I have a problem with apricot. It blossomed remarkably, everything was fine, the fruits were tied, and then the leaves began to turn yellow sharply and in a couple of days almost eighty percent fell. After that, the apricot looked like in the late autumn, it did not throw off the fruits, the fox was yellow and in the hole. After about a couple of weeks, new green leaves began to grow on the young branches, which had already grown this year. The leaves remained green, but holes appeared on them again.
Despite the fact that apricot is resistant to disease, but still fungal diseases affect it. Most likely it happened with your tree, he was struck by clusterosporiasis. This fungus lives in diseased kidneys, on shoots, as well as in wounds of apricot. And in the case when the leaves are affected too much, they turn yellow and fall off. Since the fungus winters wonderfully in fallen leaves, I advise you to carefully remove and dig up the trunk area after falling off. Also sprinkle apricot with one of such preparations as copper sulfate, Bordeaux liquid, or nitrofen.