Because our neighbors Thuja hedges have our Birnbaum has been repeatedly attacked by pear rust. The fruit approaches atrophied and fell off. So far, we have always been skeptical about chemicals in the garden. But Compo-Duaxo should not be toxic bees, and it solllen no residues remain unaffected in the fruit. 2013, we have right after flowering so that injected (only once, you should actually 2-3 times spraying). We have then for the first time harvested pears, moreover, a hell of lot. Even bought a dehydrator, because we no longer know where to put it. So, we can only recommend Compo-Duaxo!