urea is usually available at most garden/feed stores. generally comes as white granuals but is readily water soluble.

I have heard this for scab as well. Did you come across a recommended concentration?

The urea that is used as foliar spray is a different product and is available at outlets that supply commercial growers. I'm sure there must be a source on the internet.

Spreading the granular and letting the rain dissolve it should work as well as spraying.

Commercial apple growers often use the foliar urea in spring (from tight cluster to pink, of blossoms) to give the spur leaves a quick shot of N to help them size up and produce bigger fruit. I don't think it's really worth the effort in a home orchard.

A ground application now should get the N into the small wood for use in spring. Not sure how much it will help if you are unaware of nutrient status of trees.

I think what mes111 was referring to (or at least what I have seen referenced before) is a post leaf fall spray to the ground litter. It is supposed to help break your scab cycle by getting infected leaves decomposed before spring. Mowing them to mulch them up is supposed to help too.

I don't know if you would get any side benefit of absorption (N) into the trees that late?

I could see where granular application might not work as well as the idea is to hit the leaves not the soil? But urea is supposed to volatilize pretty fast when not incorporated into the soil (or carried down in solution)...perhaps the dry leaves absorb and bind the N short term while the decomp gets going?

Yeah, had my evening ale before answering question- should have read the post more carefully. Your advice is correct, Windfall.

I doubt doing this will make a noticeable difference in scab pressure but if you are trying to grow apples without fungicide I guess it might help. If you are using myclobutanil to control scab I wouldn't bother and I don't.

In a huge orchard the effort would likely have much more impact.

The post-911 regulations in this state (SC) unfortunately prevent my laying hands on urea for that very purpose (though for pears). When in neighboring NA or GA I look for it but so far unsuccessfully.

Are you sure urea has been banned? I think it is essential for farm use and must be available from their suppliers. Most lawn fertilizers have little more than urea so you can always run with that but it costs more.

It was banned along with ammonium nitrate for its (alleged) explosive danger. Legit farmers can get commercial quantities, just like ammonium nitrate. Regular folks like me can get mixed fertilizers with abundant urea in them but could never get it through a sprayer without some excellent filtration after dissolving.

I think that must be state by state, you can certainly buy 50lbs bags of urea granuals here at any farm store.

Yes, commercial quantities in urea are 50 pound bags here as well.

I thought scab was less an issue a far south as you are. Why even bother with this method- you can always blow the leaves into a pile, throw on some lawn fertilizer, water in and throw over a tarp and make compost while eliminating any scab spores on the leaves from reaching trees.

Was scab bad for you last year? I think that's the only situation where you should worry about the leaves in the first place.