We discovered a simple yet highly successful treatment that has fully recovered our peach tree from fungal infection.
The earliest symptoms were curly leaves, and significant leaf drop. We missed the critical period to recover the tree from infection which is as early as possible and typically in early winter.
We regularly cook rice and one day my wife saved the rice water to put on the peach tree.
Apparently, rice water is a good source of potassium and many other nutrients. See below for before and after pictures and further information.

Rice water contains many nutrients that can benefit plants, including:
Starch
Plants use the starch in rice water to store energy for growth and reproduction.
Nitrogen, phosphorus, and potassium
These nutrients are essential for plant growth and are represented by the acronym NPK.
Other nutrients
Rice water also contains beneficial nutrients like iron, calcium, magnesium, sulfur, and B vitamins.
Beneficial microbes
Rice water contains microbes like lactobacilli and mycorrhizae fungi that can improve soil health.
Rice water can be used as a natural fertilizer to help plants grow bigger and fuller, and to increase their resistance to pests and diseases. It can also enhance the flavor of fruits and vegetables.
One of the symptoms was a sudden total production of fruit all over the tree. Like it was trying to signal its value to be saved.
After one or two small buckets of rice water, it was completely transformed. There were fresh new leaves, the fruit is now doing well and in continuing abundance.
Highly recommended solution.