Hello. The “glue” on the peach trees (also known as gummosis) is not a disease in itself, but a reaction of the trees to stress caused by various factors, such as diseases (e.g. moniliosis), pests (especially leafminers), mechanical injuries, cracks caused by temperature fluctuations or frost, drought, pruning in conditions of high humidity, etc.
In this case, you can try cleaning the sap with a sharp, disinfected tool until healthy wood is visible. Then apply a copper-containing solution to the wounds, such as . One sachet of is dissolved in a small amount of water to form a paste. After disinfecting thoroughly with the blue solution and allowing it to dry, you can apply a healing product, such as or . Also, during this period, it is recommended to carry out treatments specific to the dormancy period (Winter treatments with oils and copper-based products), using a copper fungicide, such as , or , followed by a treatment with horticultural oil: , or .
In the future, in order to avoid the appearance of gummosis, it is recommended to maintain the general health of the trees by ensuring adequate humidity, by pruning at optimal times, by ensuring a balanced fertilization and by carrying out treatments during the vegetative period, according to the phenotype.