fly were flying, but I didn’t find rain-free weather when I was up there.
When I told my extension guy I had purchased Avaunt for this season, we warned me it was less effective “on your late-season pests”, I guess he meant apple maggot fly. The label warns that it is less effective on maggot fly – they describe the problem is that the maggot fly can feed on unsprayed trees outside your orchard and then fly into your orchard and lay eggs before the adult female takes a bite to eat. I have untreated 100-year-old-trees some distance from the orchard on the property line.
Mindful of the potential reduced effectiveness of Avaunt against maggot fly in my situation, I added some of my dwindling stock of Ortho Flower Fruit and Vegetable Insect Killer Concentrate to the tank mix, and the Avaunt label says is is OK to blend other insecticides. I reserved this for the late July spray for my earlier-season apple trees that attract the maggot fly.
I could purchase the commercial version of acetamiprid in the form of Assail. I have already spent $160 on the 18-ounce quantity of Avaunt, which should hold me for another 2 seasons, that is, if it works.
Assail 30 WG runs about $250/64 oz, where 4 oz is the upper range of the application rate per acre, which at 3 applications/season works out to a 16 season supply for my small orchard. It’s not just the money, at my age, I have to figure on whether I can stay healthy for another 16 years working the orchard.