This issue has been persistent since last year. Tree is 3 years old
Thank you for contacting the Toronto Master Gardeners
It would appear that you have some type of leaf spot disease on your peach tree.
It is important to note that some leaf spot diseases are caused by fungi; some by bacteria. A large number of fungi and bacteria cause spots on plant leaves, in a variety of colors, shapes and sizes. In some cases the spots may spread to cover entire leaves, stunting plant growth. Other leaf spots have centers that die and fall out of the leaf, giving a ragged or ‘shot-hole’ effect to the leaf. Infected leaves turn yellow and drop from the tree. Extended periods of wet weather encourage the spread and development of the bacteria.
With any disease of this type, the best practice is to remove the affected leaves and destroy the leaf debris, and this includes leaves that fall at the end of the season because often spores or bacteria will overwinter in fallen leaves, or in twigs. Do not put the leaves in your compost but put them either in the City of Toronto’s leaf pick up or the garbage. Your compost will not get hot enough to destroy fungi and spores. Keep your tree well pruned to promote air circulation and promote rapid drying of foliage and fruit.
The following links will take you to websites which discusses leaf spot diseases.
https://extension.psu.edu/stone-fruit-disease-bacterial-spot
https://www.canr.msu.edu/news/management_of_bacterial_spot_on_peaches_and_nectarines
http://omafra.gov.on.ca/english/crops/gardbk/gh-ch5-4tdr.htm#12
http://www.omafra.gov.on.ca/IPM/english/tender/diseases-and-disorders/bacterialspot.html
We also have a several helpful Q&A posted on our website ( torontomastergardeners.ca) that deal with leaf spot. Simply, type “leaf spot” in the ‘Find It Here’ search box to the right.