REGALIA products are active against both soil borne and foliar pathogens, delay the development of resistance, and help minimize chemical residues. They can be used as stand-alone products or in combination with other fungicides to strengthen integrated pest management programs (IPM) and to help manage resistance in a wide range of organic and conventional crops, as well as in turf and ornamentals.
Regalia is BEST as a preventative.
Regalia is indicated for edible food crops; I have not seen any ornamentals labeling.
If one were to try using Regalia on ornamentals, as a foliar application, then apply this product at a rate of 2–4 quarts per acre when applied alone, or at 1–4 quarts per acre when tank mixed with another fungicide preventatively (in either case, use a minimum of 50 gallons of water per acre).
Avoid excessive amounts of water that result in spray material dripping from the foliage. Is best to use spreader-sticker with Regalia; yes, the yucca has worked well as such.
Per lack of label mention, does not seem to be corrosive to equipment; also, I have not heard anything negative from our clients to date.
The label does not say anything about Regalia being harmful to bees.
Make sure you use yucca spreader-sticker with Regalia.