I lost all my mango trees from FL few years back but after using abound on newly delivered trees from FL, i spray and drench them with abound. As well as drench with seaweed and powder & pellet mycorrizae...
So far so good. No noticeable gummosis or phomompsis(dieback) for close to 2 years now.... i know i still have a long way to go since my trees are still on the juvenile stage.
Im no expert, however, im jst sharing on what i had observed.
Here are the mango varieties i lost b4 infusing abound 15gal carrie, 3 gal buttercream, 7 gal sweet tart, 3 15 gal lemon zests, 2 25 gal coconut cream & 3 gal guava & 3 gal taralay.