Those are some great questions.
Please allow me to cut through everything, and tell you what we spray. Alan has a different spray program in NY, but the climate is different there. And we are spraying for commercially saleable fruit here, which is a higher standard than folks growing for themselves. Honestly, I don’t know what the standard is for Alan’s clients. Probably runs the gamut of pretty ugly to pristine fruit? I do think NY and the rest of the northern east coast have less pest pressure than we do here in the lower Midwest. I’m pretty sure about that.
Unfortunately, we here in central/eastern KS and MO get lots and lots of rain in the summer (unless it’s a drought) paired with lots of heat and humidity. Folks in GA have little weather to complain about, imo.
Here is our peach spray program, for a commercial orchard, with lots of pest pressure, because of the number of stone fruit trees:
We spray one dormant spray for leaf curl, sometime between Dec. and through Feb. We use chlorthalonil. We’ve found that is the most effective fungicide for leaf curl. We rarely see it with that one spray. Sometimes we’ve sprayed a sticker with it, sometimes not. Sticker seems to keep it on better, but it stays on pretty good by itself.
We don’t spray anything till just before shuck split. At about the day before shuck split (at this point we are scouting every day) we come in to combat plum curc. It’s a devastating beetle. The larva are legless. They are prolific and tough. Keep in mind, if we sell one peach with a P. curc. larva in it, we’ve lost that customer for life. They will also tell their friends about their experience with wormy yucky fruit. The whole thing is a little antipodean. In my experience, most customers want a no spray program for their fruit, but are utterly repulsed by internal feeding grubs, or even spotty fruit. I mention this so you understand customers drive the quality of the fruit.
Just before shuck split we come in with Actara or Belay (both neonics are murder on P. curc) along with a spray of chlorothalonil. Sometimes we will even mix a pyrethroid in the tank, along w/ Actara or Belay, to hammer stink bug (which starts to migrate at this time).
We will come in a week later (because this is the super pest time of the season) again with Belay or Actara. At this point we will mix Captan as a fungicide, to start to control peach scab. Remember that captan requires the water pH to be acidic, or it’s pretty much worthless. I add citric acid to the tank before captan is added.
This takes care of PC pretty good. If we need to come in later for PC (warm long spring causes PC to constantly migrate in the orchard) we will use additional sprays of Actara or Belay, up to the label limits. Again we will sometimes add a pyrethroid to kill stink bug more effectively. The pyrethroid can be something as simple as Mustang Maxx, or Warrior II. They sell homeowner products with the same ingredients.
Once we get about a month out of shuck split, the battle is largely over. Disease fungi are under control, PC is dead, brown rot inoculum is much closer to toast. We can kind of coast after that, with cover sprays every two weeks or longer, depending on the weather.
Note, I do all the sprays myself. I don’t trust anyone to run the airblast sprayer. As a side benefit, I can make sure all the trees are covered adequately with spray. Inadequate spray coverage won’t provide good protection on your trees.
