I've been told to follow up an infestation of apple scab by composting any leaf litter on the orchard floor to destroy spores. I plan to haul away most of the leaves to my garden composter but a 5% urea solution is indicated for the orchard floor. How much should I need per mature tree (10 ft diameter drip line) and are there any safety concerns with preparing the solution in a sprayer tank?
I figure 5% urea solution is about 2 lbs (pounds) urea in 5 gallons. It comes from my coop in 50 lb bags of prills.