Managing fungicide/pesticide for trees that bud out at different times?

[badatusernames]

Curious what people think on this one....

I have chojubai as well as Chinese quince. They tend to bud out early, and lo and behold, this year is no different.

None of my other trees are really budding.

1) I put insecticidal soap on my trees a week ago - the plan had been to spray lime sulphur in a month, because lime sulphur can react with the soap. Is this concern true for other fungicides?

2) Bjorn recommends spraying with Subdue Maxx as plants start to leaf out. Would you separate the quince and spray now? Or wait and spray when the others start budding out? Maybe Immunox would be better for cedar rust that can impact them, though.

#1 is more of a concern for tree health - I don't want to damage these, and it's the most important to me. #2 seems like it has more wiggle room, and I suspect spraying the quince now would be ideal, so long as #1 isn't a problem for them.

I assume no lime sulphur for the quince, because it would damage the leaves (I've never done it, so please correct me if I'm mistaken in thinking this).

Thanks for any thoughts!

 

[Wires_Guy_wires]

1) yes absolutely. Lime sulphur is a mixture of calcium, magnesium, oxygen, dioxite, hydroxide, and sodium (together: lime) and sulphur/sulphate/sulphite. If your fungicide or insecticide is water soluble, you can assume that salts will have an effect on it.
What that effect will be, is difficult to estimate without a chemical degree.
Soaps can help reduce surface tension and because they're usually made from some kind of potassium and oil, they will affect both water soluble and oil soluble -cides. This effect is usually not a big issue though, as plants themselves can produce soapy compounds when it rains and most whatevericides are made with that in mind.

2) I'm not sure what the best approach would be but my logic says to spray them at different times; whenever they bud or leaf out. Most sprays can keep pretty well when kept dark and cool.
I'm not a fan of preventative spraying, since most rusts that have apples and quince as intermediate host, the temporary damage - as far as I can remember - to them is mostly aesthetic and lasts just a single year. If anything, I'd spray the junipers instead, as they're the final stage (and do get visible long lasting damage) and the they're spreaders of new spores.
Especially since quince flowers early, I'd be sad for all the bees that I'd kill. Most fungicides are notorious for killing a bunch of bees. But bees don't usually go after juniper pollen, so spraying those would be less wrong in my book.
Something worth considering if you want!

 

[badatusernames]

1) yes absolutely. Lime sulphur is a mixture of calcium, magnesium, oxygen, dioxite, hydroxide, and sodium (together: lime) and sulphur/sulphate/sulphite. If your fungicide or insecticide is water soluble, you can assume that salts will have an effect on it.
What that effect will be, is difficult to estimate without a chemical degree.
Soaps can help reduce surface tension and because they're usually made from some kind of potassium and oil, they will affect both water soluble and oil soluble -cides. This effect is usually not a big issue though, as plants themselves can produce soapy compounds when it rains and most whatevericides are made with that in mind.

2) I'm not sure what the best approach would be but my logic says to spray them at different times; whenever they bud or leaf out. Most sprays can keep pretty well when kept dark and cool.
I'm not a fan of preventative spraying, since most rusts that have apples and quince as intermediate host, the temporary damage - as far as I can remember - to them is mostly aesthetic and lasts just a single year. If anything, I'd spray the junipers instead, as they're the final stage (and do get visible long lasting damage) and the they're spreaders of new spores.
Especially since quince flowers early, I'd be sad for all the bees that I'd kill. Most fungicides are notorious for killing a bunch of bees. But bees don't usually go after juniper pollen, so spraying those would be less wrong in my book.
Something worth considering if you want!

Awesome, thank you! I actually didn't think about the bee issue as I hadn't seen them on my chojubai before (and I've not seen my Chinese quince flower before), but that's a really good point.