I have a few very small apple and fig trees. I planted the apple trees last year and had a huge problem with bug completely defoliating them. I bought some 'Bonide Fruit Tree Spray' and started spraying them with that as soon as I saw leaves start coming out. They did okay at first, but then I started noticing they were being chewed up. Upon closer inspection I noticed several of those little inch worms that hang from the trees.
I'm in SC, so I contacted the local Clemson College Agricultural Extension and asked them about it. He said they were canker worms and that I should use a chemical with 'spinosad' in it. Being very small tree, I can't make a small enough batch of the spray to use up, so I'm just leaving it in my sprayer with the pressure release valve open. If it gunks up the end, I'll just buy a new one. I don't think the spray I have contains spinosad, so I picked up a bottle of concentrate. I asked him if it would be safe to combine them, since I didn't have two tanks. He seemed to think it would be okay. He said to mix it in another container and something about if it wasn't warm, then it was okay to add it in. I don't know if he meant that I should mix the concentrate with some of the poison water I already had to see if it created chemical heat or what.
I want to know if you guys have ever combined sprays like this to ill effect? I can't remember the name of the spinosad concentrate I bought, but it was labeled as affective against canker worms, caterpillars, etc... It only container a very small amount of the spinosad, though. If I do combine them, I think I should probably use the full dose of each to the recommended amount of water.