Gummosis is the formation of patches of a gummy substance on the surface of certain plants, particularly fruit trees. This occurs when sap

Sap

Sap may refer to:* Plant sap, the fluid transported in xylem cells or phloem sieve tube elements of a plant* Sap , a village in the Dunajská Streda District of Slovakia...

 oozes from wounds or canker

Canker

Canker and anthracnose are general terms for a large number of different plant diseases, characterised by broadly similar symptoms including the appearance of small areas of dead tissue, which grow slowly, often over a period of years. Some are of only minor consequence, but others are ultimately...

s as a reaction to outside stimuli

Stimulus

Stimulus may refer to:*Stimulus , something external that influences an activity*Stimulus , a concept in behaviorism and perception*Input to a system in other fields*Economic stimulus:...

 such as adverse weather conditions, infections, insect problems, or mechanical damage. It is understood as a plant physiological

Plant physiology

Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology , plant ecology , phytochemistry , cell biology, and molecular biology.Fundamental processes such as photosynthesis, respiration, plant nutrition,...

disease.