Spraying a light concentrate of minerals every three weeks in growing season, using chelated iron dry onto the roots and water in about four tablespoons should do, plenty of organic matter in topsoil. They really benefit from trace elements added to our calciferous Florida soil. I had a tree that had curled leaves and a little yellowing and it responded really well to feeding it minerals as well as a manure type fertilizer. They are slow, but need complete nutrition for optimal growth. Good Luck!
 

Did not see the fruit on the Triumph and some trees had been removed before my return October of last year. We shall see next season.

Ilama is more sensitive to cold and conditions that Atemoya and Sugar Apple. Here at The treehouse we have an aged plant that my parents brought back from El Salvador. It is Pink and has wonderful fruit. We will be propagating and have later this year.