They state that manure should never be planted with or topped dressed on anything grafted on Trifoliate Citrus. They state that manures cause it to become sick and the plant yellows. It has to do with the nitrogen availability. They suggested manures can be used to fertilize, but that sulphur must be added along with it. The Trifoliate needs to have same ph as blueberries, so an acid loving fert or fert with sulphur must be used to maintain low ph.